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Honda Autochoke FAQ

Sep 2, 2014#1

robert@honda

This post will help you understand a bit more about the Autochoke system found on most modern Honda mowers, and on many other mower brands that use Honda engines fitted with Autochoke. There are also details about the Honda Service Bulletin (January 2014) related to Autochoke.

Background:
Engines with carburetors need a mixture of air and fuel to run. When an engine is cold, it needs less air at first, and after warming up, needs more air. A controllable restrictor or choke plate is used to make this work on Honda engines. Other designs use a primer bulb to manually inject more fuel for starting, but either version gets the job done by temporarily changing the mixture of fuel and air.

Until recently, many Honda engines had a manual choke built into the throttle cable and control. When you moved the throttle past the FAST position and into CHOKE, the choke plate was closed. After the engine was warmed up, you'd move the lever out of CHOKE and into FAST. This held the choke plate fully open so maximum air could flow.

However, many first-time users of mowers did not understand or realize the purpose of the choke, how to use it correctly, and this resulted in hard or no-start conditions. Further, the control cable could become bent or broken when folding the handlebars for storage, there was extra cost for the parts, exhaust emissions would be worse if the choke was used improperly, the list goes on and on, so there was a lot of good reasons to automate the choke process during engine start-up.

How Honda's Autochoke Works:
On a cold engine, a spring puts constant pressure on the CHOKE CONTROL ARM (blue) to hold the CHOKE PLATE (pink) closed. After the engine is started, heat from the engine warms up the WAX CYLINDER (yellow) causing the wax to expand, pushing the PISTON (purple) out and forcing the CHOKE CONTROL ARM into the opposite direction; the CHOKE PLATE is then opened, allowing more air to enter the engine.

When the engine is turned off and cools, the wax inside the WAX CYLINDER cools and contracts, and the SPRING pushes back on the CHOKE CONTROL ARM. The CHOKE PLATE is moved back into the closed position as the PISTON is retracted back into the WAX CYLINDER.

Common Symptoms and Issues:
If the mower is hard or impossible to start, it could be because the Autochoke is not working. There may also be many other things that can make for hard starting, so don't be too quick to think it is the Autochoke. Clogged carburetors, stale gasoline, plugged air filters, bad spark plug, etc. can and are frequently the most common reasons for poor starting and/or running issues.

Special Note About Warm-Up:
A frequent complaint is when an engine starts, but is then shut down before being fully warmed up, and then won't restart. This typically can happen when using the mower in cooler weather. If the engine is not run for at least 3 minutes, it is possible for it to not fully warm-up, but still get warm enough to activate the Autochoke. Restart attempts may fail, since the choke plate is open but the engine is still too cold to start/run with too much air flowing. If this happens, let the engine cool off a while, so the choke plate can return to the closed position, then when you restart, be sure to let the engine run for a full 3 minutes before you attempt a shut-down and restart.

How to Inspect / Check the Autochoke:
1. When the engine is completely cold, remove the air cleaner cover and filter element. Look in the opening and confirm the choke plate is completely closed.

2. If the choke plate is open, even partially, the linkage may be sticking; skip to step 4.

3. If the choke is fully closed, start the engine and let it run for at least 3 minutes. Shut off the engine and confirm the choke plate has fully opened. Allow the engine to cool for at least 30 minutes. Re-check and confirm the choke plate has fully closed. Repeat this step; the choke plate must fully open after 3 minutes of operation, and fully close after the engine has cooled for 30 minutes. If all this checks out, the Autochoke is working properly.

4. In January 2013, Honda issued a Service Bulletin about the Autochoke. A limited number of Honda mowers may have a defective Autochoke linkage (usually binding or sticking). A mower with a defective Autochoke that is still under warranty is usually repaired at no charge when done by an authorized Honda dealer. Both the Autochoke linkage and the wax cylinder and may be replaced under warranty. It is important to note not all mowers with Autochoke have a defective part, and hard or difficult starting may be caused by other problems (dirty carburetor, clogged air filter, etc.).

Where To Find The Serial Number:
Look on the back of the mower deck:

Affected Honda Mower Models & Serial Number Range
Mower Model Name Serial Number Range
HRR216K8 MZCG-8400001~MZCG-8669999
HRR216K9 MZCG-8670001~MZCG-9100553
HRX217K3 MAGA-2069723~MAGA-2199999
HRX217K4 MAGA-2200001~MAGA-2325178

What About My Honda Engine on Brand X Mower?
Check the engine serial number on the side of the engine block; it is etched, and may be hard to see, so use a flashlilght; here are the affected GCV160 or GCV190 engines that may have a defective Autochoke.

Honda GCV160 Engines:
GJAPA-1000001~GJAPA-2295257
GJAPA-1546575~GJAPA-2295257
GJAPA-1000001~GJAPA-4630773
Honda GCV190 Engines:
GJAPA-3180269~GJAPA-4630773
GJAPA-1000001~GJAPA-7147598

If you think the Autochoke is not working properly on your Honda engine, and it is on a non-Honda mower, warranty repairs must be done by a Honda Engine Dealer; find one using this link:

Find a Honda Engine Dealer

What To Do Next (if Autochoke is not working properly AND your 100% Honda mower is in the affected range):
Have a Honda Mower Dealer inspect and evaluate; they can confirm if the choke is defective, determine warranty status, and perform repairs. Be sure to have the dealer confirm what will or will not be covered under warranty before authorizing any work. Find a Honda Mower dealer using this link:

Find A Honda Dealer

How to Find Out if Your Honda Mower or Honda Engine is Still Under Warranty:
Three ways to find out:
a. Drop me a PM with the serial number; I can look it up for you.
b. Call your Honda dealer and ask them to find out.
c. Call Honda Customer Relations: 770-497-6400

Why didn't Honda contact me about this Service Bulletin?
For service issues that are NOT safety-related, Honda issues the Service Bulletin to dealers only. This Autochoke issue is not safety-related, and is covered under the factory warranty.
Safety-related issues are Product Recalls, and Honda will always send notification to registered owner by mail. Work required by a Product Recall will be done on any affected product, regardless of warranty status.

Where Can I Get a Copy of My Warranty?
Here's a link: Honda Power Equipment Warranty

Sep 4, 2014#2

BlazNT

Boo to auto choke. But very good post.

Apr 12, 2016#3

D

Dukester60

Hi!

I have one of the affected models (GVC160 MZCG 88986). Its two years old so im pretty sure its out of warranty. You would think Honda would at least honor the parts for repair. I do mower repair on the side for 20 plus years and of coarse I do my own but this is a first. My question is which parts are affected and how do I get access to them.

Just joined this forum and it looks like a keeper!!!

Dukester60

Apr 13, 2016#4

robert@honda

Dukester60 said:
Hi!

I have one of the affected models (GVC160 MZCG 88986). Its two years old so im pretty sure its out of warranty. You would think Honda would at least honor the parts for repair. I do mower repair on the side for 20 plus years and of coarse I do my own but this is a first. My question is which parts are affected and how do I get access to them.

Just joined this forum and it looks like a keeper!!!

Dukester60

Welcome, Dukester60!

Any Honda dealer can obtain parts, but probably need to be 100% sure there is an actual problem. Is the choke actually sticking open or closed? Not a hard job to swap out for updated parts. Get me the complete engine serial number and I can find out warranty status for you.

Apr 13, 2016#5

D

Dukester60

Mornin Robert,

Wow that was a very fast response!! Thank you!

I have removed the carb and actually put heat gun on the wax cylinder. The piston doesnt even come out a little. Im thinking that is the problem as when I restart it needs help. I move the choke control arm to the point that it holds the choke plate slightly open and it takes off normal.

Here are the numbers I have here at work:

MZCG8898686
Model HRR2169VKA

Thanks again for the quick response.....

Gary

Apr 13, 2016#6

robert@honda

Dukester60 said:
MZCG-8898686
Model HRR2169VKA

Gary:

Okay, that mower still has some of its original 3-year warranty remaining. Honda never received any registration details from you (I assume you bought it new) so the warranty start date would be the "Invoice Date" and this mower was invoiced on 7/10/2013, so the factory warranty will expire on 7/10/2016. :thumbsup:

Next, to see if the repair will qualify for warranty, a Honda dealer must inspect and evaluate the issue. If the dealer determines a part is defective, they make the repairs and bill Honda. I'd urge you to get this done ASAP, but spring is a very busy time, and dealers are swamped with service work.

Use this link to find a dealer close to you; be sure to check off the SERVICE box.

Find A Honda Dealer

Finally, if you have any proof-of-purchase that shows the mower was purchased AFTER 7/10/2013, bring it to the dealer so they can update your registration records, and add a bit more time to the warranty.

Apr 13, 2016#7

D

Dukester60

Actually its a friends mower and hes trying to find the receipt. You have been a HUGE help....I will let you know how things go,

Thanks again...

Apr 19, 2016#8

D

Dukester60

Hi Robert,

Gary again. I Found the parts and actually got them very quickly. Our local repair outfit says wait time 2-4 weeks so i said ok.......

My question is (the new thermowax looks alot more heavy duty) is there any special install issues procedures I should be aware of? I removed some black atv silicone when removing the original thermowax from the housing. It looks bigger initially but bim hoping its the correct one. The choke plate looks like it is improved also. I have really worked my butt off to get these parts, hoping to get this mower finished and out of my shop.

Thanks for your help....

G

May 14, 2016#9

A

asit3

Hi Robert,

Can you check it up for my Honda mower? Thanks in advance.

Model: HRR2169VKA
Sr. No.: MZCG-8696038

May 17, 2016#10

A

asit3

asit3 said:
Hi Robert,

Can you check it up whether my Honda mower is covered? Thanks in advance.

Model: HRR2169VKA
Sr. No.: MZCG-8696038

My Honda lawnmower stopped while cutting lawn and now it does not start.

I cleaned carb, replaced new spark plug however it still does not start. Could it be a choke issue?

My mower info:

Model: HRR2169VKA
Sr. No.: MZCG-8696038

Help greatly appreciated.

May 17, 2016#11

robert@honda

asit3 said:
Hi Robert,

Can you check it up for my Honda mower? Thanks in advance.

Model: HRR2169VKA
Sr. No.: MZCG-8696038

Your serial number IS in the range of mowers that MIGHT have an autochoke issue. Since your mower still has warranty remaining (3/10/2017) I'd get it up to a Honda dealer and have it inspected. If the autochoke is found to be defective, it would normally be replaced at no charge.

A few things to keep in mind:

Honda's warranty only covers defective parts, so if the problem is due to old, stale fuel clogging the carburetor, or a dirty, torn air filter, those are not defective parts, and such repairs would be out-of-pocket. Be sure you discuss with your service manager what is and what is not covered, and have the call you before authorizing any repair.

Just because your mower may have an autochoke issue does not absolutely mean it is the actual cause of the starting problem.

This is the most-busy time of the year for mower dealers...everybody wants their mower repaired but usually there is a wait involved due to the overwhelming demand for service. Many dealers will naturally put customers who bought mowers from there at the front of the line, and customers that bought elsewhere at the rear. That said, if they are a Honda dealer, they are fully authorized to perform warranty-related services to all Honda customers, including those purchased from other dealers (or Home Depot).

Are you still near ZIP code 02889? Here are the closest dealers:

American Lawnmower Service, Inc.
870 Dyer Ave
Cranston, RI 02920-6605
(401) 946-2332

All Outdoors Power Equipment
4060 Tower Hill Rd
Wakefield, RI 02879-2262
(401) 789-7997

Steve's Marine
294 Market St
Warren, RI 02885-2609
(401) 245-7673

Tom's Lawn & Garden Equipment, Inc.
1055 East Main Rd
Portsmouth, RI 02871
(401) 683-0002

Howard Johnson, Inc.
1978 Kingstown Rd
Peace Dale, RI 02879-1607
(401) 789-9375

Use this link to find other dealers:

Find A Honda Dealer

May 20, 2016#12

A

asit3

Thanks Robert.

I am in Burlington, Ontario, Canada.

May 25, 2016#13

robert@honda

asit3 said:
Thanks Robert.

I am in Burlington, Ontario, Canada.

Honda Customer Relations
180 Honda Blvd.
Markham, ON
L6C 0H9

Toll Free: 1-888-9-HONDA-9 (1-888-946-6329)
Hours: 8:00 am to 7:30 pm Mon to Fri (EST)

Jun 13, 2016#14

P

PD2

If the choke is stuck open and it's hard to start but then runs fine, take off the air filter and spray some carb cleaner inside the carb through the air/choke hole. This will get it started and some cleaner doesn't hurt since the jets are so small they get clogged easily.

Sep 13, 2016#15

J

John Davies

Robert I recently contacted you regarding the Honda choke on my mountfield mower made in the UK. My engine number was on your Honda bulletin so I had the linkage replaced and it now works fine. Did Honda sell faulty chokes to uk manufacturers? I am pursuing this with mountfield. Thanks for your help. John

Sep 27, 2016#16

S

spiffy926

Hi, I am trying to fix a GCV160 with an auto-choke. Currently the mower starts no problem, but the choke will stay on. I have let it run trying to heat up the thermo-wax but after a minute or so the choke still remained on with black smoke pouring out of the engine so I called it quits. I had the carb off for cleaning, and tried heating the thermo-wax with a propane torch and it does extend when it heats.
When I start the mower I can reach my finger under the carburetor cover and flip the choke control arm manually with my finger, and the choke will disengage and the mower will run perfectly.
If i then try to re-start the mower when it is warm, it will run no problem so that tells me that eventually the thermo-wax does extend and disengage the choke.
It sounds to me like my thermo-wax is just lethargic and does not disengage the choke quick enough. How long does the mower usually have to run to disengage the choke?

Sep 27, 2016#17

robert@honda

spiffy926 said:
Hi, I am trying to fix a GCV160 with an auto-choke.

How long does the mower usually have to run to disengage the choke?

Depends on ambient temps. On a warm day (above 80 F), no more than 5 five minutes.

Is this Honda GCV160 engine on a Honda mower, or a non-Honda mower?

Reply with the engine's serial number if on a non-Honda mower, OR, if on a Honda mower, the serial number off the back of the mower deck.

I can tell you if either the engine or mower has warranty, and if you'll include your ZIP code, where a dealer can be located near you.

Sep 27, 2016#18

S

spiffy926

Actually, looks like someone had tried to set the engine speed too high by putting the governor spring into the second hole on the governor arm.
So, it actually wasn't a problem with the choke but rather the engine seemed to be stumbling due to the increased spring pressure on the governor arm.
As soon as the engine was able to get moving in higher rpms, it would run fine and the choke functions as it should. I could give it a nudge on the governor arm, or could manually open the choke plate, both would help it get going.
But I ended up re-setting the governor spring where it should be and it starts up properly and the choke is working fine.
I guess that's what I get for letting knuckleheads work on the machine. The owner was complaining it didn't have enough power under load, so I guess someone decided to set the speed higher instead of giving the carb a once-over.

Mar 21, 2017#19

T

timlinden

My HondaHRX217 is in the list affected. Last year I had a problem, brought it to a dealer, and it was fixed under warranty. The same problem is now happening again.

Is the replacement part just the 16620-Z8D-305 or does the control assembly (16600-Z8D-840) also need to be replaced? I guess what I'm trying to figure out is if they already replaced both, why am I having a problem again.

Mar 28, 2017#20

B

buffettck

robert@honda said:
Depends on ambient temps. On a warm day (above 80 F), no more than 5 five minutes.

Is this Honda GCV160 engine on a Honda mower, or a non-Honda mower?

I have the full Honda mower with the GCV160 engine I got from Home Depot. It's been a great mower so far and I'm just starting my third year/season using it. I've always wondered about the auto-choke and the engine in general as far as warming it up. After starting it, do I need to let the engine warm up for a bit or can I just start cutting grass immediately? I usually give it a 10-20sec run time before I start cutting, so is that enough? Thanks!

Apr 3, 2017#21

robert@honda

buffettck said:
I have the full Honda mower with the GCV160 engine I got from Home Depot. It's been a great mower so far and I'm just starting my third year/season using it. I've always wondered about the auto-choke and the engine in general as far as warming it up. After starting it, do I need to let the engine warm up for a bit or can I just start cutting grass immediately? I usually give it a 10-20sec run time before I start cutting, so is that enough? Thanks!

Always a good idea to let the engine run a full minute or so to get all the way warmed up. The engine RPM will stabilize and you'll have full power and torque ready to go.

Does you mower have the blade clutch (yellow button) or do the blades turn as soon as you start the engine?

Apr 11, 2017#22

B

BOOMER_SOONER

I'm having the hard start problems as described. I am wondering if I should just go and buy a new carb or verify if my model has any recalls. I didn't find my model listed however I figured I would let the experts see if I am missing something. I am going to get this mower running good again. It's having start issues, but when hot runs decent, and it does seem to have a little issue with the self driving mechanism.

HRX2172HXA
MAGA-1657249

Thanks in advance,

BOOMER_SOONER

Apr 11, 2017#23

robert@honda

BOOMER_SOONER said:
I'm having the hard start problems as described. I am wondering if I should just go and buy a new carb or verify if my model has any recalls. I didn't find my model listed however I figured I would let the experts see if I am missing something. I am going to get this mower running good again. It's having start issues, but when hot runs decent, and it does seem to have a little issue with the self driving mechanism.

HRX2172HXA
MAGA-1657249

Thanks in advance,

BOOMER_SOONER

Your mower is fitted with a manual choke, not the automatic version of newer models, some of which had choke issues. You can easily inspect the choke and rule it out as the problem...just remove the air cleaner / filter and have a helper move the throttle lever to CHOKE, and confirm the plate is closing all the way.

A new carb for your mower is quite inexpensive, and you just need a 10mm socket to remove it. Google part number 16100-Z0Y-812 to find a dealer selling one online, or use this link to locate your local Honda dealer.

Find A Honda Dealer

I'd also suggest replacing the gaskets, just a precaution, as they may have gotten a bit crusty or damaged since new; use this site (have your serial number hands) to look 'em up for your mower:

Honda Power Equipment, Engines and Marine Factory Parts Lookup

Apr 24, 2017#24

A

AFA

Can anyone tell me what grease is used in thermowax housing?...Told it is hard to remove and photos show it with some grease on it....mine was bone dry and thermowax came out very easily

May 8, 2017#25

D

DC1071

I purchased a slightly used Honda HRR2168VKA S#MZCG-8562286 and it worked great for the last two years, and has started having problems starting end of last season. I noticed the choke was not closed, removed the carb and externally cleaned everything linkage etc. reassembled it and it worked a couple of cuts then is doing the same thing this spring. started fine for the first cut but this weekend I used a touch of carb cleaner to get it started so I could cut the grass, and after noticed the choke about half open. I let it cool an hour and it never moved. I'm pretty sure it's out of warranty. is there some way to get the updated parts or a part #?

Dave

May 9, 2017#26

G

gstokes

Hello,

I am having idling problems with my Honda GCV160, this seems like a auto choke issue. The idle revs up and down at start up for about a minute and then dies. This is very consistent. The mower is only a year old. I replaced the spark plug but that made no difference. When i stored the mower for the winter i ran the fuel very low and then turned off fuel and ran mower until it ran out of gas. I filled with fresh gas 2 weeks ago so i don't think it is a fuel problem. I have been using the same fuel with my pressure washer and it runs great.

Can you tell me if getting this fixed would be covered by warranty?

Model HRR216K9VKAA
Serial # MZCG-9741642
GCV160LAO MY1 R280
GJARA 6663327

Thanks,

Greg

May 14, 2017#27

P

philman

Hi,
I bought a Honda lawnmower 2 years ago but just started using it last fall ( i have another cheapo walmart model I have been using for over 15 years). Its auto propel/and auto choke:

Model: HRR216VKA
Serial#: MZCG-8970458

I used it two times last fall and I took it out last week, added new gas and it wont start. I took out my old 15 year old Walmart model (its a MTD with a Brigg engine) and it started in one pull with stale gas from last year, and I always left the MTD mower out in the shed. I am very disappointed at Honda needless to say (I paid $399 at HD).

I know the Honda Mower I is just out of warranty. Is there anyway Honda can fix it for free if not how much doest it cost to replace auto-choke?

Thanks
Phil

May 17, 2017#28

robert@honda

DC1071 said:
I purchased a slightly used Honda HRR2168VKA S#MZCG-8562286 and it worked great for the last two years, and has started having problems starting end of last season. I noticed the choke was not closed, removed the carb and externally cleaned everything linkage etc. reassembled it and it worked a couple of cuts then is doing the same thing this spring. started fine for the first cut but this weekend I used a touch of carb cleaner to get it started so I could cut the grass, and after noticed the choke about half open. I let it cool an hour and it never moved. I'm pretty sure it's out of warranty. is there some way to get the updated parts or a part #?

Dave

Dave: Drop me a PM with your full email address; I'll send you a copy of the bulletin and it has a full parts list. Google the part numbers to find a Honda dealer selling online, or use this link to patronize your local Honda dealer:

Find A Honda Dealer

May 17, 2017#29

robert@honda

philman said:
I know the Honda Mower I is just out of warranty. Is there anyway Honda can fix it for free if not how much doest it cost to replace auto-choke?

Thanks
Phil

Honda pays the dealer 1/2 hour of their published labor rate to do this job under warranty. So, if they charge $60 per hour, they should only charge you $30 in labor costs, but understand Honda has no control over what independent dealers charge for service work.

The parts needed (choke assembly, thermowax) will run about $25 retail price.

May 17, 2017#30

B

brisbanex2

Hi,
I have HRX2175VKA serial no: MAGA-2446616. It was never used since today. I started nicely, warmed-up, worked for few minutes - no problems, but engine is not starting when hot. After long cool-down time it is back working well but problem comes back. Spark plug is fine, it might be auto-choke issue? Is my mower still on warranty?

Thanks a lot!
Regards

May 17, 2017#31

P

philman

robert@honda said:
Honda pays the dealer 1/2 hour of their published labor rate to do this job under warranty. So, if they charge $60 per hour, they should only charge you $30 in labor costs, but understand Honda has no control over what independent dealers charge for service work.

The parts needed (choke assembly, thermowax) will run about $25 retail price.

Thanks You Robert, Can you give me the part# for the mentioned part number? Sounds like pretty easy to change it for $25.
Many Thanks!
Phil

May 18, 2017#32

robert@honda

gstokes said:
Can you tell me if getting this fixed would be covered by warranty?

Model HRR216K9VKAA
Serial # MZCG-9741642
GCV160LAO MY1 R280
GJARA 6663327

Thanks,

Greg

Any defective parts are covered under warranty. Your problem could be a defective choke, or decayed/stale fuel. It's up to the dealer to determine if the problem is due to a failed part or neglect.

For your specific mower, Honda never received a registration card, nor did the original owner register online with Honda. This is important, as it documents the start of the 36 month warranty. If you have any paperwork, reciept, credit-card statement, etc. that would document the date of purchase, Honda can 'reset' the warranty start clock to that date. Without any proof of date of purchase, Honda only has the wholesale date (when Honda sold it to the Home Depot). Home Depot does not keep records of every single mower sale. The good new is your mower was wholesaled to Home Depot on 5/13/2016, and so worst case is the warranty will expire on 5/13/19. But, try and find a 'younger' document that shows actual date of purchase so you can get the full 36 months of coverage.

You can take your Honda mower to ANY Honda dealer for warranty (or regular) service; it's okay you didn't but it there, but understand some dealers do give service preferences to those customers who did buy from them. Use this link to find a local servicing dealer in your area:

Find A Honda Dealer

May 18, 2017#33

robert@honda

philman said:
Thanks You Robert, Can you give me the part# for the mentioned part number? Sounds like pretty easy to change it for $25.
Many Thanks!
Phil

Drop me a private message with your email Phil, and I'll send you complete instructions and parts lists.

May 18, 2017#34

robert@honda

brisbanex2 said:
Hi,
I have HRX2175VKA serial no: MAGA-2446616. It was never used since today. I started nicely, warmed-up, worked for few minutes - no problems, but engine is not starting when hot. After long cool-down time it is back working well but problem comes back. Spark plug is fine, it might be auto-choke issue? Is my mower still on warranty?

Thanks a lot!
Regards

The warranty on your mower expires on 4/1/2022. I'd absolutely get it to a dealer to inspect and evaluate. Warranty covers defective parts only, not things like bent blades or stale gasoline left in the tank. Curious, you list your location as 'Europe' but the serial number shows the owner to be Mr. S.A. of Rochester Hills, MI .....???

Records also show the autochoke was replaced once last month on 4/17 ???? So, the problem many not be with the autochoke, but with something else in the fuel system.

May 18, 2017#35

B

brisbanex2

Today I spend few hours figuring it out, but it is now running flawlessly. Checked autochoke-OK, carburetor and fuel system-OK. Ignition module was mounted too far from flywheel and at an angle.

It travelled quite a long way from MI USA to Poland Europe

Thanks for help!

Regards

Jul 6, 2017#36

D

deckeda

(If you read the original post here I apologize for the rant. With the mower still in the back of my truck, I couldn't see the top deck completely, and MISSED the model/serial plate.)

Last night I picked up a used mower, HRX2173HYA

serial:
MAGA-2057755 (that's outside the range of affected mowers, yet curiously exhibits the same symptom ...)

Owner said the choke sticks open. He typically had to push his finger in between the air cleaner housing and engine cover, pushing against the choke lever, to close the choke. The choke turns off after the engine warms up.

So I suppose the linkage is binding but that the thermowax is OK. I plan on taking the air cleaner cover off today and inspect.

The registration card is missing from the manual. Owner's name is Curtis [something, never got his last name] and currently lives in Franklin, TN. Says he's going to mail me the sales receipt' perhaps that will shed some light about how much warranty might be left.

Jul 6, 2017#37

T

timlinden

That's what happened with mine. When I pulled it apart the choke was easy to open/close. Replacing the thermowax was easy:
https://www.youtube.com/watch?v=bxuP0Pv25-I

Nov 28, 2017#38

J

Jimmbo

I bought my mower about 4 years ago from a Honda dealer, and it's had EXACTLY this problem all along, and my serial number does match (serial MAGA-22325430, model HRX2174VKA).

I've brought it in for multiple services, and they've never mentioned this issue, charging me for every service.

What do you guys suggest as a next step? My first concern is to have a better-working mower (they've already replaced the thermowax, but not the linkage), and sometimes it starts, sometimes it doesn't.

My second concern is to get some satisfaction for the $$$ I've spent to date on the various servicings. Am I stuck?

Mar 31, 2018#39

W

wdwalsh56

I assume my HRX2173HYA MAGA-2083101 with a engine serial #GJRA-2697634 is affected. Thank you for posting on this as for the longest time I did not know what was going on. Always had to use starting fluid to start the engine, which was told by a lawn mower mechanic can damage the cylinder walls and rings. Appreciate the insight however this is Honda's mistake, if the choke will not auto-close.

Apr 2, 2018#40

W

wdwalsh56

First, thanks for the info on the auto-choke issue. After getting over Honda design being the fault of my no start issue, I purchased a thermowax plunger and is looking forward to repairing the auto-choke. The two 10mm bolts are torque value 10nm, and suggest you purchase all the gaskets to start fresh. Download a Honda schematic to put the parts in order and start with putting the bolts on the air cleaner first.

Appreciate your info here...

Apr 2, 2018#41

B

bertsmobile1

wdwalsh56 said:
First, thanks for the info on the auto-choke issue. After getting over Honda design being the fault of my no start issue, I purchased a thermowax plunger and is looking forward to repairing the auto-choke. The two 10mm bolts are torque value 10nm, and suggest you purchase all the gaskets to start fresh. Download a Honda schematic to put the parts in order and start with putting the bolts on the air cleaner first.

Appreciate your info here...

If you are going to own this mower for a while, time to make some special tools.
Take your carburettor mounting bolts to a specalist nut & bolt shop and buy a pair that are about 1/2" to 1" shorter.
Now go home and cut the heads off then cut a screwdriver slot where the head used to be.
Screw these 2 "assembly guides" into the engine block , then slide all of the parts over them.
Being shorter than the original bolts you have enough space to engage the "Z" bend easily.
When everything is in position replace your "special tools" with the Honda bolts 1 at a time.
Put them in a sandwich bag with a name strip on it, name them and forget where you stored them safely for future use.
If your engine has studs then do the same thing after removing the studs except that you will need to tighten them back up before the air filter goes on as there will not be enough room to double nut to tighten the stud with the air cleaner on.

GEtting all those gaskets & heat shields in place is the only PIA job but this makes it a lot easier

Apr 2, 2018#42

W

wdwalsh56

bertsmobile1 said:
If you are going to own this mower for a while, time to make some special tools.
Take your carburettor mounting bolts to a specalist nut & bolt shop and buy a pair that are about 1/2" to 1" shorter.
Now go home and cut the heads off then cut a screwdriver slot where the head used to be.
Screw these 2 "assembly guides" into the engine block , then slide all of the parts over them.
Being shorter than the original bolts you have enough space to engage the "Z" bend easily.
When everything is in position replace your "special tools" with the Honda bolts 1 at a time.
Put them in a sandwich bag with a name strip on it, name them and forget where you stored them safely for future use.
If your engine has studs then do the same thing after removing the studs except that you will need to tighten them back up before the air filter goes on as there will not be enough room to double nut to tighten the stud with the air cleaner on.

GEtting all those gaskets & heat shields in place is the only PIA job but this makes it a lot easier

Thanks... Honda also makes studs just as you described for installation.

Apr 2, 2018#43

B

bertsmobile1

wdwalsh56 said:
Thanks... Honda also makes studs just as you described for installation.

Gees & I thought I was being so so cleaver.
Oh well it will at least get me one rung higher towards a reinventing the wheel award.

Apr 2, 2018#44

W

wdwalsh56

bertsmobile1 said:
Gees & I thought I was being so so cleaver.
Oh well it will at least get me one rung higher towards a reinventing the wheel award.

The Honda bolts are M6 x 1.0mm and 85mm long. Got a bolt specialty store and going to try 100mm and cut off the head, will that work? I can leave the z bend throttle link on.

Apr 5, 2018#45

W

wdwalsh56

Thought you might like to see a bad thermowax plunger.
View attachment 36832 View attachment 36832

Honda has ignored my inquiry on this issue, and I have put up with it for a lot of years. For a 10 dollar part, if I knew now, it could have been fixed a long time ago. Happy now that I know what is wrong.

Apr 5, 2018#46

B

bertsmobile1

wdwalsh56 said:
The Honda bolts are M6 x 1.0mm and 85mm long. Got a bolt specialty store and going to try 100mm and cut off the head, will that work? I can leave the z bend throttle link on.

Should be.
They do not have to come right out of the end as the last bit is quite thick.
I do a lot of fire pumps fitted with Honda engines and the idiot moron bastards who designed the set up went to great lengths to get a perfect balance inside the carrying frame, while ensuring that the outlets were exactly square to the carrying frame.
As such the carb mounting bolt sits directly in line with a frame rail and the frame itself makes direct removal of the carb impossible .
On the privately owned ones I pull the frame off, weld a new strap on the bottom to rotate the unit 15 deg in the frame so it can be serviced easily.
That can not be done on the ones the fire brigade owns, thus the alignment "tool"

Another tech I associate with turned down a couple of biro cases to do the same job

Apr 9, 2018#47

W

wdwalsh56

Thanks to this thread, one pull and started right up. The choke is wide open when warmed up.:smile:

May 28, 2019#48

P

PRob39

robert@honda said:
This post will help you understand a bit more about the Autochoke system found on most modern Honda mowers, and on many other mower brands that use Honda engines fitted with Autochoke. There are also details about the Honda Service Bulletin (January 2014) related to Autochoke.

[Thanks for the informative post on auto choke. I have run into wax motors before, particularly on my Maytag dishwasher. A wax motor (electrically heated wax) opens the soap dispenser. When it went bad I had a hard time troubleshooting it because it still worked, just not fast enough to open the dispenser before the power was removed from the motor by the timing circuit. It would seem that they get slower with age.

Jun 16, 2019#49

C

civic

robert@honda said:
This post will help you understand a bit more about the Autochoke system found on most modern Honda mowers, and on many other mower brands that use Honda engines fitted with Autochoke. There are also details about the Honda Service Bulletin (January 2014) related to Autochoke.

Background:
Engines with carburetors need a mixture of air and fuel to run. When an engine is cold, it needs less air at first, and after warming up, needs more air. A controllable restrictor or choke plate is used to make this work on Honda engines. Other designs use a primer bulb to manually inject more fuel for starting, but either version gets the job done by temporarily changing the mixture of fuel and air.

Until recently, many Honda engines had a manual choke built into the throttle cable and control. When you moved the throttle past the FAST position and into CHOKE, the choke plate was closed. After the engine was warmed up, you'd move the lever out of CHOKE and into FAST. This held the choke plate fully open so maximum air could flow.

However, many first-time users of mowers did not understand or realize the purpose of the choke, how to use it correctly, and this resulted in hard or no-start conditions. Further, the control cable could become bent or broken when folding the handlebars for storage, there was extra cost for the parts, exhaust emissions would be worse if the choke was used improperly, the list goes on and on, so there was a lot of good reasons to automate the choke process during engine start-up.

How Honda's Autochoke Works:
On a cold engine, a spring puts constant pressure on the CHOKE CONTROL ARM (blue) to hold the CHOKE PLATE (pink) closed. After the engine is started, heat from the engine warms up the WAX CYLINDER (yellow) causing the wax to expand, pushing the PISTON (purple) out and forcing the CHOKE CONTROL ARM into the opposite direction; the CHOKE PLATE is then opened, allowing more air to enter the engine.

When the engine is turned off and cools, the wax inside the WAX CYLINDER cools and contracts, and the SPRING pushes back on the CHOKE CONTROL ARM. The CHOKE PLATE is moved back into the closed position as the PISTON is retracted back into the WAX CYLINDER.

Common Symptoms and Issues:
If the mower is hard or impossible to start, it could be because the Autochoke is not working. There may also be many other things that can make for hard starting, so don't be too quick to think it is the Autochoke. Clogged carburetors, stale gasoline, plugged air filters, bad spark plug, etc. can and are frequently the most common reasons for poor starting and/or running issues.

Special Note About Warm-Up:
A frequent complaint is when an engine starts, but is then shut down before being fully warmed up, and then won't restart. This typically can happen when using the mower in cooler weather. If the engine is not run for at least 3 minutes, it is possible for it to not fully warm-up, but still get warm enough to activate the Autochoke. Restart attempts may fail, since the choke plate is open but the engine is still too cold to start/run with too much air flowing. If this happens, let the engine cool off a while, so the choke plate can return to the closed position, then when you restart, be sure to let the engine run for a full 3 minutes before you attempt a shut-down and restart.

How to Inspect / Check the Autochoke:
1. When the engine is completely cold, remove the air cleaner cover and filter element. Look in the opening and confirm the choke plate is completely closed.

2. If the choke plate is open, even partially, the linkage may be sticking; skip to step 4.

3. If the choke is fully closed, start the engine and let it run for at least 3 minutes. Shut off the engine and confirm the choke plate has fully opened. Allow the engine to cool for at least 30 minutes. Re-check and confirm the choke plate has fully closed. Repeat this step; the choke plate must fully open after 3 minutes of operation, and fully close after the engine has cooled for 30 minutes. If all this checks out, the Autochoke is working properly.

4. In January 2013, Honda issued a Service Bulletin about the Autochoke. A limited number of Honda mowers may have a defective Autochoke linkage (usually binding or sticking). A mower with a defective Autochoke that is still under warranty is usually repaired at no charge when done by an authorized Honda dealer. Both the Autochoke linkage and the wax cylinder and may be replaced under warranty. It is important to note not all mowers with Autochoke have a defective part, and hard or difficult starting may be caused by other problems (dirty carburetor, clogged air filter, etc.).

Where To Find The Serial Number:
Look on the back of the mower deck:

Affected Honda Mower Models & Serial Number Range
Mower Model Name Serial Number Range
HRR216K8 MZCG-8400001~MZCG-8669999
HRR216K9 MZCG-8670001~MZCG-9100553
HRX217K3 MAGA-2069723~MAGA-2199999
HRX217K4 MAGA-2200001~MAGA-2325178

What About My Honda Engine on Brand X Mower?
Check the engine serial number on the side of the engine block; it is etched, and may be hard to see, so use a flashlilght; here are the affected GCV160 or GCV190 engines that may have a defective Autochoke.

Honda GCV160 Engines:
GJAPA-1000001~GJAPA-2295257
GJAPA-1546575~GJAPA-2295257
GJAPA-1000001~GJAPA-4630773
Honda GCV190 Engines:
GJAPA-3180269~GJAPA-4630773
GJAPA-1000001~GJAPA-7147598

If you think the Autochoke is not working properly on your Honda engine, and it is on a non-Honda mower, warranty repairs must be done by a Honda Engine Dealer; find one using this link:

Find a Honda Engine Dealer

What To Do Next (if Autochoke is not working properly AND your 100% Honda mower is in the affected range):
Have a Honda Mower Dealer inspect and evaluate; they can confirm if the choke is defective, determine warranty status, and perform repairs. Be sure to have the dealer confirm what will or will not be covered under warranty before authorizing any work. Find a Honda Mower dealer using this link:

Find A Honda Dealer

How to Find Out if Your Honda Mower or Honda Engine is Still Under Warranty:
Three ways to find out:
a. Drop me a PM with the serial number; I can look it up for you.
b. Call your Honda dealer and ask them to find out.
c. Call Honda Customer Relations: 770-497-6400

Why didn't Honda contact me about this Service Bulletin?
For service issues that are NOT safety-related, Honda issues the Service Bulletin to dealers only. This Autochoke issue is not safety-related, and is covered under the factory warranty.
Safety-related issues are Product Recalls, and Honda will always send notification to registered owner by mail. Work required by a Product Recall will be done on any affected product, regardless of warranty status.

Where Can I Get a Copy of My Warranty?
Here's a link: Honda Power Equipment Warranty

Can this cause a backfire when engine is hot? Engine starts well when cold but it will make one backfire and starts and runs great when hot. Valves are adjusted. Wax cylinder has never been replaced and my mower falls under the serial numbers listed.

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