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John Deere JS38 push mower

#1

D

dannac

Have a John Deere JS38 push mower.
Purchased in 2012 and has worked great.

Sometimes bag grass, and stop engine to empty clippings.
Never had problems with it re-starting until end of last season.

When I stop it to empty clippings, it will not start unless I leave it sit for approx 15 minutes ... as if it's flooded.

Oil was changed every year, and occasional changing of spark plug with most recent last year.

Appreciate some advice or something to check.

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#2

M

mechanic mark

Adjust intake & exhaust valves with engine cold.

Briggs and Stratton Valve Clearances

outdoorpowerinfo.com outdoorpowerinfo.com
Scroll down above page for your engine valve clearance specs. B&S Engine Model # should be on sticker, specs. plate, or stamped on blower housing.
Watch video below & see if you're up to adjusting valves.


#3

D

dannac

mechanic mark said:
Adjust intake & exhaust valves with engine cold.

Briggs and Stratton Valve Clearances

outdoorpowerinfo.com outdoorpowerinfo.com
Scroll down above page for your engine valve clearance specs. B&S Engine Model # should be on sticker, specs. plate, or stamped on blower housing.
Click to expand...
Thanks for the reply ... but that is probably over my head.

I've never taken an engine apart which I'm assuming I'd have to do to get to the valves.
... and if I got there I wouldn't know the intake valve from the exhaust valve or how to adjust.

Thanks


#4

D

dannac

Engine info it that may help

JDengine01.jpg


#5

M

mechanic mark

Results

www.briggsandstratton.com www.briggsandstratton.com
Engine Specs. see Operators Manual page 10 above.
Intake .005- .007, i would set at .006, Exhaust .007-.009 i would set at .008.
or you can do as you choose dannac: Intake .005 Exhaust .007 or Intake .007-Exhaust .009
Take your time & let us know how it goes, thanks dannac, Mark


#6

D

dannac

Thanks Mark ... looked at the video, pretty sure I can handle that.

What I'm not sure of is the clearance values to use.


#7

F

Freddie21

I usually go midway between specs. .006 and .008


#8

grumpyunk

grumpyunk

You have what is known as a 'flat head' engine per the diagram at partstree.com. As the valves wear, the tip of the valve will get closer to the tappet which opens the valve when the cam lobe pushes on it. There must be clearance between tappet and the valve stem or the valve will not close which causes loss of compression.
The symptom is that it happens when the engine is hot. The valve expands in length as it heats up, reducing the clearance until the valve barely seats on the top of the engine(valve seat). That makes it hard to start when it gets hot.
You can usually remove the head and then the tappet cover and finally the keeper and spring from the valve stem. You can then push the valve out of its guide. Use a grinder or file to remove a few thousandths off the tip of the valve stem. Best to keep the tip square so it meets the tappet nicely. Put the valve back in place and use a 'feeler gauge' to measure the gap between valve stem tip and tappet.
You can likely improve the way the engine runs by lapping the valves. Search for the process, but essentially it is using a paste that has abrasive between valve and seat to make the meeting surfaces meet better and thus seal better. Not difficult, and generally after that many years, the seats are tired and need a freshening. You will more than likely regain a lot of lost power and the engine will also likely use less fuel.
Kind of a fun project to learn about small engines at a low cost.
tom


#9

D

dannac

Thanks for the reply Freddie21.

Thanks for that info tomw0 ... your explanation makes sense to me.

I took cover off and not sure if I want to try this with the cutting season starting.
May have to wait, as this would take me quite awhile not being familiar with this.

Did notice a little liquid at bottom of air filter frame, gas I think.

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#10

Z

Zue

dannac said:
Have a John Deere JS38 push mower.
Purchased in 2012 and has worked great.

Sometimes bag grass, and stop engine to empty clippings.
Never had problems with it re-starting until end of last season.

When I stop it to empty clippings, it will not start unless I leave it sit for approx 15 minutes ... as if it's flooded.

Oil was changed every year, and occasional changing of spark plug with most recent last year.

Appreciate some advice or something to check.
Click to expand...
Sometimes the electric coil for the spark plug can heat up and stop working. Check the spark from your coil going to the spark plug and make sure that is still working when you try to restart your motor. Coils tend to fail when they get hot not when they’re cold.


#11

G

Gescha

dannac said:
Have a John Deere JS38 push mower.
Purchased in 2012 and has worked great.

Sometimes bag grass, and stop engine to empty clippings.
Never had problems with it re-starting until end of last season.

When I stop it to empty clippings, it will not start unless I leave it sit for approx 15 minutes ... as if it's flooded.

Oil was changed every year, and occasional changing of spark plug with most recent last year.

Appreciate some advice or something to check.
Click to expand...
You have a bad coil. When it heats up there is no fire. When it sits for a while and cools......it will work again until it gets hot.


#12

Morganfd9

Morganfd9

Gescha said:
You have a bad coil. When it heats up there is no fire. When it sits for a while and cools......it will work again until it gets hot.
Click to expand...
My thoughts exactly


#13

S

slomo

Freddie21 said:
I usually go midway between specs. .006 and .008
Click to expand...
I go for tight for max power/torque.


#14

D

dannac

Well cutting season about over ... and the JD died about 2 weeks ago. Will not start ... period.

When this post started .... it would run .... but if I stopped it, it would not start until it cooled down.
I'm ready to try and fix, if I can.

It was mentioned my valves needed adjusting or maybe a bad coil.

I'm willing to take it a part now, so that's why I'm back.

Is there a way to check the coil ?


#15

R

Rivets

To check the coil remove the kill wire from the coil and check for spark. No spark, bad coil.


#16

D

dannac

Was not sure how to check coil for spark but read article on checking resistance with meter.

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#17

R

Rivets

With today’s coils you can forget about resistance tests, as they contain a Hall effect trigger which can be only checked with a very $$$$ piece of equipment. Most techs and many DIY guys use an inline tester. If you don’t have one available I set the plug on the engine and check to see if I’ve got spark. Low light conditions make it easier to see a spark.


#18

D

dannac

thanks .... will put back together and test


#19

D

dannac

got good spark ....

so in the last image i posted .... or the valves near the front ( spark plug side )
or
do i need to get to valves from top


#20

F

Freddie21

Doesn't matter as it's not going to start. Remove the plug and reinsert it into the plug wire. Touch the body of the plug to somewhere to a metal part of the engine and turn the key. You should see the spark jump on the tip of the plug. If it doesn't try another location to touch it to. If it does spark, it indicates the coil and plug are good. Reconnect the kill wire on the coil. Try it again. If no spark, you have a safety, or something, giving a ground to the kill wire. Happy hunting.


#21

D

dannac

Freddie21 said:
Doesn't matter as it's not going to start. Remove the plug and reinsert it into the plug wire. Touch the body of the plug to somewhere to a metal part of the engine and turn the key. You should see the spark jump on the tip of the plug. If it doesn't try another location to touch it to. If it does spark, it indicates the coil and plug are good. Reconnect the kill wire on the coil. Try it again. If no spark, you have a safety, or something, giving a ground to the kill wire. Happy hunting.
Click to expand...
Connected kill wire back to coil ... pulled cord and no spark.

Held down switch arm as my normal starting procedure and had spark.


#22

F

Freddie21

Did it run? If not shoot some carb cleaner, brake cleaner or a little gas in the carb and see what happens.


#23

D

dannac

Spark plug was not in housing, was sitting on engine so I could see if it would spark.

Had stopped running about 3 weeks ago ... while I was cutting ( plenty gas ) and has not started since.

So if it's not the coil, I'll have to re-visit the post where members suspected the valves, early on in this thread.

Thanks


#24

F

Freddie21

Did you try putting it back together and starting it. You have spark, shoot in gas and there is air. That's all it takes.


#25

D

dannac

Freddie21 said:
Did you try putting it back together and starting it. You have spark, shoot in gas and there is air. That's all it takes.
Click to expand...
I don't know what you mean by "shoot in gas or carb cleaner " ... where ... how


#26

F

Freddie21

Take the air filter out and you should see the hole of the carb. Pour a thimble amount of gas in it and pull the rip cord. If it attempts to start add a little more and try it again. If it will run for a second or two then it tells you you're not getting fuel through the carb. It may be a clogged fuel filter, if there is one, or a plugged carb.


#27

D

dannac

Thanks .... will try tomorrow


#28

D

dannac

Freddie21 said:
Take the air filter out and you should see the hole of the carb. Pour a thimble amount of gas in it and pull the rip cord. If it attempts to start add a little more and try it again. If it will run for a second or two then it tells you you're not getting fuel through the carb. It may be a clogged fuel filter, if there is one, or a plugged carb.
Click to expand...
A little gas in carb has made no difference.

Gave it 8 pulls, always started with 2 or 3 pulls.

I'll continue taking it a part.


#29

D

dannac

Got back to mower and was going to remove coil as it seems it has to come off to get to valves.
While taking pictures to help me remember where stuff goes ... wanted to check spacing to flywheel. Have no guages but will get some.

Used photo paper which has a little thickness .... and the 2 spaces to flywheel are not even.
In fact one would not allow the photo paper to go through.

I tested the screws for tightness and both seemed tight, so must have been that way.

So back to see if this is relevant or not.

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#30

R

Rivets

Grab a good business card, loosen the coil and pull it back and tighten down. Rotate the flywheel until both magnets are across from the two legs of the coil. Insert business card into the gap, and loosen the coil, it should snap tight to the magnets. Tighten the coil down and rotate the flywheel to remove the business card. Test for spark.


#31

D

dannac

Rivets said:
Grab a good business card, loosen the coil and pull it back and tighten down. Rotate the flywheel until both magnets are across from the two legs of the coil. Insert business card into the gap, and loosen the coil, it should snap tight to the magnets. Tighten the coil down and rotate the flywheel to remove the business card. Test for spark.
Click to expand...
Would the spacing condition of the coil now stop the mower from starting ?

The spark plug against engine did have spark.

Thanks for reply


#32

woodstover

woodstover

dannac said:
Thanks for the reply Freddie21.

Thanks for that info tomw0 ... your explanation makes sense to me.

I took cover off and not sure if I want to try this with the cutting season starting.
May have to wait, as this would take me quite awhile not being familiar with this.

Did notice a little liquid at bottom of air filter frame, gas I think.
Click to expand...
You can handle this, adjusting the valves is a 30 min job for beginners. I wouldn't get carried away with Grumpyunk's suggestion just yet, just set your clearances to .007". Make sure your valve cover gasket is in good condition or better yet replace it so you don't end up with oil leaks.


#33

D

dannac

You can handle this, adjusting the valves is a 30 min job for beginners. I wouldn't get carried away with Grumpyunk's suggestion just yet, just set your clearances to .007". Make sure your valve cover gasket is in good condition or better yet replace it so you don't end up with oil leaks.
Click to expand...

Seems the valve cover gasket is in good shape and stayed intact.

Sure does not look like some of the YT videos I've watched on adjusting valves.
Not seeing how to make valve adjustments yet.

The cover I took off is where the spark plug was ... is this the wrong spot ?

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#34

R

Rivets

Dannac, you are giving us bad info which is not helping your case. First you tell us you have an engine with a model number of 128M02-0423-F1. This number, when looked up is an L-head engine. In your last post your show us pictures of an OHV engine. Either you are trying to pull a fast one on us or someone has switched shrouds on your engine. This has caused a MAJOR problem for those who are trying to help you, as we have no idea of what you have, so some members are posting troubleshooting procedures for an L-head engine and others are post troubleshooting procedures for an OHV engine. That is the reason for all the conflicting posts. You need to clear this up, before you will get any good help. No need for anyone to post here any more until you tell us what is going on.


#35

D

dannac

Rivets said:
Dannac, you are giving us bad info which is not helping your case. First you tell us you have an engine with a model number of 128M02-0423-F1. This number, when looked up is an L-head engine. In your last post your show us pictures of an OHV engine. Either you are trying to pull a fast one on us or someone has switched shrouds on your engine. This has caused a MAJOR problem for those who are trying to help you, as we have no idea of what you have, so some members are posting troubleshooting procedures for an L-head engine and others are post troubleshooting procedures for an OHV engine. That is the reason for all the conflicting posts. You need to clear this up, before you will get any good help. No need for anyone to post here any more until you tell us what is going on.
Click to expand...
Thanks for the reply Rivets .... maybe we can get it cleared up.

I’ll be 70 yr old next month ... and beleive it or not, I got much better things to do than run around in circles on an internet lawn mower forum. Pull a fast one ... never.

I’m relaying info and answering questions best I can with something I’m not very familair with.

The only reason I posted the last picture ( from my riding mower, not the probllem push mower ) with the OHV cover, was to show what I see on youtube when looking for “how to adjust the valves” ... and to relay that ... my engine DOES NOT have that.
( I removed that image if causing confusion )

All the other images I’ve posted are directly from the problem engine. ( I’ll post the 1st 2 again )

Again, thanks for the reply.

Attachments







#36

R

Rivets

Well that does clear some things up, but does creat other problems. First I’m well north of 70 so age has nothing to do with it. How well you understand the operation of a small engine means everything in this case. Your first mistake was watching boobtube videos and believing that the person who posted knew what they were doing. Second, you didn’t know there was a difference between L-head and OHV engines which greatly contributed to the problem. Checking and adjusting valve clearance on an L-head engine is about 50 times harder for a DIY guy, than an OHV engine. That is why I never recommend the DIY guy’s attempt this, as you can cause expensive problems very quickly.
At this point I don’t know how to help you in this thread, because it has become so confusing with correct and misleading information. Trying to figure out which posts are good and which ones are bad is not something I want to attempt. Maybe someone else would like to try to tackle it. You’ll have to decide how you want to proceed, but as you said earlier, you might be over your head.


#37

D

dannac

Now that you explained ... I must have the L-head engine.
When I remove the cover where the spark plug is, I only see the piston and 2 valves ... nothing to adjust. ( images above )

I would be over my head if I have to go deeper into the engine.

Thanks for reply.


#38

R

Rivets

From rereading this thread I personally doubt that your problem is valve clearance. If it had come to me I would have suspected an ignition or fuel problem. I would have started with checking for spark when hot restarting and if I had spark, I would have gone after a fuel problem. Just my opinion, but read my signature.


#39

D

dannac

Rivets said:
From rereading this thread I personally doubt that your problem is valve clearance. If it had come to me I would have suspected an ignition or fuel problem. I would have started with checking for spark when hot restarting and if I had spark, I would have gone after a fuel problem. Just my opinion, but read my signature.
Click to expand...
Haha .... your opinion on this issue is light years better than mine.

At this point guess I'll put it back together and give it another try.

The coil spacing was not equal ... would that have caused a starting problem ?


#40

R

Rivets

Yes. Did you read and follow post #30?


#41

O

Oddjob

dannac said:
Haha .... your opinion on this issue is light years better than mine.

At this point guess I'll put it back together and give it another try.

The coil spacing was not equal ... would that have caused a starting problem ?
Click to expand...
A couple of posters have told you that the coil is likely to be the problem. I agree. Coils typically fail initially when they get hot. Over time they fail completely. Rivets gave you the procedure for ruling out a failing coil. When you can’t restart a hot engine, that’s when you test for spark. Either buy a cheap inline spark tester (like $5-6 at Tractor Supply) or you pull the plug and ground it against the engine and see if you have spark. If you get spark when hot, rule out the coil and look for a fuel problem. If you get no spark when hot, that means you buy a new coil. Rivets also gave you the procedure for gapping the coil. Some of the pros here tell you to avoid cheap after market parts. If I were warranting work like they do, I would do the same. But if you are working on your own mower then I would buy a cheap coil from Amazon and if it didn’t work, return it and spin the wheel again. Time is not money for us retired folk. Good luck. The coil is low hanging fruit, go there before worrying about valves.


#42

D

dannac

Rivets said:
Yes. Did you read and follow post #30?
Click to expand...
Yes I did ... and #31 I asked if that would stop it from starting even though the spark plug had spark ... but got no reply to that question.

Thanks


#43

D

dannac

Oddjob said:
A couple of posters have told you that the coil is likely to be the problem. I agree. Coils typically fail initially when they get hot. Over time they fail completely. Rivets gave you the procedure for ruling out a failing coil. When you can’t restart a hot engine, that’s when you test for spark. Either buy a cheap inline spark tester (like $5-6 at Tractor Supply) or you pull the plug and ground it against the engine and see if you have spark. If you get spark when hot, rule out the coil and look for a fuel problem. If you get no spark when hot, that means you buy a new coil. Rivets also gave you the procedure for gapping the coil. Some of the pros here tell you to avoid cheap after market parts. If I were warranting work like they do, I would do the same. But if you are working on your own mower then I would buy a cheap coil from Amazon and if it didn’t work, return it and spin the wheel again. Time is not money for us retired folk. Good luck. The coil is low hanging fruit, go there before worrying about valves.
Click to expand...
Thank you .... will put it back together.


#44

D

dannac

With the images in post #33 .... should I try to clean the piston or valves some way ?

If yes, please give ways to clean.


#45

R

Rivets

You are going to hate me after reading this post, but you won’t be the first to do so. If you understand my post on resetting the air gap you would realize that the answer to that question was answered, as this would mean you need the proper gap on both legs of the magneto. With your lack of knowledge of how engines work, I would not recommend cleaning the piston, valves or cylinder. Could do more harm than good. I’m getting frustrated as at this point I don’t think you will solve this problem because you keep jumping around as to what you should do. This thread has covered the ignition system, fuel system and compression system, but at this point you’ve never completed diagnosing any one of those systems before jumping to another one. That is why you are getting confused and confusing those who are trying to help you. Troubleshooting small engines means to go in one direction and ruling it out before going another direction. My recommendation at this point is get a new head gasket and reassemble the engine. Then test the unit. If it is still a no go, start by troubleshooting the ignition system unit you get spark, then go after the fuel system and finally look at the compression system. Unless you use a step by step troubleshooting procedure you’ll never solve the problem unless you get very lucky. Probably my last post here until I see a more direct route on your part. Once again read my signature, as you may agree with others that I only know book knowledge and it’s time to start ignoring me. Sorry!!!


#46

D

dannac

Rivets said:
You are going to hate me after reading this post, but you won’t be the first to do so. If you understand my post on resetting the air gap you would realize that the answer to that question was answered, as this would mean you need the proper gap on both legs of the magneto. With your lack of knowledge of how engines work, I would not recommend cleaning the piston, valves or cylinder. Could do more harm than good. I’m getting frustrated as at this point I don’t think you will solve this problem because you keep jumping around as to what you should do. This thread has covered the ignition system, fuel system and compression system, but at this point you’ve never completed diagnosing any one of those systems before jumping to another one. That is why you are getting confused and confusing those who are trying to help you. Troubleshooting small engines means to go in one direction and ruling it out before going another direction. My recommendation at this point is get a new head gasket and reassemble the engine. Then test the unit. If it is still a no go, start by troubleshooting the ignition system unit you get spark, then go after the fuel system and finally look at the compression system. Unless you use a step by step troubleshooting procedure you’ll never solve the problem unless you get very lucky. Probably my last post here until I see a more direct route on your part. Once again read my signature, as you may agree with others that I only know book knowledge and it’s time to start ignoring me. Sorry!!!
Click to expand...
Beings I had it apart and easy access now ... just wanted to know if I should try to clean it ... that's all.
I've cleaned all other parts I've taken apart, so thought to check if I should clean piston / valves.

Not jumping around are looking for something new to try.
I got it ... with the engine I have a valve adjustment is over my head and do not want to try.

Putting it back together ... will not clean or mess with piston or valves.
Though may take me s day or two.

I appreciate your reply.


#47

D

dannac

Installed coil using business card as mentioned. Everything in place except spark plug.

Set spark plug against engine, held the kill switch bar in normal run position, and spark plug has immediate fire when pulling the cord.

Installed spark plug and put a little gas in tank and gave 7 or 8 pulls. Not a hint of wanting to start.

Any other ideas ... I'm willing to try.


#48

R

Rivets

Was the spark plug wet? Did you ever check for a sheared flywheel key?


#49

O

Oddjob

dannac said:
Installed coil using business card as mentioned. Everything in place except spark plug.

Set spark plug against engine, held the kill switch bar in normal run position, and spark plug has immediate fire when pulling the cord.

Installed spark plug and put a little gas in tank and gave 7 or 8 pulls. Not a hint of wanting to start.

Any other ideas ... I'm willing to try.
Click to expand...
I would take off the air filter and spray carb cleaner or starting fluid into the carburetor. Then try to start it. If it starts and then quits, you have a fuel delivery problem. If it does not start, then you have either a compression problem or an ignition timing problem. Ignition timing is easier to fix than compression, so that’s where I’d go after eliminating the possibility of a fuel problem. As Rivets has alluded, you can rule in or rule out an ignition timing problem by examining the flywheel for a sheared or deformed key.


#50

D

dannac

Nov 10, 2023

7 pulls ... no hint of starting. Pulled plug, seemed dry.

Purchased a carb cleaner spray.
Removed air filter and gave a good spray. Almost started 1st pull but started 2nd pull.
Let it run approx 1 minute and I shut it down.

Quickly noticed smoke coming from engine towards top. Not lots of smoke, but yeah smoke.
Pulled off top plastic cover, but could not tell exactly where the smoke was coming from, as it seemed to be from under the metal cover.

Let it sit about 5 minutes.
Then tried to start it again ... 3 pulls, no hint of starting.


#51

D

dannac

UPDATE : 1 hour 45 min later

2nd pull it started .... let it run for 15 sec and I shut it down ... did not see smoke

Tried to start it again ... 3 pulls and nothing


#52

R

Rivets

Ok, now we know that you have a fuel problem. If it came to me this is what I would do.
1. Remove the carb and disassemble it.
2. Give the carb a very good cleaning.
3. Purchase a new float needle, seat, float and carb bowl gasket.
4. Reassemble carb using new parts. Pay very close attention to float height, either level or slightly lower on the side opposite the float pin.
5. Install carb and test.

Read my signature.


#53

D

dannac

Rivets said:
Ok, now we know that you have a fuel problem. If it came to me this is what I would do.
1. Remove the carb and disassemble it.
2. Give the carb a very good cleaning.
3. Purchase a new float needle, seat, float and carb bowl gasket.
4. Reassemble carb using new parts. Pay very close attention to float height, either level or slightly lower on the side opposite the float pin.
5. Install carb and test.

Read my signature.
Click to expand...
Did you see post #50 ... as you made no remark about the smoke coming out of engine ?


#54

woodstover

woodstover

dannac said:
UPDATE : 1 hour 45 min later

2nd pull it started .... let it run for 15 sec and I shut it down ... did not see smoke

Tried to start it again ... 3 pulls and nothing
Click to expand...
Have you checked that you have good fuel delivery from the tank? Pull the fuel line off at the carburetor and make sure fuel is coming out of the hose at a good rate.
Follow Rivets instructions and rebuild the carb if you have good fuel flow from the tank, otherwise, remedy the restriction in the fuel flow first.


#55

R

Rivets

Yes I can read and I saw it, but you are trying to go a different direction again. I’m not worried about smoke, but if you want to go that direction I’ll get out of this thread.


#56

D

dannac

Rivets said:
Yes I can read and I saw it, but you are trying to go a different direction again. I’m not worried about smoke, but if you want to go that direction I’ll get out of this thread.
Click to expand...
geez Rivets ... just asking a simple question.

Smoke coming out the top of the motor seemed kinda relevant to me ... guess not.


#57

R

Rivets

Good Luck Sir. I’m now getting out of this thread, as I‘m just a 70+ year old retired teacher and I know when a student beats me. You might be right, that smoke might be relevant if we were looking for an oil leak.


#58

O

Oddjob

dannac said:
UPDATE : 1 hour 45 min later

2nd pull it started .... let it run for 15 sec and I shut it down ... did not see smoke

Tried to start it again ... 3 pulls and nothing
Click to expand...
You have a fuel problem. Cleaning the carb is never a bad idea but after reading from your original post, I see that the trouble began with restarting after shutting down a warmed up engine. I looked up the parts diagram for your JD js38 mower and saw that you have a thermostatically controlled choke. The engine starts with an assist from some carb spray but won’t restart. My guess, and I do mean guess, is that your choke is wide open. The carb cleaner is a good substitute for a closed choke, it acts like a primer. The thermostat switch is supposed to close the choke after you shut down, but it is sticking open. I have had this experience with these Briggs thermostatic chokes. I try exercising the thermostatic switch by hand until it springs back on its own. If it doesn’t spring back, buy another thermostat. You can see a good video on this switch and how to fix or replace it by googling Taryl Fixes All along with “autochoke”. I don’t know what the smoke was about. If it is gray/black then likely burning oil. A little oil smoke on startup is not usually a problem.


#59

D

dannac

Rivets said:
Good Luck Sir. I’m now getting out of this thread, as I‘m just a 70+ year old retired teacher and I know when a student beats me. You might be right, that smoke might be relevant if we were looking for an oil leak.
Click to expand...
Never meant any disrespect to you.
Your choice to leave this thread ... can only thank you for the advice given.


#60

D

dannac

Oddjob said:
You have a fuel problem. Cleaning the carb is never a bad idea but after reading from your original post, I see that the trouble began with restarting after shutting down a warmed up engine. I looked up the parts diagram for your JD js38 mower and saw that you have a thermostatically controlled choke. The engine starts with an assist from some carb spray but won’t restart. My guess, and I do mean guess, is that your choke is wide open. The carb cleaner is a good substitute for a closed choke, it acts like a primer. The thermostat switch is supposed to close the choke after you shut down, but it is sticking open. I have had this experience with these Briggs thermostatic chokes. I try exercising the thermostatic switch by hand until it springs back on its own. If it doesn’t spring back, buy another thermostat. You can see a good video on this switch and how to fix or replace it by googling Taryl Fixes All along with “autochoke”. I don’t know what the smoke was about. If it is gray/black then likely burning oil. A little oil smoke on startup is not usually a problem.
Click to expand...
The smoke did not come when starting as it occasionally does from muffler or exhaust.
Came from top of the motor.

I removed the plastic cover as quick as I could but could not spot exactly where it came from.
And that only happened the first time I ran it today.

I will look into the autochoke you mentioned. Thanks for the info.

What I'm really not understanding is ... it started and ran as normal 3 times today, as long as the engine was cold.

How could that be a fuel problem ?


#61

D

dannac

Finally got back to mower and removing the carb.

Wire will easily go through hole within center of carb.

Wire will easily go through the side hole shown in image below

It will not go through the top hole to meet the side hole in image below

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#62

woodstover

woodstover

dannac said:
Finally got back to mower and removing the carb.

Wire will easily go through hole within center of carb.

Wire will easily go through the side hole shown in image below

It will not go through the top hole to meet the side hole in image below
Click to expand...
Watch and follow Steve's instructions.



#63

D

dannac

woodstover said:
Watch and follow Steve's instructions.
Click to expand...
Thanks for the video ... my carb looked as clean as the one he worked on.

Put it back together and it started 2nd pull.
Had put the bagger on and bagged some leaves for about 10 minutes.

Stopped it to empty the bag and it would not re-start.
Seems I'm back to the original problem.


#64

woodstover

woodstover

dannac said:
Thanks for the video ... my carb looked as clean as the one he worked on.

Put it back together and it started 2nd pull.
Had put the bagger on and bagged some leaves for about 10 minutes.

Stopped it to empty the bag and it would not re-start.
Seems I'm back to the original problem.
Click to expand...
Check your main jet again (float bowl bolt) and see if it's plugged up again.


#65

D

dannac

woodstover said:
Check your main jet again (float bowl bolt) and see if it's plugged up again.
Click to expand...
It was running until I hit the kill switch ... how would the main jet be clogged ?

Just tried starting again .... after cooling for about an hour, started 1st pull.


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