Export thread

I had tried everything to my 10424 to quit surging and it still wanted to surge after three carb cleanings. Today as a last resort i changed the throttle plate to the one with a larger hole and still surging. Then i got Briggs part number 801308 and replaced the pilot jet. When i started that motor it roared to life with absolutely no surging and no smoking! If any of you have duraforce engines and have not performed this upgrade it will blow your mind the difference. It burbles like an F until you sink it in some thick grass and then i have never heard the governor on an f kick in like the duraforce did today. Every duraforce that i get will have this upgrade performed. The best part is you don't even have to pull the carb to do it because the jet is on the outside left of the carb. I don't know if anyone has started a tread about this in the past but just thought i would share!

for sharing!

Thank you. I have one that I will have to do this to.

Thanks for the info. I am certainly going to change to the bs pilot jet on my Duraforce LB's.

Ok I have an update it the idle jet. I ordered 10 of the Briggs part number jets and they have a much smaller hole than the one my friend gave me. I put the briggs part in and it surged a little at the beginning then leveled out once warm. It wad not near as easy to start as the one given to me. I think the hole is a little bigger than the one that came on the mower but it is smaller than the one he gave me that made such a big difference. The one that made such a big difference is out of a mikuni Wisconsin carb. All that said I am going to get some micro drill bits and drill the Briggs part to the size of the mikuni. I will report back on the sizes later.

Would you happen to know the size of the holes in the first bs pilot jet you received? Thanks.

EdBrown said:

Would you happen to know the size of the holes in the first bs pilot jet you received? Thanks.

Click to expand...

Its an actual mikuni jet out of a wisconsin robin not a b and s and i would have to guess its a #74 or 75 on the pilot jet on the outside of the carb. i reamed the b and s out to a #77 the other day and it still surged for a second then stopped. i am maybe going to go with a #74 or 75 on monday. i will post results.

Punching jets (as mechanics call it) has been around for a long time. We started doing it when Tecumseh came out with the nonadjustable AutoMagic carb in to late 70's. Don't tell anyone, as it still works on the new Chinese carbs your seeing today. A couple tricks to pass on to those who are thinking about trying it. Most of todays carbs are bored to .018-.0135" which is between number drills 77-80. Only use number drills between 73-77 on today's carbs. For those that may not know it, there are half sizes, which may or may not be labeled. Example, #76=.020 and #77=.018 but there is a drill size .0197. Anything larger is you will cause a too rich condition which you can't control. Make sure that you drill very wet, I use a very light synthetic oil. Drilling dry can cause a rough surface and burrs. Never punch the high speed and idle at the same time, you'll be buying new jets the next day. Never punch the jets before you have tried throughly cleaning the carb first. Finally, make sure that you are using a good quality drill and go slow.

I certainly respect you experts and you ability and knowledge to "punch jet" but I would prefer to spend a little money to solve the problem. I have an older unit, 2 in fact, that starve for fuel, and have to be primered constantly until warm. They surge, can be very hard to start and generally are a pain. I would be happy and please to:
A install a different carb
B install the carb parts that will make them run well.

It has been suggested I need a couple of springs on the carb but I don't know a part number.

Will this idel jet work on my model 10247?

kirkbrit said:

I certainly respect you experts and you ability and knowledge to "punch jet" but I would prefer to spend a little money to solve the problem. I have an older unit, 2 in fact, that starve for fuel, and have to be primered constantly until warm. They surge, can be very hard to start and generally are a pain. I would be happy and please to:
A install a different carb
B install the carb parts that will make them run well.

It has been suggested I need a couple of springs on the carb but I don't know a part number.

Will this idel jet work on my model 10247?

Click to expand...

It would seem so but i need to know the serial number to make sure.

MODEL
10247
Type/sn
200006838

kirkbrit said:

MODEL
10247
Type/sn
200006838

Click to expand...

\
Sorry i meant that i need the serial number for your model 10424.

impalass said:

\
Sorry i meant that i need the serial number for your model 10424.

Click to expand...

I did not start this thread, turfboy1997 owns it and the thread. I just posted about an older LB hoping to solve a problem easily. Maybe he'll share the SN so I'll know if the part he advocates will work on my mower. I am a little lost about all this.
:confused2:

kirkbrit said:

I did not start this thread, turfboy1997 owns it and the thread. I just posted about an older LB hoping to solve a problem easily. Maybe he'll share the SN so I'll know if the part he advocates will work on my mower. I am a little lost about all this.
:confused2:

Click to expand...

I checked both models for the year 2000 and the part is the same.

first i would try the idle jet replacement because you dont even have to remove the carb. second all duraforce mowers have the same carb so it dosent matter what serial it is. lately i have been drilling both jets with great success. it is scary what the engine sounds like when this is performed. all i know is all duraforce mowers will have the pilot and main nozzle drilled even if they are not surging. the most important thing is they run cooler too which is easier on everything. good luck.

turfboy1997 said:

first i would try the idle jet replacement because you dont even have to remove the carb. second all duraforce mowers have the same carb so it dosent matter what serial it is. lately i have been drilling both jets with great success. it is scary what the engine sounds like when this is performed. all i know is all duraforce mowers will have the pilot and main nozzle drilled even if they are not surging. the most important thing is they run cooler too which is easier on everything. good luck.

Click to expand...

Is their a picture or diagram that will show me EXACTLY what needs to be drilled larger? If I drill do I still neeed to replaced the idle jet? All help is appreciated!

Is there a good and easy to install carb I can buy to replace the OE?

kirkbrit said:

Is their a picture or diagram that will show me EXACTLY what needs to be drilled larger? If I drill do I still neeed to replaced the idle jet? All help is appreciated!

Is there a good and easy to install carb I can buy to replace the OE?

Click to expand...

Too much money for a carburetor. Why not try to buy a jet then you just have to change it which is very easy to do. If you drill the jet larger you don't have to replace it.

You are up early! Do you or anyone have a link that shows these jets? It sounds like there is more than one.

kirkbrit said:

You are up early! Do you or anyone have a link that shows these jets? It sounds like there is more than one.

Click to expand...

This is link to the carburetor schematic which shows just the main jet. I can't find a picture of the idle jet so you have to ask turfboy for a picture
Go to partstree.com to see all the parts

http://images.partstree.com/?l=lawn_boy&p=3323_468\image\_4680009&nd=0&z=30

Is it #16 or #7 or something else?

kirkbrit said:

Is it #16 or #7 or something else?

Click to expand...

the main jet is #8. Go to partstree.com then enter lawn boy and model number. If you have a problem let me know.

The problem is the not the whole carb it is the main jet and idle jet they are too small. You can find at least 10 stories on here in the last year about surging and the EPA ruining the Duraforce with this modular carburetor. Since there is no altitude adjustment the drill is your option. If you buy that 175-200 dollar carb it might work for a year or two but the problem is the same. Welcome to the world of Duraforce! You can find micro drill sets online and you will need numbers 60-80. I think my two are 67 and 77 and every machine works great! Go slow and don't ream a bunch of times. Drill in and pull out. Blow both jets out really good to get the burs out before reinstallation. You can do it!

turfboy1997 said:

The problem is the not the whole carb it is the main jet and idle jet they are too small. You can find at least 10 stories on here in the last year about surging and the EPA ruining the Duraforce with this modular carburetor. Since there is no altitude adjustment the drill is your option. If you buy that 175-200 dollar carb it might work for a year or two but the problem is the same. Welcome to the world of Duraforce! You can find micro drill sets online and you will need numbers 60-80. I think my two are 67 and 77 and every machine works great! Go slow and don't ream a bunch of times. Drill in and pull out. Blow both jets out really good to get the burs out before reinstallation. You can do it!

Click to expand...

Can you post a picture of the idle jet.

Nice machine.

http://i.ebayimg.com/00/s/NDQ3WDU5Ng==/$T2eC16R,!ykE9s7t)dHNBRuJK-6n3g~~48_20.JPG
http://i.ebayimg.com/00/s/NDQ3WDU5Ng==/$T2eC16R,!ykE9s7t)dHNBRuJK-6n3g~~48_20.JPG

The brass screw looking thing on the left side of the carb is it.

turfboy1997 said:

The problem is the not the whole carb it is the main jet and idle jet they are too small. You can find at least 10 stories on here in the last year about surging and the EPA ruining the Duraforce with this modular carburetor. Since there is no altitude adjustment the drill is your option. If you buy that 175-200 dollar carb it might work for a year or two but the problem is the same. Welcome to the world of Duraforce! You can find micro drill sets online and you will need numbers 60-80. I think my two are 67 and 77 and every machine works great! Go slow and don't ream a bunch of times. Drill in and pull out. Blow both jets out really good to get the burs out before reinstallation. You can do it!

Click to expand...

This is getting interesting enough that it's getting me curious... I need to get a Dura-Force engine so I can try this.

Thanks turfboy1997. You've done a great job posting the details. :thumbsup:

Two-Stroke said:

This is getting interesting enough that it's getting me curious... I need to get a Dura-Force engine so I can try this.

Thanks turfboy1997. You've done a great job posting the details. :thumbsup:

Click to expand...

I could have bought one today for 25 dollars and another for 75 dollars.

http://montreal.kijiji.ca/f-tondeuse-Classifieds-W0QQKeywordZtondeuseQQPageZ2

tondeuse - Laval / Rive-Nord véhicules à vendre - Kijiji Laval / Rive-Nord

Two-Stroke said:

This is getting interesting enough that it's getting me curious... I need to get a Dura-Force engine so I can try this.

Thanks turfboy1997. You've done a great job posting the details. :thumbsup:

Click to expand...

I am glad to help! I love this motor and i am sad that it get the bad name that it does because of the carburetor. In my opinion the best way to describe the duraforce is the most powerful lawn boy engine with the worst carburetor. If anyone tries the rejet and mulches remember what mulching was like before and after. It makes a huge difference! I love the F's too but they are not the duraforce when it comes to raw power that is released after a rejet. The duraforce technology was a lawn boy idea with toro's backing. so in my opinion they should be treated as part of the family! The EPA's emission standard is the real problem with the duraforce. I am just glad i have the drill bits to save as many as i can because all lawn boys are the best mowers ever made and its not even close!

impalass said:

I could have bought one today for 25 dollars and another for 75 dollars.

Petites annonces Grand Montréal gratuites - acheter, vendre, animaux, autos, immobilier - Kijiji

tondeuse - Laval / Rive-Nord v馼icules vendre - Kijiji Laval / Rive-Nord

Click to expand...

I guess kijiji.ca is Canadian version of CraigsList -- I got a re-direct to a home page when I tried that link.

Anyway... $25 is a great deal for a Dura-Force as long as you're armed with the knowledge to fix it. :thumbsup:

turfboy1997 said:

I am glad to help! I love this motor and i am sad that it get the bad name that it does because of the carburetor. In my opinion the best way to describe the duraforce is the most powerful lawn boy engine with the worst carburetor. If anyone tries the rejet and mulches remember what mulching was like before and after. It makes a huge difference! I love the F's too but they are not the duraforce when it comes to raw power that is released after a rejet. The duraforce technology was a lawn boy idea with toro's backing. so in my opinion they should be treated as part of the family! The EPA's emission standard is the real problem with the duraforce. I am just glad i have the drill bits to save as many as i can because all lawn boys are the best mowers ever made and its not even close!

Click to expand...

I am officially hooked on this now. :laughing:

I just have to find one for a good price. But I'll be patient. It's not like I don't have enough mowers already. :confused2:

Two-Stroke said:

I am officially hooked on this now. :laughing:

I just have to find one for a good price. But I'll be patient. It's not like I don't have enough mowers already. :confused2:

Click to expand...

i found one a month ago for $10 with all the attachments. The motor was locked but i had a shortblock from one i parted out a year ago that i got for another $10. cleaned the carb rejetted and sold for $150 because it ran so well. You will find one for cheap. They are starting to be discarded more and more so be patient because they are coming.

FOR IMMEDIATE RELEASE
December 11, 2001
Release # 02-060 Lawn-Boy Hotline: (800) 444-8676
CPSC Consumer Hotline: (800) 638-2772
CPSC Media Contact: Kim Dulic, (301) 504-7058
CPSC, Lawn-Boy Inc. Announce Recall of Power Mowers

WASHINGTON, D.C. - In cooperation with the U.S. Consumer Product Safety Commission (CPSC), Lawn-Boy Inc., of Bloomington, Minn., is recalling about 90,000 Lawn-Boy power mowers. Stress cracks can develop in the mower's fuel tank, allowing gasoline to leak and posing a risk of fire and burn injuries.

Lawn-Boy received nearly 400 reports of fuel tanks on these mowers leaking, and one report of a fire. No injuries or property damage were reported.

The recalled Lawn-Boy SilverPro and GoldPro Series are walk-behind, 21- inch mowers powered by 2-cycle Duraforce engines. "Duraforce" is written on the top of the recoil starter. A decal on the right rear of the mower's housing has one of the following model numbers: 10247, 10252, 10323, 10324, 10424, 10550 or 10552. The decal also has a serial number starting with "21."

Lawn-Boy dealers, and department and home center stores sold these mowers from December 2000 through November 2001 for between $300 and $600.

Consumers should stop using these recalled mowers immediately and contact Lawn-Boy to arrange for a free replacement fuel tank to be installed. To locate the nearest Lawn-Boy service dealer or for more information, consumers should call Lawn-Boy at (800) 444-8676 anytime, or go to the firm's web site at www.lawnboy.com.

CPSC, Lawn-Boy Announce Recall of Walk-Behind Mowers

WASHINGTON, D.C. - In cooperation with the U.S. Consumer Product Safety Commission (CPSC), Lawn-Boy Inc., of Bloomington, Minn., is voluntarily recalling about 36,000 Lawn-Boy walk-behind mowers. The vendor who manufactured the mulch plates for Lawn-Boy used the wrong material, making the plates brittle and easy to crack or break if struck by a stone or stick while mowing. Objects coming through a broken plate or pieces of the plate could possibly injure the operator or bystanders.

Lawn-Boy has received five reports of broken mulch plates. No injuries or property damage have been reported.

The recall includes 21-inch Lawn Boy Easy Mulch Silver, Silver Pro and GoldPro Series walk-behind lawn mowers. The mowers have the words "EASY MULCH" printed on the top of the mulch cover plate in bold black letters. A model and serial plate is located on the right rear of the mower housing.


Model Numbers Serial Numbers
10247
10247C (Int'l)
10323
10324
10324C (Int'l)
10360
10360C (Int'l)
10361
10424
10550
10552 220004832-220009307
220000001-220000899
220012370-220022449
220004926-220015029
220000001-220000300
220002506-220004005
220000001-220000300
220003798-220005795
220001738-220003521
220001896-220005900
220001572-220002569



Lawn-Boy dealers, department and home center stores sold the mowers nationwide from February 2002 to August 2002 for between $250 and $580.

Consumers should stop using these mowers in the mulching mode immediately and contact Lawn-Boy to receive a replacement cover plate. For more information, consumers can contact Lawn-Boy toll-free at (866) 336-5207 between 8:30 a.m. and 9:00 p.m. ET Monday through Friday, 8:30 a.m. to 5:00 p.m. Saturday, and 10:00 a.m. to 6:30 p.m. Sunday. Consumers may also visit the firm's web site at www.lawnboy.com

turfboy1997 said:

The problem is the not the whole carb it is the main jet and idle jet they are too small. You can find at least 10 stories on here in the last year about surging and the EPA ruining the Duraforce with this modular carburetor. Since there is no altitude adjustment the drill is your option. If you buy that 175-200 dollar carb it might work for a year or two but the problem is the same. Welcome to the world of Duraforce! You can find micro drill sets online and you will need numbers 60-80. I think my two are 67 and 77 and every machine works great! Go slow and don't ream a bunch of times. Drill in and pull out. Blow both jets out really good to get the burs out before reinstallation. You can do it!

Click to expand...

Do I ream out both the pilot (or idle) jet (no. 5 on the schematic) or the main jet (no. 8 on the schematic) or both?

Also what size micro drill bits do I use for each? The schematic indicates that the pilot jet is 37.5 and the main jet is 77.5.

One more thing: If I need to replace jets, should I purchase replacement Lawnboy jets or use someone else's jets?

Thank you.

2004lawnboy10424 said:

Do I ream out both the pilot (or idle) jet (no. 5 on the schematic) or the main jet (no. 8 on the schematic) or both?

Also what size micro drill bits do I use for each? The schematic indicates that the pilot jet is 37.5 and the main jet is 77.5.

One more thing: If I need to replace jets, should I purchase replacement Lawnboy jets or use someone else's jets?

Thank you.

Click to expand...

Well i think i misspoke on the sizes of bits i purchased. I think the bits i bought were closer to 39 and 79 maybe? I would buy a complete set of micro drill bits and see which one fits then go up one size and try it. It has been a long time since i posted this and i still have the bits and i do it to every duraforce. I would do the idle on the side of the carb and try it. If it still sounds lean do both. I do both on every machine and it makes a huge difference! Buy OEM where possible on a component such as a main jet. as for the idle jet there are several different manufacturers so i think they all will work great for you. Good luck and let us know how it goes!

I drilled out my jets and I believe it was a 67 on the main and a 79 on the idle but was advised to not get drill happy as it only takes a little bit of oversize drilling.I bought a 10323 from a guy in a package deal that I dont know what he did but that one is evil.It has a sharper crack in the exhaust note almost like a dirt bike.It must have been his favorite one of the 20 he sold me