I hate carburetors....

[Gillbot]

My craftsman lawn tractor started giving me fits and would barely run only at full throttle. After a day of fighting with it to get my grass cut, it finally refused to run at all. I decided, "no biggie, I'll pull off the carb and clean the gunk, she'll run good as new". Oh how wrong I was!

I marked all the linkages and anything else I could find so it would be easier to reassemble, pulled the carb off, pulled off the float bowl to get the debris out of it and gave everything else a wipe down. I gave the parts and body a quick swish in a container of gas to knock everything else off. After a thorough wipe down, I put it all back together and bolted it back on the tractor. I set the choke on, turned the key and it fired right up, SUCCESS...... I thought! That thought was quickly erased when I realized the motor was racing and would not slow down even with the throttle set to slow. GREAT!

I tear the carb back off, double check everything and try again. Same result. After three (or thirty) more attempts to adjust anything and everything I could referencing the craftsman and Tecumseh small engine manual, I gave up and listed the dam thing on craigslist for sale.

It was a $100 tractor when I bought from craigslist so I refuse to put any money into it. I know a carb rebuild kit isn't that expensive but there is no guarantee that it will fix the problem. (I'll readily admit the problem is likely in the "rebuilder", aka, ME.) A carb is nearly as much as the tractor itself and it would still likely need properly adjusted, something I probably couldn't achieve considering I have both manuals and I've been completely unsuccessful thus far at getting this thing going.

I'm just aggravated that after all the elbow grease I've put into that thing to turn it into the grass cutting machine it was, a simple carb brings me to a grinding halt. O-well, it was a great little tractor while it ran. Maybe someone with more knowledge or willingness to put money into it will get her going good again. I just decided that it's a bit old and with the things I should replace on it soon, I would be better off getting a newer tractor. I mean, after all it needs new belts, four new tires, all tune-up items and a starter, plus add on the carb work it needs and I'd be into this tractor for better than a couple hundred. I might as well put that money towards a newer model and be done.

</rant>

 

[drnickriviera]

Tecumseh is your problem. I'll never go back to a Briggs engine after having Kohler and Kawasaki's

 

[Zenmervolt]

Originally posted by: drnickriviera
Tecumseh is your problem. I'll never go back to a Briggs engine after having Kohler and Kawasaki's

Huh? Tecumseh isn't related to Briggs at all...

And Briggs engines depend entirely on the line; the I/C and Vanguard lines are damn near indestructible; easily a match for anything from Kohler.

ZV

 

[PottedMeat]

I too hate carburetors. Too many little screws and linkages to mess with. But when it works it works.

...speaking of fixing engines, anybody ever get a rusty crank pulley off with ATF+Acetone 1:1? Heh I need to get a pulley off to get to the leaky crankcase gasket.

 

[spidey07]

Gillbot,

I have also struggled with carbs on small engines and am by no means an expert. I felt my man card slipping away. What i've learned is a full disassembly of the carb and soaking in a good solvent will yield good result. By soak I mean at least a two days. Diesel fuel works really well. You can google this. Or better yet look up my thread about 2 years ago regarding this very thing, lots of good help there.

As long as you've got fuel/air/spark/compression and a means to get the gas out (exhaust) you should be fine. Figure out which one is the problem, it may not be the carb.

 

[boomerang]

You either had the linkage assembled wrong or the throttle cable incorrectly adjusted. I'm guessing the former. Buy a can of carb cleaner from the auto parts store. Cleaning carburetors with gasoline isn't the hot setup. If you could clean a carb with gas, it would never need cleaning.

There's a governor on that engine and you may have put the linkage on incorrectly and now it won't idle down.

With the engine not running make sure when you work the choke lever that the choke opens and closes fully. Make sure when you work the throttle, that the throttle opens and closes fully. If they both do this, your problem is the governor. There should be linkage running from the carb to the engine. It may have a vane operated governor that is moved by the air cooling the engine. As the speed of that air increases, it pushes against the vane. The vane will pull the throttle closed thereby controlling the engine speed.

If not a vane type, then it probably has an internal governor with rotating weights. Regardless of how it is accomplished, I feel that you have incorrectly installed the linkage for the governor, or not reinstalled it at all.

Pics would be welcome.

 

[drnickriviera]

Originally posted by: Zenmervolt

Originally posted by: drnickriviera
Tecumseh is your problem. I'll never go back to a Briggs engine after having Kohler and Kawasaki's

Huh? Tecumseh isn't related to Briggs at all...

And Briggs engines depend entirely on the line; the I/C and Vanguard lines are damn near indestructible; easily a match for anything from Kohler.

ZV

I know that, I just rank Briggs down there with them. I've had an I/C engine, didn't like it either. Vanguards seem nice, but I don't see it on much equipment. If it has a Briggs, it's usually the lowest end one.

 

[Zenmervolt]

Originally posted by: drnickriviera
If it has a Briggs, it's usually the lowest end one.

You're buying the wrong equipment then. Most of the Briggs that I've played with have been Vanguard or I/C; don't think I've seen a low-end Briggs on anything but big-box store junk.

I definitely concede that the low-end Briggs models are junk, but, to be fair, they're sold at a price point where you really can't expect things to be different.

ZV

 

[exdeath]

Fuel injection always seemed simpler and more straight forward to me, probably because I've been programming and working with computers long before I started with cars.

 

[Gillbot]

Originally posted by: spidey07
Gillbot,

I have also struggled with carbs on small engines and am by no means an expert. I felt my man card slipping away. What i've learned is a full disassembly of the carb and soaking in a good solvent will yield good result. By soak I mean at least a two days. Diesel fuel works really well. You can google this. Or better yet look up my thread about 2 years ago regarding this very thing, lots of good help there.

As long as you've got fuel/air/spark/compression and a means to get the gas out (exhaust) you should be fine. Figure out which one is the problem, it may not be the carb.

It is the carb, I used the service manuals to reassemble so I believe I have it right but after speaking with an online small engine troubleshooter he said there are many tips/tricks that you can't explain yet a professional would know. Such as which linkage hole to use when there are many available and why the one the factory recommends may not always be right. What it basically boils down to is my unwillingness to spend money to buy the proper parts and cleaners.

Originally posted by: boomerang
You either had the linkage assembled wrong or the throttle cable incorrectly adjusted. I'm guessing the former. Buy a can of carb cleaner from the auto parts store. Cleaning carburetors with gasoline isn't the hot setup. If you could clean a carb with gas, it would never need cleaning.

There's a governor on that engine and you may have put the linkage on incorrectly and now it won't idle down.

With the engine not running make sure when you work the choke lever that the choke opens and closes fully. Make sure when you work the throttle, that the throttle opens and closes fully. If they both do this, your problem is the governor. There should be linkage running from the carb to the engine. It may have a vane operated governor that is moved by the air cooling the engine. As the speed of that air increases, it pushes against the vane. The vane will pull the throttle closed thereby controlling the engine speed.

If not a vane type, then it probably has an internal governor with rotating weights. Regardless of how it is accomplished, I feel that you have incorrectly installed the linkage for the governor, or not reinstalled it at all.

Pics would be welcome.

I'll try to get pics. I have no doubt something is off or misadjusted but it is not as bad as many would think. I used pictures and the service manual to reassemble so I at least have it close. The problem is as I said above, it's a $100 tractor so why spend $50-100 for repair/replacement parts for it? I already got my money out of it with the times I cut my grass with it. I'm not that worried about getting it running again, but it sure would be nice to but ONLY if I don't have to spend more money on it.

As for cleaning it in gas, it wasn't really a "cleaning" but more of a rinse as it had visible debris in the body of the carb from a non-existant air filter. With the debris in the body, I knew there would likely be debris throughout the carb and when I pulled the bowl, I was correct.

Originally posted by: exdeath
Fuel injection always seemed simpler and more straight forward to me, probably because I've been programming and working with computers long before I started with cars.

I agree, give me FI over this crap anyday.

 

[Kadarin]

Heh.. this thread reminds me that back in the day I used to tear down and rebuild Holley carburetors. Right now that's a completely useless skill...

 

[Gillbot]

Not really, there are many younger kids buying up older cars and they are completely clueless as to what a carburetor is or how it works. Though they may look at you weird when you tell them about dinosaur fuel injection.

 

[Gillbot]

Pouring down rain currently, I;ll try to get some pics tomorrow.

 

[Gillbot]

ok, update. I think the issue is in the linkage.
100_1510.jpg
100_1511.jpg
100_1512.jpg
100_1513.jpg
100_1514.jpg
100_1515.jpg
100_1516.jpg
tvsgov.JPG

After tweaking the governor shaft a little, it will run in low speed fine. As seen from the pics avove and the tvsgov pic, I have that extra spring but WTF is it for. It goes between the linkage for the cable and the stationary governor shaft and does nothing. Also, what links the throttle cable to the throttle blade? I'm guessing this tractor had misadjusted linkages when I got it, I just never noticed. Also, the tvsgov pic does a VERY poor job at showing how all the linkages need to be connected aside from the carb to the governor shaft.

 

[Al010101]

ur such a cheap ass. fly me in...i'll fix it (i could use a break from the 115 degree heat here in hell)

 

[Squisher]

I can't help you, but those are such nice pics I want to make one the background on my desktop

 

[boomerang]

Wow! That's old! They've greatly simplified all that linkage nowadays.

Hook that spring that's sitting there loose in the first of the pics between the throttle lever in pic 100_1514.jpg and the linkage arm with the two adjustment screws. It's shows in tsgov.JPG exactly where it goes.

If you haven't messed with the governor lever on the shaft, and the throttle cable is adjusted correctly, the motor should start, run full throttle, idle down and the whole nine yards.

If it won't, first undo what adjustments you've made to either of those vertical levers. The throttle cable is properly adjusted when the Choke is fully closed when the throttle lever is moved to Choke and the throttle is fully open when the throttle lever is moved to the mowing position.

You're asking about the leftmost vertical lever. I'm assuming it does not move right now. Do the two screws shown there have it bound up preventing it from moving? Does the rightmost vertical lever pivot back and forth? When you move the throttle cable, what linkage moves?

Answer these questions to help me out. I was a lawn mower mechanic in the early seventies, but my recollection is fuzzy. I can't recall if the leftmost or the rightmost lever is the governor to be honest about it.

Answer those questions for me, and I should be able to talk you through this. The pictures are great, but they are loading very slow for me and I do know that's it's nearly impossible to show everything when it's all assembled.

 

[BUTCH1]

Originally posted by: drnickriviera

Originally posted by: Zenmervolt

Originally posted by: drnickriviera
Tecumseh is your problem. I'll never go back to a Briggs engine after having Kohler and Kawasaki's

Huh? Tecumseh isn't related to Briggs at all...

And Briggs engines depend entirely on the line; the I/C and Vanguard lines are damn near indestructible; easily a match for anything from Kohler.

ZV

I know that, I just rank Briggs down there with them. I've had an I/C engine, didn't like it either. Vanguards seem nice, but I don't see it on much equipment. If it has a Briggs, it's usually the lowest end one.

My cheap (Murray) lawnmower with it's cheap (bottom end Tecumseh) engine still runs perfectly after 9 years of use. Engine still has great compression and doesn't use any oil. FL mowers have a long season too, the trick is to just do the maintenance on 'em. I change oil once a month along with air filter wash/re-oil and spray out the deck bottom before putting it away. A lot of mowers (like cars) die a premature death because of lazy owners..

 

[Gillbot]

Originally posted by: boomerang
Wow! That's old! They've greatly simplified all that linkage nowadays.

Hook that spring that's sitting there loose in the first of the pics between the throttle lever in pic 100_1514.jpg and the linkage arm with the two adjustment screws. It's shows in tsgov.JPG exactly where it goes.

If you haven't messed with the governor lever on the shaft, and the throttle cable is adjusted correctly, the motor should start, run full throttle, idle down and the whole nine yards.

If it won't, first undo what adjustments you've made to either of those vertical levers. The throttle cable is properly adjusted when the Choke is fully closed when the throttle lever is moved to Choke and the throttle is fully open when the throttle lever is moved to the mowing position.

You're asking about the leftmost vertical lever. I'm assuming it does not move right now. Do the two screws shown there have it bound up preventing it from moving? Does the rightmost vertical lever pivot back and forth? When you move the throttle cable, what linkage moves?

Answer these questions to help me out. I was a lawn mower mechanic in the early seventies, but my recollection is fuzzy. I can't recall if the leftmost or the rightmost lever is the governor to be honest about it.

Answer those questions for me, and I should be able to talk you through this. The pictures are great, but they are loading very slow for me and I do know that's it's nearly impossible to show everything when it's all assembled.

I have not touched either vertical shaft until today. The leftmost vertical lever doesn't appear to move nor have I ever touched the screws. I plan to attach the spring back on though as I realized after today that's where it needs to go. (That was how I had it for the record though.) I think the governor link is too short and perhaps the leftmost lever is bound up somehow OR the spring isn't the correct spring as when you are in low throttle, it actually folds back onto itself and gets bound up.

I bent the rightmost lever to the left a bit (to compensate for the possibly shorter governor lever) and now it will run and idle with the throttle set to slow but without the spring between the throttle linkage and the leftmost lever, the throttle doesn't do anything obviously.

I need to find out why the leftmost lever doesn't move and IF the spring is the proper one. Unfortunately, the spring I need is apparently a hot item because most places are out of stock on that part and I just found out Tecumseh went out of business and sold off most of it's assets Jan 2009 so parts are becoming scarce.

 

[mooseracing]

Originally posted by: exdeath
Fuel injection always seemed simpler and more straight forward to me, probably because I've been programming and working with computers long before I started with cars.

I've been working on computers since I was 12, I started with carbs at 5 or 6 on my dirt bike. While I agree small engine carbs suck because of the common design that the gaskets have moving parts made to them, they are so stupid simple.

But when you pull one off you need to go through and adjust all the idle/high/low screws to get the proper tune. Screw FI, it it a PITA to troubleshoot let alone to finicky. It's like working on a computer controlled carb.

 

[Gillbot]

Originally posted by: mooseracing

Originally posted by: exdeath
Fuel injection always seemed simpler and more straight forward to me, probably because I've been programming and working with computers long before I started with cars.

I've been working on computers since I was 12, I started with carbs at 5 or 6 on my dirt bike. While I agree small engine carbs suck because of the common design that the gaskets have moving parts made to them, they are so stupid simple.

But when you pull one off you need to go through and adjust all the idle/high/low screws to get the proper tune. Screw FI, it it a PITA to troubleshoot let alone to finicky. It's like working on a computer controlled carb.

There are no adjustments to be made on this carb. That's part of the issue, nothing is adjustable.

 

[Gillbot]

ok, success for the most part. Using pictures i've found online and other parts in the pictures as a scale i adjusted the governor rod on the carb to be closer in length to what the pics show. After setting the throttle to low and forcing the governor to low speed I set the stop screw. I then set the throttle to medium and forced the governor to a medium throttle and tweaked the mixture screw. Then I went to full throttle and set the high speed stop and tweaked the mixture a shade more and it appears to be working ok. I'm sure my lack of knowledge in tuning small engines prevents me from getting this thing to run in tip top shape but hey, I got it running and I cut my grass with it so I say overall it's a win!