Problems With Idling-Tecumseh 6HP OHV

[Kawabuggy]

As the title says, my kids go-cart will not idle. We can get it to run, but you have to have someone stand on the gas while pulling the starter rope. Then the engine fires and runs. As soon as you let off the gas-DEAD. I pulled the carb off, and took it apart-floats, float bowl, and needle (as part of float assembly). It looks like the main bolt that passes through the center of the float bowl, that holds the float bowl to the carb is the main jet. Is there a pilot jet on these carbs? I cleaned the carb out as best I could with compressed air, and a can of carb cleaner. Same thing after reassembly. If it matters, I just readjusted the valves, and put a new spark plug in to be sure those were not the problem.

It does not burn oil, no weird colored smoke from the exhaust when it runs.. It just WILL NOT idle.

Any ideas? If I can't figure this out, I'll be buying a new engine. I was thinking about doing a compression test just to see where the engine is at. Is it possible to get a true reading on these engines doing a compression test, or does the compression release system give false readings?

Any help would be greatly appreciated.

 

[kendelrk]

dont go to the extent of the new engine, heres what you need to do, again pull the carb off, you missed somthing tiny, dis assemble it completely, nothing more you can take apart, boil it for about 30 minutes in lemon juice, then when you take it out, spray it with some wd-40/carb cleaner, now take a wire brush and take out one bristle, theres small holes in the main jet, be sure to poke every one of thesse out, im not sure on valve adjustment, but is it an adjustable carb? if do you might need to re adjust, if not you missed a small spec of dirt thats going to piss you off, does this engine have a choke or primer bulb?

 

[Kawabuggy]

Yes, this carb has the primer bulb. NO it is not adjustable. I've just done a Google search on "Tecumseh engine won't idle" and it appears that I am one of the MILLIONS of people experiencing the same problem. Unfortunately, of the 50 or so posts I've already read, no one has ANY KIND OF IDEA as to what to do to fix it.

Kendelrk, I'll take your advise as it sounds like the idle circuit may be plugged. I would think it would be running lean if the idle circuit were plugged though. Even after an engine comes off the idle circuit, and starts running on the main circuit, shouldn't the idle circuit still be contributing a little bit of fuel....?

When you say boil it in lemon juice, do you mean to literally submerge the carb body in L/J and then boil it on a stove...? just want to be sure about that as if the carb has plastic or rubber parts inside that are not serviceable, I don't want to melt them.. I'll follow your advise as I have nothing to lose.. If it works, great! If not, this motor is off to the scrap-yard in the sky and I'll replace it with a HF Honda clone engine and be done with it.

 

[Russ2251]

Hmm...
Can't fix it, buy a clone.
What happens when the clone exhibits the same problem?
There is a good chance that sooner or later it will.

 

[kendelrk]

once the engine is set back to idle, the throttle butterfly closes and runs off of the idle jet letting only so much gas through, plugged, you get no gas and no idle, and our friend who seems not to be with us anymore wrote us a guide to boiling in lemon juice, ill give you that link, andeven tho i am one of the people who have had enough clones in thier lifetime, i suggest the tecumseh. american made, more power, more power/weight ratio, those hf clones are good, but the parts arent of the same strength, it sounds stupid right now, but with the carb on, see if holding the primer bulb in makes a diffrence, ive never really played the prime carbs, but i have heard holding in the bulb makes a diffrence somehow, to some people, try the lemon juice method, i also have another question, lets say your in the kart, if you keep the throttle depressed is it fine until it reaches a certain point on the butterfly? if so it could be your carb, or your head gasket, i had a tecumseh that had just a little blow out and it wouldnt run unless it was full throttle, also was a pain in the *** to get running, but heres the write up, the carb is a cheap clean, and so is the head gasket, if its not either of those, its an air leak, i can tell its either a carb or head gasket thing, heres the link to lemon juice http://diygokarts.com/vb/showthread.php?t=11976&highlight=lemon+juice , the way i did mine was i took all rubber peices out, leaving only metal/springs from the carb, put it in a tall pot of lemon juice and boil for 30 minutes, be careful tho, it smells really bad and your mom/wife could get mad, now take it out, and poke everything out with a peice of the brush, if this dosent do anything, put it against a wall and see if someone can get it running, now get a can of carb cleaner, get it started and park it against a wall, have someone keep it running, tell them to let off the gas and when they do spray carb cleaner around the carb mounthing places and gaskets, if the engine revs up or runs longer without dieing its leaking air and you must replace your gaskets, if its still not idling,dosent leak air, and you have nothing to turn to, go get a 3 dollar head gasket and that should take care of it, the cost totally to fix this is about what. 6-10 dollars? much better than 130, and tecumseh will have more power and better parts, our friend russ2251 is a big tecumseh fan

 

[buckeye]

There are great youtube vids on carb cleaning. Also, I meesed with a 3.5 tec, nonadjustable carb and just couldn't get it to idle for crap. Take apart clean put back on, take apart over and over. Finally bought a adjustable carb. Best 39.95 I have spent. This runs perfect.

 

[kendelrk]

my first engine was a tec flathead 3.5, we seriously spend 109$ on a new carb, and then it gave me problems one week in, those carbs were terrible for getting dirty, but then again, i didnt use a fuel filter

 

[Kawabuggy]

Buckeye, can I get a link to where I can buy a replacement carb? I'll try the boiling in lemon juice first, but if it does not work out, I'd be willing to dump another $39 into this engine before scrapping it.

Also, Kendelrk, where might I be able to purchase a head gasket locally? I'm in the Houston, TX market. Do I need to order over the net, and let them ship it...? Or, can something like this be found in a Sears, or Home Depot?

One last question... If/when I get this engine running right I need to think about a way to make more power. It only runs to about 30MPH right now. This cart DOES NOT HAVE a torque converter, or jack-shaft arrangement. The engine direct drives the sprocket by way of a toothed clutch. If I wanted to put a torque converter on it, along with a live axle, and bigger rear tires, where might I be able to pick up a used converter set, and/or jack-shaft set up? I hear a lot about the Comet 30 series.. On average, what would something like that run? I already have a live axle set up from another cart that was scrapped.

 

[Russ2251]

See troubleshooting charts.

 

[Kawabuggy]

Kendelrk, again you are opening my eyes to my potential problem--FUEL FILTER! This cart does not have one on it! I'll be sure and pick a new filter up tomorrow while before I put the carb back on after boiling it. Would have to have to do this repeatedly.

 

[kendelrk]

you can pick up a head gasket cheap at your local mower shop, gearing is a way for more speed, but youd get less acceleration, a comet torque converter is around 200 dollars for genuine one, and youd need a comet 30 or equivlent, youd need diffrent tires, bearing hangers and practically a life axle conversion kit,30mph is decent, if your looking for a little more, gearing or torque converter is the best way to go
edit: id suggest a fuel filter, good way to go, you can pick that up at a mower shop to

 

[Russ2251]

What is engine model number? Does it look identical to this?

 

[Kawabuggy]

Yes, the engine looks similar to that. The ONLY difference I can tell would be instead of having a red sliding switch for carb control like the engine pictured has, it has a simple on/off switch that you flip.

I'll check with my mower shop for both a head gasket, and a carb kit. I cleaned/reused everything the first time I tore the carb down, but it would not hurt to replace all that stuff.

I viewed the carb cleaning section on the link that russ2251 linked to. I did not realize I could disassemble further than I did previously. I'll pull it all back apart tomorrow, and tear down further than I did before, and then boil everything in lemon juice. Hopefully I can find a "mower shop" local to me that will have parts in stock.

 

[Kawabuggy]

Oh and THANKS to everyone that has taken time to respond! I promise I'll post back and let you guys know how it all goes. I hate when people ask questions, and then never post back to let you know whether your advise worked or not, or what really was the problem. I'll follow up with you guys to let you know what the deal is with this old, tired, beast of a cart.

 

[buckeye]

Pats small engine parts will have everything you need. Thats where my carb came from. Not a lick of problem.

 

[Russ2251]

As a side note:
Although I have not tried this lemon juice thing (no need to) as yet...I am a little leery of it.
Citric acid is an etchant which means it has the ability to destroy.
Finely machined needles or holes cold be adversely affected.
My 2¢.

 

[kendelrk]

as i beleive lemon juice is barley acidic, but its still there, its lemon juice we use in cooking, some even drink it, it makes them spotless because the small amount of acid eats everything away, the reason we still poke it out with a wire brush is incase theres somthing still in those holes, ive lemon juiced a clone carb, a briggs carb, and a tecumseh carb for a few neighbors, there mowers and my clone had still held up no problem, i dont think it really hurts, but i could be wrong

 

[buckeye]

I have heard of the juice trick. The way I remember it, was for really old nasty corroded carb. To me nothing beats patience, good carb cleaned, fine wire(bread twisty tie works or speaker wire) and good set of brushes. And in my case, good reading magnifying glasses. Really be sure to get all the small holes on the jet. There is one about half way up the threads that is angled. Easy to miss.

 

[Russ2251]

Could not agree more!!! I use an eye loupe.

.

 

[Kawabuggy]

Very good information.