Question for you small engine mechanics.

[BIG BLACK WARRIOR]

I have a snowblower with a 10 HP tecumsch engine on it. I had a problem part way through last winter with it stalling out. It starts fine and runs good for about 5-10 minutes, but then it wants to stall. It I put the choke on 1/2 it will run for about 5 minutes more then wants to stall again. Then I put the choke on 3/4 and it will run for another 3 or 4 minutes, and want to stall. I then put the choke on Full and it will run for about 3 or 4 minutes, then stall out completly. I then will have to wait about 1 hour for it to cool off, then it will start, and I will have to go through that whole sequence again. Any ideas what my trouble could be. The carb is clean and seems to be working OK. Could it be the stator? Thanks for any ideas.

 

[kyzer]

Carb problem... Might need a carb kit, but sounds like the carb needs to be taken apart and cleaned, you should adjust the float while your at it.. Lust my opinion..Good Luck..I have had the same problem with my snowblower, it would only run on half choke..

 

[ROCKERDAN]

check the fuel filter or replace it,sounds like its not getting fuel delivery.

Dan

 

[grizztracks]

check to see if it has an oil pressure sensor. I've had similar problems on small generator engines. If there is one you can bypass it to see if it cures the problem.

 

[apltx08]

check to see if it has an oil pressure sensor. I've had similar problems on small generator engines. If there is one you can bypass it to see if it cures the problem.

No these engines get oiled with whats called a DIPPER mounted on the connecting rod cap and as it turns splashes oil, so their isn't any oil pressure sender unit...as mentioned your 1st thing to check is FUEL delivery, hoses, shut off valve, filter if any, bottom of fuel tank for any GOOK build up, take carb appart and check all JETS to be free of VARNISH/GOOK build up, once you get that done test it out, then its a process of elimination, it could also be your FIRE...coil, some tend to short when they get wet & hot and start ARCING, spark plug wire cracked and ARCING, to check for any arcing start it up in a DARK area and use an empty container of WINDEX or whatever fill it with water and mist engine around the spark plug area and follow wire down to COIL and look for any ARCING/SPARKS, last thing is check your STATOR'S output...

 

[kinger]

I have the exact same thing on a 5hp Briggs for my pressure washer. I put a carb kit in and no change. I'll be damned if I can figure it out. I have spark so it must be a fuel issue, I'll take it apart again and drain the tank and wash it out with carb cleaner and see if I just have some goop in it.

Is the gas fresh or old and stabilized?

 

[brian m]

stall out

Might sound crazy but I had this kind of problem on my lawn mower and it was the gas cap was not venting properly and it would starve for fuel. New cap and no probs since.

 

[ahicks]

If you've put a kit in it and it's still starving, have you tried loosening the gas cap to check if the vent is plugged? Or in the case of the setups that require a fuel pump because the tank is too low to gravity feed, or for that matter even a gravity system, have you checked fuel delivery to the carb?

Is there a sediment/crap trap someplace in the system? Maybe it's full of water?

 

[grizztracks]

My mistake, I was referring to a low oil sensor not a pressure sensors. I know that the 10 HP Tecumseh engine installed in some generators ran low oil sensors and I've seen them fail.

I have a hard time believing its a fuel problem because it starts and runs fine when cold but you may want to make sure the fuel tank is venting (just remove the fill cap).

If it quits and won't start again give it a spray of starting fluid (don't over do it). If it starts on the fluid then it probably is a fuel problem. If it still doesn't start check for spark, If no spark check the coil pulse, coil primary and secondary resistances, all wires/switches and stator.

 

[RedRocket]

If you have to choke it to get it to run when warm then it is not getting enough fuel. Start with the tank and make sure everything is clean all the way to the engine. Empty the tank and clean it, replace the fuel filter, clean the carb and make sure the pilot screw is set properly (if you don't know the stock setting use 2.5 turns out from lightly seated), and check that float in the bowl moves up and down freely and shuts the jet when up.

The choke has no effect on spark, if a weak spark was the problem then it would be harder to start with the choke on.

 

[BIG BLACK WARRIOR]

Thanks for all the advice. Gas cap vent is open. I have cleaned out the Gas tank. Fresh plug. Have taken carb apart 3 times. All jetting is set properly. I tend to think it is either the coil or the stator.

 

[woolyviper]

common problems with small motors are - dirty carbs, loose fasteners holding the carb to the block, i suspect you have debris in the carb and it's getting pulled into a main or pilot jet - the choke keeps it running as it corrects the fuel air mixture - if you have the rubber fuel lines, i've seen them get soft and collapse - the electrical in these motors tend to be good or bad, not intermittent.

 

[SlowPoke]

If you had your carb apart did you replace the little rubber float needle seat? If it is worn or missing the motor will run fine for a few minutes then flood itself out. It is a VERY commenly overlooked part on these carbs because most DIYer's don't know it is in there and is very small. I had one guy who worked on his carb himself and used compressed air to blow out the passages and ended up blowing the seat right out. New float needle and seat and it was good to go.

But I agree it is most likely a fuel delivery problem.
Try running it till it stalls out again, then immeadiatly shut off the fuel valve and pull the float bowl, see if there is gas in it.

Good luck, and better hurry snow will be here before you know it.

 

[sgilbert]

dito. 100% the oring seat is swelled from leaving ethonal gas in it. see several a year. sheet rock screw gets it out, push new one in with back side of drill bit. correct side up, should acheive level float

 

[04JRB]

Ugh, I went through this in the spring with my riding mower. It seems Tecumseh is plagued by some really maintence freindly duds in their carbuerators. Mine gave the hunting/surging symptoms, even after the rebuilding process. The carb I had was "not available" on the rebuild list. Believe it or not, it was a "throwaway" carb, prone to issues, and its easier to replace than clean. something about bonding plastic to metal an them not being meant to take apart easily. well, not while trying to put it back together in mind.

after screwing with the stupid thing all winter, lol, it just had a design flaw that couldnt be fixed/cleaned. $80 carb, runs like a top. But, it looks like the fix is to replace and/or clean thoroughly every fall.

not really exactly the OP's issue, but related. Tecumseh does have some info on the internet if you look, Ill see if I can remember the site I got the service manual download or something.

Here: not troubleshooting, but some exlploded views never hurt.

http://www.partstree.com/parts/?lc=tecumseh

Google can help find which engine you have, or the serial late somewhere on your block.