Troy Bilt Dies Under Load

[NibbanaFarm]

I have a 28" troy bilt storm tracker snow blower with a 9.5hp tecumseh engine. It is 15 years old. I maintain it perfectly and treat all my 93 octane gas in OPE with Star Tron. Yearly oil changes with M1 5w-30.

During recent use it has been dying under load. I completely disassembled the carb and it was pristine clean. Not a speck of visible dirt. Float needed very small adjustment to bring it to exact level. The carb disassembly had no effect on the problem. It seems to happen after it has been idling. Both times this has happened in the following sequence of events.

I start the machine and use it for 20 minutes or more with no problems. Then I leave it idle for another 20 minutes or so while I go operate other machinery. I then begin using the machine again and after a minute or so it begins to die under load. If I shut the throttle down quickly to idle it will recover and idle without stalling. But returning to full throttle and put under load will cause it to stall.

Any ideas? Thanks in advance.

 

[rdinatal]

Tank not venting properly? The vacuum takes a while to build. Next time crack the cap and see if it continues to run.

-R

 

[leonz]

1. Tank vent in cap

2. crack in coil-runs fine when its cold and when the engine heats up the coil begins to separate

3. collapsed fuel lines -you would not see it as the inner rubber separates from the webbing of the
hose-if they used the good hose that is reinforced

4. crap in tank floats when the engine is at idle and is pulled down when the vacuum of the carburator becomes greater
when the fuel starts flowing and spinning around in the tank.

 

[jaxs]

I agree that tank venting is first thing to check. If cracking and retightening cap after 20 minute idle and starting back to work doesn't help,trash is blocking flow between tank and carburetor. Look for an inline filter and/or screen inside tank.

 

[msb1766]

I had this happen to me on my snowblower, turned out to be the spark plug.

 

[RNeumann]

My guess is the fuel is old- anything over a month or two old and it’s lost some of its BTU’s. That’s assuming the carb is correct as you indicate it is.

The only other LONG SHOT would be something mechanically providing added resistance to the engine- bent shaft, bad bushing or bearing etc.

 

[oldnslo]

Is this electronic ignition or still the old points and confessor system? My vote is something in the ignition circuit is failing. My JD 112 did this years ago and it ended up being the coil was going bad.

 

[Dave M7040]

I have a 28" troy bilt storm tracker snow blower with a 9.5hp tecumseh engine. It is 15 years old. I maintain it perfectly and treat all my 93 octane gas in OPE with Star Tron. Yearly oil changes with M1 5w-30.

During recent use it has been dying under load. I completely disassembled the carb and it was pristine clean. Not a speck of visible dirt. Float needed very small adjustment to bring it to exact level. The carb disassembly had no effect on the problem. It seems to happen after it has been idling. Both times this has happened in the following sequence of events.

I start the machine and use it for 20 minutes or more with no problems. Then I leave it idle for another 20 minutes or so while I go operate other machinery. I then begin using the machine again and after a minute or so it begins to die under load. If I shut the throttle down quickly to idle it will recover and idle without stalling. But returning to full throttle and put under load will cause it to stall.

Any ideas? Thanks in advance.

Carb cleaning means different things to different people.

Most people don't remove and clean the emulsion tube located under the main jet.

The emulsion tube A has tiny holes that should be poked clean with a strand of fine wire.

Chemicals do not get the tiny holes clean nor will blowing air through the main jet.

Removing the main jet requires great care. Find a set of bits for a screwdriver and select the one that is the tightest fit in the main jet slot.

Push down very hard as you try and turn the main jet.

Use the wrong screwdriver bit and you will strip the main jet slot and now in a big mess.

Dave M7040

 

[NibbanaFarm]

Replaced the gas cap and the fuel filter today. If the gas cap is overtightened, it could cause a vacuum. Fuel filter was several years old. Will have to wait for the next storm to test it I guess. New fuel lines on the machine several years ago.

Electronic ignition on this engine. A coil going bad could explain it too I think. Don't know how I would test for this intermittent coil failing other than to swap with a new $60+ part. I've never actually seen a spark plug go bad but a cheap test.

The carb is pretty simple to disassemble completely. Has a plastic venturi that is held in by o-rings and pushes out easily.

Thanks for the help.

 

[Wolfy]

Oh the joys of a Tecumseh :laughing: