View Full Version : Engine struggling under load


Bob DiGiacomo
01-18-2009, 12:57 PM
This snowblower is driving me nuts:cry: I thought the carb was working fine, but 2 things are happening (now that I have it running in the snow). It doesn't have the power to throw the snow far and the engine is struggling when the auger is on and it is clearing snow. Should I have removed the welch plugs on the carb when I cleaned it the first time? It is a tecumseh carb. Please Help. Thanks

pyro_maniac69
01-18-2009, 01:28 PM
are there adjustments on the carb?

if so, bring out the low idle screw (on the side of the carb) out about a 1/8 of a turn and try it

Bob DiGiacomo
01-18-2009, 01:59 PM
There are no adjustments. There was a capped screw that I found. I took that out when I cleaned the carb and then I put it back. The screw was seated, so that is where it is now.

bser
01-18-2009, 02:28 PM
Besides carb ,check your auger belt(s) With the EPA rules we also inherited none adjustable carbs.

Bob DiGiacomo
01-18-2009, 02:43 PM
Bser,

I think that the belt is loose or slightly stretched on the auger, but the engine is not running well under load, so I wan't to get the engine going before I get working on the belts. The auger seems to be turning freely and is not binding.

bser
01-18-2009, 03:03 PM
Is spark plug new? If you have cleaned carb it should run ok hopefully.Sometimes with these new EPA carbs it's best to replace the carb, then spending alot of time trying to fix them at $40-50 an hour.

Bob DiGiacomo
01-18-2009, 03:11 PM
I could try a new spark plug, but I am pretty sure the one I have is good. I don't mind spending the time to try to fix it. I'm not paying anyone this is a DIY project. I didn't remove the welch plugs is that a problem?

30yearTech
01-18-2009, 08:00 PM
I could try a new spark plug, but I am pretty sure the one I have is good. I don't mind spending the time to try to fix it. I'm not paying anyone this is a DIY project. I didn't remove the welch plugs is that a problem?

There is an outside possibility that there may be some debris under the welch plug on the side of the carburetor, this one covers the low speed and transition orifices for the low speed circuit. This will generally only affect acceleration and Idle, as the load or high speed circuit is fed from the bottom straight up the nozzle. The welch plug that's inside the carburetor, just covers the bowl vent.

I would re-check the float bowl nut and nozzle for any restriction. You may also want to check the mechanical operation of the blower and make sure that all is free and nothing is binding and just putting too much load on the engine.

Bob DiGiacomo
01-24-2009, 06:47 AM
After talking with 30yeartech I got the problem solved. Turned out that I had low compression. I picked up a compression gauge after talking with 30yeartech and found the compression to be 60 PSI. I lapped the valves by hand and ground the valve stems and that brought the compression up to 112 PSI. That made all the difference. Turned out that the carb was not the problem. I found several really good small engine instructional videos on youtube.com created by davidsfarm that took me through all the steps of lapping the valves. Thanks for everyone's help on this one. Only problem left is that it is not throwing snow more than 3 feet (but the engine is not bogging down), I think it needs a new belt although the old does not appear to be slipping? Suggestions welcome.

30yearTech
01-24-2009, 12:01 PM
I found several really good small engine instructional videos on youtube.com created by davidsfarm that took me through all the steps of lapping the valves.

I have looked at a few of his videos and most have basic good info, but don't follow the one on adjusting governors, as he is way of base with the info in that video!

Bob DiGiacomo
01-25-2009, 08:25 AM
I made an adjustment to the belt and now it throws snow about 12 foot; good enough for my driveway. Thanks for all the help. Bob