Outdoor Power Equipment and Small Engines - HM80 engine

The HM80 engine on my generator will only run with full choke and then it coughs and backfires. I took it to a local shop and they told me it either had a bad carb or governer troubles. I saw a thread that mentioned a gear on the governer possibly being a problem. I opened up the crankcase and checked it and it appeared fine. I don't know how to adjust the linkage properly. I bought the Tecumseh technicians handbook and saw their recommended procedure., which probably makes sense to a small engine mechanic. 4 of the items they refer to for an adjustment aren't labeled or pictured in the diagram they ask you to look at?????? I'm interested in knowing how to adjust it properly, and also how to rule out the carb as being the problem.

You most likely have clogging in your carb. Clean your carb really really well! Then let us know how it goes.

Hello draperjojo!

You have a carb problem. Don't adjust or loosen any of the governor settings. They don't get out of adjustment, and if they were, it wouldn't cause the problem you describe. Remove the carb and clean it out. You may be able to get it going by just removing the bowl and clean it out and the bolt that holds the bowl on. It has tiny holes in it that need to be clear.

Cheese, your'e right. I changed the carb to another and it fired right up. I adjusted the screw on the bottom and it started running smooth. Now the rpm's started creeping up to a level I didn't think was good so I shut it down......now back to the correct adjustment on the governor....how do you do it in layman terms????? If I can get the thing adjusted correctly I think I'll be done. Help!!! When I changed the carb I put in fresh gas,a fuel shut off valve, inline filter and a new air filter, oh yeah, and a wheel kit for the generator.

Ah...NOW it sounds like a governor problem, but first check to be sure the throttle shaft is not sticking. Make sure it moves easily from open to closed. (the actual shaft in the carb).

There should be a small hex head screw in the governor arm coming from the engine. It has a slot for a flat head screwdriver. It holds the governor lever (long piece with the holes for the wire linkage to the carb) to the governor arm (short piece that is clamped to the shaft coming out of the engine. Pull the governor arm away from the carburetor as far as it will go, and while holding it there, move the lever until the carb is at wide open throttle. While both pieces are at this position, tighten the screw. This should get it set right. Has someone already moved it? When a governor is set from the factory, it should never need setting again.

Now that makes sense to me....I'll try it,thanks so much!!!!!