Engine HRS21 issue

[Mini Motors]

The running speed (Rabbit) is way low. I was mid-lawn when it slowly reduced speed to a sputtering idle. I think I've checked everything. No water in the gas, oil is fine, but changed it to be sure. The spark plug looked dark, so I changed it. I checked the valves(thanks again for those specs, Robert) and they're within specs. When I reach into the linkage, I can fight the governor and it will spin up, but the governor really wants to pull it back down. I popped off the breather cover and looked at the governor assembly, and it looks okay- no obviously broken pieces, and everything moves freely. My only guess is that the governor linkage has somehow slipped out of adjustment. I have absolutely no experience with this governor, so I have no clue how to set it correctly. And if that's not the problem, I'm out of ideas. Help

For those of you unfamiliar with this particular engine, it's an early model, and the flywheel is on the bottom of the motor. A strange bird, to say the least. A friend referred to it as a "half of a motor", because the crank doesn't exit both top and bottom of the crankcase. I think that adds to the lack of weight. I also have a HRT-216 that is a moose compared to it, and considering I have a large 45 degree hill, every ounce is felt helping it up the hill.

 

[DaveTN]

It could be a governor problem, or a fuel starvation problem, or both. The throttle SPRING pulls the engine INTO fuel, the GOVERNOR action pulls the engine OUT of fuel. Somewhere between these two opposing forces results in engine RPM. Sometimes the governor shaft (The part the Arm bolts onto) is not tight against the internal governor shaft arm/plunger and there's slack inside the engine making the Governor Arm not as responsive and performance suffers. When you set the Governor, all you're doing is taking up that slack on the inside so you get full movement on the outside.

 

[Mini Motors]

It's not fuel starvation. The carb and the fuel cap are relatively new(2 years old) and I did make sure all passageways in the carb are clear. Sorry, I forgot to mention this amongst all the other stuff I tried. While I'm at it, I also checked the air filter.

I think I remembered everything now.

I think you're right, that it may be a governor issue. The arm seemed tight on the shaft that exits the crankcase. And since I messed with it, it certainly needs to be set to spec. I figured I couldn't mess it up any worse. I just need to know how. And if that doesn't work, I don't know what to do next.