Barely running HH80...

[JBsDeere 0]

This thing has gotten on my last nerve. I have gone over the whole fuel system, it seems to be delivering fine. It's getting strong spark also. But...It still only will start at full choke and full throttle. Will continue to hunt and stumble at full throttle and choke OFF. If i hold the governor in a fixed position it will run fine.

I uploaded a video to youtube of me running the tractor and messing with the governor and carb.

Does this mean my governor is shot?

Also, the Electric PTO clutch let off a massive spark and will now not engage. How much am I looking at spending to fix this thing?

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[Horse-Drawn 1]

Hi there...

Watched your video... Read your post.

Has this always ran this way? What was going on when it started / before it started?

The symptoms say it's running lean. If you haven't messed with the gov., then either the fuel pump is very weak, or more likely, the carb is not adjusted right.

I would go through the initial carb setup and see if it fixes it.

[JBsDeere 0]

I rebuilt the carb and tested the fuel pump. I have adjusted the high/low idle mixtures. If i add fuel it bogs. If i trim fuel it stalls.

It ran great for 2 hours mowing some decently thick grass. then it slowed and stalled. Been doing this ever since. I never touched the governor arm or springs.

New air filter, fuel filter, emptied and cleaned tank, rebuilt carb, new spark plug...

And to top it off the PTO died. :wh:

[puddlejumper 67]

Does it run fine with the governor held in any position or just wide open?

And when you rebuilt the carb did you soak it and blowout all the passages with air. Are we absolutely without a doubt SURE that the carb is clean.

[tunahead72 2,346]

How about the throttle shaft that goes into the top of the carburetor? Can you wiggle that back and forth at all? If it's loose, it'll cause all sorts of problems -- the carb will seem to adjust itself, and if you make any changes to the settings, the engine response won't make any sense at all.

Just a thought, based on an earlier experience of mine ... there are shaft repair kits available, they're not expensive and they work well.

[JBsDeere 0]

It runs well at about half to full throttle when held. It doesn't want to run at low idle.

I am fairly certain the carb passages are clean, I blew it out, checked the float for leaks, etc. I did not soak it in anything. What is recommended for soaking?

I haven't noticed any play in the throttle shaft but I'll look again.

[puddlejumper 67]

Get a gallon of chem dip and follow instructions it can be used over and over for parts cleaning. It really sounds like a Air leak if your sure the carb is clean.Throttle shaft as mentioned above.Or bad carb mounting gasket. You did use a new gasket didnt you. If you have not caught on to my line of thinking there are no shortcuts You may get lucky once in awhile but eventually it will bite you in the butt.

[JBsDeere 0]

Yes. All new gaskets were used. I'll see if soaking helps anything.

Thanks for the help :thumbs:

[puddlejumper 67]

After you rebuild the carb again if you still have problems.You may read brian millers carb page thats pinned at the top of the engines section. He tells how to set your govenor. I doubt that is your problem but a little reading on that page may click something in your thinking process :thumbs:

[shorts 182]

when was the last time you checked the points? :thumbs:

[tunahead72 2,346]

It really sounds like a Air leak if your sure the carb is clean.Throttle shaft as mentioned above.Or bad carb mounting gasket.

puddlejumper -- Is this something he can check with WD40 -- Engine running, spray WD40 (or something similar) around these areas, any change in how she runs indicates an air leak there?

And JBsDeere -- Bolts attaching carb to engine nice and tight?

[puddlejumper 67]

Yes he cvan spray carb cleaner around the areas and see if there is any change in engine to detect a leak. Just do not confuse yourself by letting spray mist into mouth of carb

[JBsDeere 0]

when was the last time you checked the points?

There are no points on an HH80 Techy. It's a solid-state ignition.

Bolts from carb to head are tight. I will try checking for leaks. But it strikes me as very odd that it ran great for 2 hours before it had issues. :wh:

[puddlejumper 67]

You might try to retorgue the head. It is possible the leak is in your head gasket or valves. But I dont think I would remove it untill you soak and redo the carb. That will probably be next. KISS (keep it simple stupid)

[Horse-Drawn 1]

This may sound like a weird question... But, When it's "hunting", is there any color to the exhaust? Like black smoke?

If no, try opening (counter-clockwise) up the main 1 full turn. I've had some engines in the past that defied logic & preferred to be 1-2 turns richer than you'd think or than the book says. Especially engines that were bored out .020 or more.

...Just a thought :thumbs:

[JBsDeere 0]

No smoke. I tried richening and leaning the mix and it sputters. too rich will puff dark smoke. leaner will just want to stall. Next time I'm working with it I will check carb again for leaks and debris.

Since it has good compression it's gotta be something simple...

[puddlejumper 67]

Another thought thats a simple check and possibility. Check your flywheel and key it could have been a little loose and cut or partially cut the key thus causing the engine to be out of time, it can still run but not run well.