Wisconsin VH4D

Ac145 · May 16, 2022

On my stump grinder. Over the last 30 years three rebuilds. Hit the starter, three revolutions starts right up and go out and grind stumps. So the problem Im having is it appears to be running way too rich. Put my finger and wipe on the exhaust pipe a lot of black soot. Yesterday check the timing all is good. Took PB blaster brake cleaner which is Volatile ,how I know that is I sprayed some on the bench and it burned. While its running sprayed all the manifold gaskets no change in RPM until I sprayed the throttle shaft linkage and then got some noticeable difference so I have a leak there. Could the oil bath filter element be so plugged up causing it to suck more fuel than air..

J.Wondergem · May 16, 2022

That seems to me that would be the first place to check for running rich. It seems the throttle shaft seal leak would made it run a little lean.

Steve@Advance · May 16, 2022

Generally, a partially clogged air cleaner will not make one rich, as long as the carb is right. But by all means service it! There is a wire mesh inside the canister, it is often overlooked and packed with dirt.

A slight vacuum leak around the throttle shaft is common. Unless it is excessively worn it generally is not a problem. It can cause idle problems, but I doubt you need an accurate idle on that application.

What will richen one up is:

Clogged internal air bleed jet.

Loose main jet.

Main adjustment screw backed out (if equipped).

High float level, partially sunk float, trash holding the needle valve open, bad needle/seat seal, loose needle valve seat, pressurized gas tank, too much fuel pressure (usually when an electric pump has been installed).

Choke failing to fully open.

Any of these can also contaminate the oil with gas. The engine will breathe in gas vapor from the crankcase vent, causing a rich mixture. Plus the possible engine damage from diluted oil!

Roger in Iowa · May 16, 2022

Don't run it too lean. I believe being on the rich side helps with cooling of the engine. Is it showing black smoke when running? The soot may be normal.

rustred · May 16, 2022

pull out the spark plugs and look them over. see if all 4 are black or what? those engines dont run rich. plus known for hard on valves. might to check your carb float, that will do it. darn near every machinery dealer had them on swathers in the 1970's.

used red MN · May 16, 2022

I am not sure what it takes to remove the wire mesh in the oil bath air cleaner, I know in Farmalls you basically have to cut out some of the support members to remove it. Before I would condemn the oil bath filter I would have to disconnect the air cleaner from the carb and give it a test run. This should prove if the air cleaner needs the wire screening cleaned or not.

herk · May 17, 2022

Hello years ago my dad had a R jd that we took the oil bath air cleaner off and put it in a small fire , I remember that when it had cooled he taped it on a wood block and it was unbelievable how much burnt dust feel out , I think he rinsed it with gas before he put it back on, Bryan

Wisconsin VH4D

Ac145

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J.Wondergem

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Steve@Advance

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Roger in Iowa

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rustred

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used red MN

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herk

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