engine diagnosis

rosedale123 · Oct 13, 2013

Did a compression check on the MH 30. all cylinders were 105 - so I don't think rings is why it smokes. It starts real easy and runs great - just smokes. The plugs are black and wet - uses some oil.

Could it be valve guides?? If that is it , can valve guides be replace without removing the motor? Does is take special tools?

Do you think this is probably the "culprit" ?

thanks for any and all information.

Jerry/MT · Oct 13, 2013

Does it smoke heavy at idle and clear up a bit at higher rpms? If so it"s likely valve guides. You have to remove the head and press out the old ones and press in the nenew ones.
Otherwise, it"s likely the oil rings are stuck and not clearing the oil off the cylinder wall. Sometimes a couple of ounces of ATF in the cyinders through the spark plug hole can help clean them up.

David G · Oct 14, 2013

I am thinking this is a flat head.

richardinnz · Oct 15, 2013

Your compression test is ok indicating that the compression rings are good, but you may still have trouble with the oil control rings. If the oil rings are just gummed up then a bit of heavy work may put it right.

engine diagnosis

rosedale123

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Jerry/MT

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David G

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richardinnz

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