high pitch squeeling

[dan161]

I have a 90 marathon that has a high pitch squeeling coming from I think the fan on the side of the motor. I thought maybe it was the brakes, but I jacked it up and ran both rear tires individually and it didn't make a difference either way. I tried spraying carb/brake cleaner in and around the fan but it didn't make a difference either. Short of taking the shroud off around the fand and removing the fan does anybody have any ideas. Also right in the center of the shroud where the shaft is it looks like there is supposed to be a cover that is screwed on with 2 screws. Is it critical or not that this be on as I'm missing mine. Thanks in advance
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[redcloud]

The holes are for the oil injection pump that seems to be missing on yours. Are you putting oil in your gas? If not, you may be hearing a dry crank bearing. Just a thought as not much else than can give you a squeel on that side.
I take it the squeel is related in pitch of the engine rpm's?

[dan161]

yes I mix my oil in the gas. All the oil injection stuff is missing. The squeeling is related to certain rpms. Seems to be more apparent at lower rpms like when your going slowly or coming to a stop and letting engine idle down.

[redcloud]

Are you sure you have all belts tight and they are not warn? Starter/gen belt could be doing this if it is old and warn out/stretched.
Is your fuel/oil mix at 128/1 or more? also, do you mix your oil/gas before you put it in your tank? If you pour oil into the gas tank it will not mix well and you can be leaning the engine out of oil and giveing a bearing/engine dry squeel. Just some more to think about as you join us all trying to figure out one of the simplest engines in the world. Sometimes I think it is easeir to find a problem with my 7.3 tubo power stroke.

[dan161]

No kidding. I mix before putting in fuel tank at 100:1. Drive belt is brand new and the starter belt is older but is very tight. Guess I could try new starter belt tho. It's relatively cheap and won't hurt anything.