View Full Version : 85 S&S engine help

03-06-2007, 10:17 AM
Hey everyone. At the beginning of last year I changed the belts on my 85. Throughout the year i noticed that the Engine area like behind the belts was getting black residue. I know this is a very bad description but it looks like it is building up more as the year went on. Does anyone think that this might be from the belts wearing off? One of my friends thinks that it might be a gasket going bad also. Any ideas? Thanks

03-06-2007, 10:24 AM
Yup, sounds like the belts are wearing. Inspect them- how do they look?

Im guessing you have some misalignment with either the alt or RWP. Take a look from the side and see if everything lines up straight.

03-06-2007, 10:28 AM
Just a thought, but the running surfaces of the belts may have rusted at some point and now those running surfaces are rough and pitted and wearing the belts, the belts could be too tight or the pulleys may be out of alignment. Check everything next time you prepare to run it and spray silicone on the pulley/belt surfaces. If the pulleys are pitted, you may need to replace them. I assume the engine is a PCM, right? Talk to Vince or Richard @ www.skidim.com, 1-803-345-0996, Discount Inboard Marine and see if they have any additional advise to help you answer your concerns.

03-06-2007, 10:31 AM
I get a little bit of the same residue on my 84. I have had the boat for 8 years and I can't recall ever changing belts (maybe once) although I carry spares at all times. If it is like TMC1 says, you might be able to take some light sandpaper and clean up the pulleys.

03-06-2007, 10:39 AM
One of the quirks of the early/mid 80 PCM 351's.

If you look closley you will probobly see a slight misalignemnt of the pulleys.

The new belts will wear to fit the mis alignment, once the belts are "worn in" it wont be so bad.

I wipe my engine off every week or 2 and remove the residue.

03-06-2007, 10:46 AM
Check the alternator i had my 78 doing the same thing and i just added a few washers to level it out... no more belt wear

03-06-2007, 10:51 AM
agreed, it is the alternator bracketthat is usually misaligned. I did the washer thing and it helps some.