What is causing my alternator belt to produce a black powdery dust when the engine is running?

sustutt · Newbie

What is causing my alternator belt to produce a black powdery dust when the engine is running?

my1972ih · Member

An old brittle belt could do it, but I suspect either
1. improper belt for the pulleys on the engine or
2, alternator pulley not aligned with drive pulley/ pump pulley, etc.

sustutt · Newbie

Thanks for your suggestions. Do you know how difficult it would be to do a realignment, if that is the problem?

my1972ih · Member

It usually depends on how much adjustment is available in the alternator mount. If you lay a straight edge across the pulleys you'll probably be able to see if they are aligned. Assuming adjustability, ease tension on belt, loosen mounting bolts on alternator, align, re-tighten everything. I would recommend checking with info@betamarinenc.com they are very helpful and will probably have recommendations. You never said how old the engine is, just that it has low hours. Also, does the inside of the belt show any tiny cracks or little chunks missing? Are the groves on the alternator pulley exactly the same as the grooves on the other pulleys? Is the belt an exact match for the pulleys?

sustutt · Newbie

Thanks. The engine is a 2009 I believe. I plan to call Beta tomorrow, Monday/ 1/5. They were closed Friday for holidays. Before I have mechanic come out, I would like to consult with Beta. Good advice. Hope this isn't too big a problem.

my1972ih · Member

given the new info, my bet is old belt. figure that it is at least 5, maybe 6 years old and has spent most of that time stiffening up in one position. You'll probably be in touch with Stanley. We bought a new Beta Marine 38 about 3 years ago. had an alternator drive pulley problem which they handled. Reggie. SV "Submit"