The 9.2 Cal that I bought with a 2GM20 had black dust all over the front of the engine. I spent a couple hrs cleaning the engine and compartment and then replaced the alternator belt with a top cog belt from the local car parts store. 55 amp alt...It has worked well, no new black dust, for over 5yrs. The old belt had worn thin and was slipping in the pullies. The small raw water pump
belt did not have an equivilent, so I had to order a Yanmar belt.