Originally Posted by rjc9136quinn
I have a Yanmar 2gm20 F with just under 300 hours. My fan belt is fraying into a fine ,fluffy powder. I lost a belt in Vineyard Sound in August and the replacement is fraying in the same manner. I have tried tightening and loosening, both to no avail. Pulleys appear to be in line and no play in the sheaves.
I'm running out of ideas to try for what seems to be a rather simple problem.
If anyone else has had a similar problem and solved it I would love to read the solution.
I assume you mean the alternator belt?
Are you running a stock Hitachi alternator, or have you upgraded to a high-output alternator?
If you're running a high-output alternator, the stock belts just aren't up to the loads and tend to wear quickly. You normally need to use a special heavy duty belt like a Gates Green Stripe.
If it's just the stock alternator, have you had any indication that the bearings in the alternator are binding up? Noise, resistance, lower output, etc?