Broke two V-belts - Page 3 - SailNet Community
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post #21 of 25 Old 06-03-2019
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Re: Broke two V-belts

Insure that the bolt that holds the alternator dosent have misplaced washer/spacerwhich moves it forwd or aft a bit
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post #22 of 25 Old 06-03-2019 Thread Starter
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Re: Broke two V-belts

I was hoping there would be a small spacer that could be adjusted, (it would have to be a thin washer and as mentioned that would only line up the outside of the pulleys) but there is none.

However, this time my "new" spare belt will keep its Yanmar line code label so I know it is a new one!

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post #23 of 25 Old 06-03-2019
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Re: Broke two V-belts

"The install does not look to bad, but probably requires an impact wrench to remove the alternator pulley."
We had a similar problem changing a pulley. Took the alternator to a local gas station, told the mechanic "This is from a boat, not a car. We couldn't bring the whole boat in, but could you swap out this pulley?"
I don't remember if he asked $5 or $10 but it was way simpler than buying an impact wrench.(G)
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post #24 of 25 Old 06-05-2019
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Re: Broke two V-belts

I have a 3GM30 as well, with a 120a alternator.

I use Dayco TopCog belts, long enough not to be forced on, yet can be tensioned sufficiently.

You (or someone) mentioned Kevlar belts. Don't! At least w/o checking the specs. There is a minimum sheave diameter that can be used without damaging the belts. I learned this after ruining two belts in quick succession. They went slack in a matter of hours. The non-stretch Kevlar on the perimeter forces the rubber at the bottom of a small sheave to be compressed more than it can handle.
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post #25 of 25 Old 06-06-2019 Thread Starter
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Re: Broke two V-belts

thanks for that info. I have decided to use the OEM belts for now.
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