Replacing Alternator belt on H27 SB8

[Jon Bain]

Anyone replace the alternator belt on the Yanmar SB8 (or SVE8)?I have the Yanmar service manual, and it doesn't seem to talk about how one would adjust or replace the belt (it just says to check the tension periodically)....I assume there is some kind of bolt that allows the alternator to move, but there seem to be several bolts that might fit that description...

 

[Ed Schenck]

Loosen all of the bolts.

On my Yanmar, a 2QM20, any one of the bolts is sufficient to keep the alternator tight. There are two on the mounting feet and one on the slotted bracket. All three have to be loosened and then the alternator can be moved to tighten the belt. I should remove the two at the feet and replace with one long bolt to simplify.

 

[Blume]

Replacing Alernator belt

I adjusted mine last weekend for the first time and it was a little more difficult that it looked. there is a pivot bolt on top left you have to loosen the the adjustment bolt on the right you have to loosen not only on the front but back. I didn't do a replacement, but have a spare just in case. I think when replacing you might have to remove the protective cover. A really big screw driver or small pry bar will help with getting the right tension on the belt.I could tell mine was slipping because of the black 'dust' in the engine area.