Yanmar 1GM10 with loose fanbelt , how much play should there be ?

[charles_reed]

I didn't even start the video because I could see from the still that the belt was much too loose! Some of the posts on here really worry me. If someone has to video a problem and ask for advice what are they going to do in a real incident? Read the manual, think what may go wrong, check before you go out. If you aren't practical get / pay someone else to sort it out or show you how to. In fairness, perhaps that is exactly what the OP is doing but I do wonder sometimes!

You may be under-estimating the cunning of the poster - you'll get an auto-redirect to another U-Tube clip, this time an advert for a patent Yanmar belt adjuster.

 

[charles_reed]

Where do you source an improved pulley? This sounds like a good idea.

They're made out of solid - I always have one with me - cost nothing off an old alternator. Don't forget it's a LH thread.
The one Lakesailor has shown is designed for a 13mm belt - there are 14mm and 17mm, in addition to various strange US dimensions,
A big alternator >90 amps, charging seriously discharged batteries (especially through an external smart controller) needs a taut belt. For that reason I suspect RichardS's experience is limited.
Moreover modern alternators (>2008) such as the Iskia aftermarket ones, make external "smart" controllers totally redundant. Mine satrs @ 15.1v and soon drops off to about 14.1 and then gives a float of 13.8.
The highest voltage which I've seen, with the Adverc in circuit was 16.1v and climbing.
You'll soon smell a belt with 25mm of side-play as it incinerates itself.

 

[Topcat47]

Any alternatives to the Yanmar sourced Hitachi alternator? Mine seems to be devoid of any part no to serial number and I will be needing a replacement when it dies.

 

[JumbleDuck]

Any alternatives to the Yanmar sourced Hitachi alternator? Mine seems to be devoid of any part no to serial number and I will be needing a replacement when it dies.

I bought one from A Bloke On Ebay - well, A Company On Ebay. It appears to be a recon Hitachi one, branded "Cargo", who do a lot of commercial vehicle electrics. Works fine, cost forty quid, ish.

 

[Topcat47]

I bought one from A Bloke On Ebay - well, A Company On Ebay. It appears to be a recon Hitachi one, branded "Cargo", who do a lot of commercial vehicle electrics. Works fine, cost forty quid, ish.

OK but how will I know it's the right one? What are the relevant specs?