Beta Bd722 fitting replacement Polyvee alternator kit -advice needed

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Cornish Bluenose

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I have just fitted a polyvee replacement alternator kit to my Beta 722 20hp engine to replace the standard v pulley system. The main issue in removing the existing pulleys was removing the pulley from the alternator and gripping the pulley while loosening the retaining nut.
The advice I need is after fitting the new kit and replacing the v belt system with the polyvee belt, this new belt rubs against the water pump casing.
Have any forum users fitted this kit and suffered the same problem..?
Any solutions or advice welcome...
 
No-one else has responded, so I will: assuming you bought the kit from Beta, surely the problem is theirs? They're well-known for their helpfulness, so why not give them a call?
Incidentally I had the 722's 28hp big brother on my last boat, with a polyvee from new. You won't regret installing it. And incidentally it never came close to fouling on anything else.
 
Yes, definitely speak to Beta. I have the B25, similar layout to the B20. with factory fitted poly-vee belt. The belt is close to the sea-water pump, but no real likelihood of rubbing.
The belt run is behind the main body of the pump, close to the mounting.
Only if the crankshaft pulley was too far forward or oversized would rubbing seem possible.
 
Two possibilities - a spacer behind the pulley has been omitted, or the pulley has an offset centre, try fitting with the inside face turned out. Long range diagnosis, no guarantee just guessing!
 
Cornish Bluenose said:
I have just fitted a polyvee replacement alternator kit to my Beta 722 20hp engine to replace the standard v pulley system. The main issue in removing the existing pulleys was removing the pulley from the alternator and gripping the pulley while loosening the retaining nut.
The advice I need is after fitting the new kit and replacing the v belt system with the polyvee belt, this new belt rubs against the water pump casing.
Have any forum users fitted this kit and suffered the same problem..?
Any solutions or advice welcome...
Click to expand...

I have the Beta 722 with the polyvee belt and 70 A alternator fitted from new.
As already said the belt runs close to the pump body, but if it rubs something is not correctly installed.
This is how it looks on mine:
http://www.ybw.com/forums/images/attach/jpg.gif
 
Thanks for your information and help with this problem. I fitted the new pulley system after eventually removing the pulley on the alternator this weekend. The new system seems to be aligned correctly with the new arm and spacer for the alternator. The big problem is the pulley belt is rubbing on the water pump housing. I contacted Beta last week and was sent the photo with the information below. If, as they suggest the answer is to grind off the new belt, I can imagine about 1/3 of the total width would be lost..! Is this really a good idea..? Does the reduced width of the belt effect the efficiency of the new system..? Has anyone else experienced this problem..?

poly-vee%20upgrade%20INSTRUCTIONS.jpg
 
Yes, it means modify the pump mounting, which has ribs as part of the casting.
My pump is held onto the block by means of 2 small finger clamps, tightened by 8(?)mm nuts. The pump drive is a dog-clutch, so it's easy to remove the pump to modify it away from the engine.
 
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Many thanks for the technical advice. I have received an e-mail from Beta Marine with the answer to the problem...
Fix the pulleys in place and mark on the pump casing where the bowt is rubbing, remove the pump and grind off the rib that is causing the problem. I asked why this was necessary and it seems there are minor variations in the engines of this period, 2005. I would have thought that the pulleys could have been machined with a smaller diameter overall and maintained the same ratio and reduced the need to do this modification. I hope the effort of fitting this updated system is worthwhile. Once completed I will post a few photos on this thread to help others who may have the same issues fitting the polyvee upgrade to a Beta BD722.
 
How did your mod end up? I enquired with a Beta dealer this week about the polyvee conversion while keeping the 40AMP alternator ("about £120 + VAT), a was not advised of any fitting problems in advance. Bu, again, that's keeping my 40AMP alternator, which wouldn't be any different to your problem.
 
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