We are becoming acquainted with our new to us Ultra 30 for about a year now (1/2 a year in Canadian summer length). We had a bit of an issue in that the alternator stopped charging. Issue was tracked down to a bad connection at the regulator. Part of the troubleshooting process included checking and replacing the alternator belt. The alternator was at its max tension arm position so it could not be tightened further. I thought it was just stretched so went ahead and installed a new belt. The new belt cant be tensioned to the recommended 1/2" belt deflection as it to is restricted by the max arm position. All seems well, water pump pumps plenty of water and the alternator is charging. I even tried the next shortest belt, but could not get it over the pulleys as the alternator motion is restricted in the other direction by the engine. I was able to get on a friends Nonsuch and its alternator is also at the max arm position, belt a little slack but all working fine. Any comments would be appreciated.
PS Very impressed with the wealth of information and goodwill in this group. I hope to be able to contribute as I can.
Hi Bill, when I installed a new high output alternator I took the opportunity to also install a turnbuckle tensioner. Makes getting the right tension a snap. Choose the spacing and bolt sizes you need to be sure you order the correct model.
Yes, should have included the engine model. It’s a Westerbeke W27. The replacement belt I used (NAPA 7395) has a length of 40.07 in according to the specs. The next smaller one is 39.57 in. Only 1/2 an inch shorter but too short to get it over the pulleys. It’s very close but I don’t want to unnecessarily force it.
Perhaps another belt manufacturer may have something. I’ll check around.
I like Ron’s idea and will take a closer look at the geometry the next time I’m at the boat.
Another possibility is that an Imperial belt has been substituted for a metric belt at some time. Check the metric alternative.
Mike Jennings.
NS005 Chancy.
Port Moody BC.
