Alternator Bracket for Universal M25XPB Final Setup

Afraal

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May 29, 2023
39
Catalina 310 Flowery Branch
Hi everyone,

I wanted to share a couple of pictures of the finished result of replacing the OEM alternator bracket in my engine. The OEM bracket didn't allow me to put more tension on the belt and that was causing all kind of problems. I found some great tips here in this forum which guided me to my final solution.

1. The metal plate is a 2''x4'', 1/4" thick steel plate I purchased from McMaster.com. You can also find 1/4"thick bars at your local store and cut it to a 4'' length.

2. The tension arm is a Balmar UBB ( https://defender.com/en_us/balmar-universal-adjustment-arm-combo-with-belt-buddy-tensioner-ubb ). You can also use the UAA version. The difference is that the UBB comes with a "Belt Buddy Tensioner" contraption. I liked having that, but the UAA version works perfectly fine.

3. The holes for the engine bolts I drilled with a 1/4" drill bit. The hole for the arm I drilled with a 3/8" drill bit.

4. The Balmar arm is a bit long, so I had to cut a couple of inches off for it to fit.

5. Bolts, washers, and a few extra washers on the alternator side to fill the 1/4" gap between the alternator housing and the new arm.

It worked great. It gives more room for the alternator to swing, and the Belt Buddy makes it easy to tension the belt. Also, the arm should now be long enough to accomodate a future upgrade to a bigger alternator.

In retrospective, I should have drilled the arm hole 5-10 mm to the left. That would have allowed for a bit more room between the arm and the engine bolts, and also a bit more room between the alternator side of the arm and the engine cover. But, this time I was very lucky and everything fit.

I took the boat for a test ride yesterday and it ran smooth.

Happy Sailing!
 

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Likes: JRT and dmax
Jan 7, 2011
5,159
Oday 322 East Chicago, IN
It looks beefy and easy to adjust.
engine is also very clean and tidy.

nice work.

Greg
 
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Likes: Afraal
Apr 10, 2010
84
Catalina 310 166 Dartmouth, Nova Scotia
What is the size and specs of the belt, is it still the original one? Has anyone ever used a Kevlar belt for this application, and how did that work out? Thanks.
 
Sep 24, 2018
2,956
O'Day 25 Chicago
That's one of the prettiest boat engines I've ever seen! I thought the Westerbeke M25's had the newer bracket?
 

Afraal

.
May 29, 2023
39
Catalina 310 Flowery Branch
What is the size and specs of the belt, is it still the original one? Has anyone ever used a Kevlar belt for this application, and how did that work out? Thanks.
Hey sorry for the extremely late reply. I used the OEM "Universal" brand belt that I got from Catalina Direct. I tried a few belt options from Napa Auto parts but the Universal seemed to fit better. The good thing about the new bracket is that I have a bit more tensioning range for the belt.