Changing the Belt on the M25XPB

DaveJ

DaveJ

.
Apr 2, 2013
451
Catalina 310 Niagara-on-the-Lake
Tried to change the belt on my engine and was unsuccessful. Shouldn't be hard....what am I doing wrong? I loosened the 1/2" bolt on the slotted bracket at the top of the alternator, I found the 9/16" bolt under the alternator, loosened it, but when I tried to move the alternator it only went about 1/4" and would not move. Not enough slack to change the belt. I felt around back and there seemed to be another bolt, but I don't think there was a tool made that will ever access it....not sure if this bolt needs to be loosened? Sorry no pictures.....
Anyone have a solution for me?

Cheers
 
S

sailnewbie

.
Feb 13, 2016
551
macgreggor venture 224 ohio river
Loosen top bolt that should slide in bracket,loosen bottom alternator bolt and it should slide several inches, may need loosen bracket bolt or bolts to allow some movement
 
DaveJ

DaveJ

.
Apr 2, 2013
451
Catalina 310 Niagara-on-the-Lake
Not sure if there are 2 bolts at the bottom (eyes aren't what they used to be) but it seemed that when I loosened the top and the bottom that the alternator was hitting the bracket and couldn't move any further. The top bolt is close to the end for tightening and should have a couple of inches of travel for adjustment, but seems to be hitting the bracket. Sounds like there is another bolt to loosen the bracket? I felt one at the back, very limited access, hope there is another solution. Thanks.

Cheers
 
S

sailnewbie

.
Feb 13, 2016
551
macgreggor venture 224 ohio river
I'm basing my thoughts off a picture I pulled from the internet of that engine, but there should be the top bolt that will slide in the bracket and a main bolt on the bottom of alternator. You may try pulling top bolt out and seeing if it'll go the extra distance
 
DaveJ

DaveJ

.
Apr 2, 2013
451
Catalina 310 Niagara-on-the-Lake
Ah, I see (I think), there may be no adjustment because of a clearance issue, perhaps the new belt should be a little bit longer, I have adjustment in that direction. Then I would be able to loosen it off for an easy change.
Thanks guys

Cheers
 
njlarry

njlarry

.
Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
I have the same problem wit to mine. You must take the alternator off to change the belt. PITA.
 
njlarry

njlarry

.
Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
Mine too, although I have changed to the oberdorfer water pump.
 
KZW

KZW

.
May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
This is my engine with the Oberdorfer pump. However, there was plenty of clearance with the Sherwood and no issue with the alternator. It swings on one bolt on the bottom if you loosen the bolt in the bracket. My issue wasn't getting the old belt off, it was getting the thing tight enough after the new one was put on. I made a pulley spreader. In the old days these were easy to get, now, with serpentine belts, they are an anachronism.
 

Attachments

KZW

KZW

.
May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
Stu,

The picture shown in your reference, October 14, 2008, 11:52:01 AM, is not the engine in the Catalina 310. That tool won't fit in our engine. The raw water pump gets in the way. A smaller one, that fits between the two upper pulleys (alternator and coolant pump) is needed. I couldn't find a commercial one so I made my own. I used a small turnbuckle and a couple of eye bolts (cut up) and a bit of welding to put it all together.
 
Stu Jackson

Stu Jackson

.
Feb 26, 2004
22,776
Catalina 34 224 Maple Bay, BC, Canada
KZW said:
That tool won't fit in our engine.
Click to expand
Perhaps, perhaps not. The concept was to show people who don't know what it is at all at least what it looks like. Good on you for making one up. :)
 
DaveJ

DaveJ

.
Apr 2, 2013
451
Catalina 310 Niagara-on-the-Lake
Hopefully I'm not beating this to death, but if available, wouldn't a belt an inch or so longer be helpful in this situation? I have lots of travel on the slotted bracket.
Cheers
 
njlarry

njlarry

.
Sep 23, 2009
1,475
O'Day 34-At Last Rock Hall, Md
I have tried longer belts but ran out of room to tension them. They were napa belts that always stretched after a few hours. The universal factory belt I have now does not. Don't know if it comes in a larger size. I think that the bracket needs to be redesigned.
 
JK_Boston_Catalina310

JK_Boston_Catalina310

.
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
DaveJ said:
Ah, I see (I think), there may be no adjustment because of a clearance issue, perhaps the new belt should be a little bit longer, I have adjustment in that direction. Then I would be able to loosen it off for an easy change.
Thanks guys

Cheers
Click to expand
My guess is that your previous owner used a belt that was two short. Also, I do have to push in a little on the alternator when I change the belt because the hose from the raw water runs behind the alternator.

Hope you can figure it out.

Good luck,

Jesse
 
C

Clydo

.
May 28, 2013
341
Catalina C310 SF Bay/Delta
DaveJ said:
Tried to change the belt on my engine and was unsuccessful. Shouldn't be hard....what am I doing wrong? I loosened the 1/2" bolt on the slotted bracket at the top of the alternator, I found the 9/16" bolt under the alternator, loosened it, but when I tried to move the alternator it only went about 1/4" and would not move. Not enough slack to change the belt. I felt around back and there seemed to be another bolt, but I don't think there was a tool made that will ever access it....not sure if this bolt needs to be loosened? Sorry no pictures.....
Anyone have a solution for me?

Cheers
Click to expand
There are some belts that have the cuts in the top rather then bottom. Suppose to give better grip. Can't think
of the name now. Tried one on my C30 and seemed to work ok but don't know if gave better grip.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA
 
weekendrken

weekendrken

.
May 7, 2011
281
C - 30 # 3573 Lake NormanNC formerly Bflo NY
Old post, but it is a Dayco "Top Cog" belt -- much better in terms of slippage and also heat dissipation. My Westerbeke distributor recommended using the Dayco (tellingly, NOT recommending the OEM Wb belt.)
-Ken


Clydo said:
There are some belts that have the cuts in the top rather then bottom. Suppose to give better grip. Can't think
of the name now. Tried one on my C30 and seemed to work ok but don't know if gave better grip.

Clyde Thorington
C310 # 245
ILEAN TOO
San Jose, CA
Click to expand
 
KZW

KZW

.
May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
Do you have a part number?

weekendrken said:
Old post, but it is a Dayco "Top Cog" belt -- much better in terms of slippage and also heat dissipation. My Westerbeke distributor recommended using the Dayco (tellingly, NOT recommending the OEM Wb belt.)
-Ken
Click to expand
 
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