Jabsco raw water - pulley replacement

Vairpilot

Seaman Apprentice
Joined
Jul 30, 2008
Messages
35
We have 2 Crusaders, both have Jabsco 42730-0000 raw-water pumps on them. Have had nothing but trouble with both pumps. Main problem is that both have single-belt pullies, and we can never keep enough tension on the belts to keep them from slipping and sometimes smoking. I have taken both pumps apart, and they turn very easy by hand with the impellers removed. Of course there is considerable resistance with the impellers installed, I think it is too much for the single belts to handle. The pumps sit on metal brackets, and rely on sliding the pump to tension the belt. A pic would speak volumes, I'll try and take one tomorrow. If anyone has any insight or ideas as to how to keep the belts from slipping that would be great. I have had them tight to the point where there is little deflection, and the belts still slip on the pump pulleys.

Thank you,

Don
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Jabsco raw water - pulley replacement

A single belt should have no problems turning a raw water pump. If it works ok for a while after you tighten the belt, I would bet money you have rusty pulleys on the engines or the pumps or both. That rust will eat the sides off the belt like a grinding wheel and will make them loose again in no time, they aren't just loose, they are probably getting narrower.
Check the pulleys and let us know.
 

Vairpilot

Seaman Apprentice
Joined
Jul 30, 2008
Messages
35
Re: Jabsco raw water - pulley replacement

Actually I recently sanded paint off both pulleys in an effort to stop them from slipping. Both pulleys are aligned and there is no twisting of the belts either. All I can see and feel on the v-grooves is residue from the belts and they seem quite sticky, almost like belt dressing had been applied. How tight is too tight?

Would love to convert to a serpentine belt, but on these old engines it would be tough.
 

sdowney717

Petty Officer 2nd Class
Joined
Jul 16, 2011
Messages
155
Re: Jabsco raw water - pulley replacement

The pulleys should not be sticky with melted rubber.

Belts come in various widths across the top.
If your belt is too narrow, it wont fit properly in the groove.
A new belt should sit about level with the pulley edges.

If it is not the right size on its width as in too narrow, the belt will be riding in the bottom of the pulley.
Then it wont fit and grab on the side face edges and it will slip.
Belts work by their fit on the pulley edges, they work by the friction wedging effect on the sides of the belt meeting with the inner face surface of the pulley.

My boat engines use the wider belts.

I have bought big wider belts from Napa.

I think mine are the 5L width which is 5/8 across the top. A car might use 1/2 or 3/8 width V belts.

L belts are a different shape than V belts.
L belts I think are flatter, not as deep wedge as V belts.

My pumps are Jabsco 5330 and they dont slip and they are not super tight.
The belts run sort of on the loose side and have never slipped.

http://seekbelts.com/beltsizes/5lfractionalwedgewrappedvbelts.html

Here is a pic of my pump drive belt.

You can see I painted the entire pulley and it has worked fine.
Rusted pulley will wear out belts.
5016210084_9c07f3ff5b_z.jpg


5016209970_83e18df0d9_z.jpg
 

captk

Petty Officer 1st Class
Joined
Apr 4, 2008
Messages
252
Re: Jabsco raw water - pulley replacement

When you rebuilt the pumps did you put the paper shims, "gaskets" in place? Those are shims and not gaskets and you can not put permatex in place of them.
 

captk

Petty Officer 1st Class
Joined
Apr 4, 2008
Messages
252
Re: Jabsco raw water - pulley replacement

Any Luck? we are all curious. this is a question many of us have.
 
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