Feb 25, 2002

Dear Paul, Doug: I have not have bearing problems with the raw water pump. I installed a 100A Ample Power Alternator to replace the half-size original equipment, and have had some brief slippage when starting the engine with refrigeration on. I also had to retighten once at sea, and a strong locking grip plyer helps there.

On my Westerbeke 30, I discovered that the lower pulley is made of two half rings, with an undersized groove so that the belt cannot go all the way down and in. The top, larger pulley is wider, and compatible with the alternators, new and old. I have never seen pulleys of different groove size for the same belt on any engine!

Has any one noticed the same problem with the lower, on-shaft pulley?

Also, has any one tried to crank the engine manually? I donít have a crank, but the female fitting is present ahead of that pulley. Wonder if it be worthwhile making/getting a crank? or if it is physically impossible to crank manually anyway, especially for an active but fragile backed 67 geezer...? Bert dF SWII 80K

1548 Feb 13, 2002

I have been using high output alternators for about 13 years, with a single belt. The belt has a tendency to slip when charging at high amperes, but usually the regulator only allows it to do such charging for a few minutes. The belt needs to be VERY tight. My mechanic says the belt should have about Ĺ" deflection when pressed down half-way between the alternator and the circulating pump. This is tested with rather firm pressure. I have rarely been able to get it tighter than that even though using a pry-bar between the alternator and the engine block. I have worn out a belt twice in that time. The size of the pulley on the alternator makes a difference. The smaller the pulley, the greater force needed from the belt and the greater chance of slippage. I always carry a spare belt. Belt dressing helps a little to prevent slipping. The maximum charging rate has been about 90 amps.

Dick Weaver, SWII75K

1549 Feb 13, 2002

I am relieved to hear that much tension CAN be placed upon the alternator bearings but I have so far rebuilt the coolant circulation pump twice and replaced it, new, once and each time the bearings hade been severely compromised..... Have I been doing something else wrong?

Paul, Sea Quill # 29K