Mercruiser Impeller

[cimy3]

Hello. I have a 1989 5.0L merc with an Alpha One Drive. I use this boat for fishing and while at a troll, the engine overheats, but at any higher RPM it runs in the normal range.

I am assuming that it is the impeller due to the fact that it has not been changed in 3 years. I have read numerous posts and seen many service manuals....not sure which one is for my outdrive...can someone point me to the correct manual.

Also, which is a better impeller kit...mercruiser or quicksilver.

Thanks, Ray

 

[Ryan00TJ]

Re: Mercruiser Impeller

The impeller is likely the problem. I had a friend that let his go for about the same time and it was in pretty rough shape. When we added a new impeller it pumped alot more water out the tips at idle.

Quicksilver and Merc are the same. I've used Sierra, GLM and Quicksilver water pump kits and have not a problem with any of the above. Since the drive has not seen any maintenance in 3 years I would pull it and grease the u joints and a basic lookover of the drive. Also buy the water pump kit with the upper and lower bases instead of just an impellar.

Merc manual for Alpha 1's is #6. They can be picked up off Ebay in good condition for about $20 and are well worth it.

http://www.mercstuff.com/waterpumpinst.htm

 

[cimy3]

Re: Mercruiser Impeller

Thanks for the reply. I will pull and grease as stated.