Why replace my Impeller?

I have a 1971 Johnson 9.5 that has net been used for 5 years. It ran fine last time it was out and is used in fresh water. I have been advised to replace the impeller as well as do a general tune up. Why is it important to replace the impeller?

Re: Why replace my Impeller?

The water pump impeller is th heart of the cooling system for your motor. It's a regular maintenance item and should be replaced on a regular basis. Without the pump working, the motor will overheat resulting in cylinder damage. Motors that have been stored for long periods of time need the pump replaced. The impeller 'arms' take a set and don't pump water well. Address the water pump first, everything else as needed.

BTW, while you asked a good question, you also asked the same question in your other post. Try to keep your questions in one post, it lets folks follow your progress and prevents folks from jumping around trying to address your specific motor issues.

Re: Why replace my Impeller?

And if you want an even better reason as to why you should change your impeller/water pump regularly, search out the price of new power heads. The price of an impeller is very cheap compared to the catastrophic consequences its failure creates.

Re: Why replace my Impeller?

Bingo what Xcusme said.

Re: Why replace my Impeller?

Correct. What he didn't mention is that they are rubber and spin in a metal housing at high speed and thus they wear out plain and simple. In addition they dry up and get brittle and break up sending little pieces everywhere which is a bad thing.

I have a fried 1990 15hp sitting in my garage as my neighbour did not notice the pee'ing had stopped until it didn't run any more...Now the paint is peeled off the head and thermostat housing and the compression is close to 50 psi in each.