Blocked powerhead water jacket

[pontoon chief]

Took in a F9.9 Yamaha four stroke with an overheating problem.This is a year 2000,and was sent out recently with a new waterpump inpeller.<br />While running the motor for an inspection I noticed steam coming out of the pisser,but no water.I pulled the hose nipples tubes off of the head and there was no water at the head,and I saw the nipple was plugged with a white powder like substance.Pulled the nipple out of the head and found the head is also plugged with the same stuff.It is hard,and packed tight.Any idea of how I can clean out the water jacket in this motor.<br /><br />A check of the waterpump foung a fried waterpump housing and a rather small water pump inpeller,as the only thing left was the center,no blades.<br />Any Ideas?

 

[Ray Neudecker]

Re: Blocked powerhead water jacket

First repace impellor and see what happens.