Need Rodbolt's advice on T9.9 cooling problem

Jadelinski

Recruit
Joined
May 12, 2008
Messages
3
Hello,
I have a 1993 T9.9 EXHR in which I replaced the original water pump impeller with a "Sierra" OEM equivalent. Prior to the replacement, water would always come out the pee hole on startup. Now only drips comes out until, running it for a minute or so, shutting off, letting set for a minute and restarting, it then begins to pee and operates fine. I assume the thermostat is opening allowing flow. I've motored for 15 minutes like this at 1/3 throttle with no problems. My question, is there a PRV on the cooling system on this engine and if so, where is it (Seloc manual is vague)? I have double checked the impeller installation and know it is correct, as witnessed by the fact it pumps fine once the engine is warm. I have no reason to suspect an unusual blockage, as this motor is used summers only in a clean fresh water lake and have never had prior problems. The old impeller was not that bad of shape (intact). Any thoughts or suggestions would be greatly appreciated.

Thanks
 

BruceAML

Petty Officer 1st Class
Joined
Feb 26, 2007
Messages
371
Re: Need Rodbolt's advice on T9.9 cooling problem

First of all you should order a genuine Yamaha factory manual. There is no substitute for it. Second, you should order a genuine Yamaha water pump repair kit 682-W0078-A1-00.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Need Rodbolt's advice on T9.9 cooling problem

I dont like aftermarket stuff much.
carefully clean all the passages you can access, paying careful attention to the two nipples on the port side of the powerhead, try to run a small wire through all of it. make sure the t-stat is closing correctly or it dumps water pressure.
no PRV on that motor.
 

Jadelinski

Recruit
Joined
May 12, 2008
Messages
3
Re: Need Rodbolt's advice on T9.9 cooling problem

I appreciate the advice. I have ordered a new T-Stat as I believe that may be part of the problem.

Thanks again.
 
Top