yammi 2ooo 90 hp. runs@2k rpms. then clears up!

[hunting lee]

well maybe someone has encountered this problem.
this yami 2000 90 hp. has now for the second outing for unkhonw reasons after running perfect decided to run only @ 2000 rpms. it is not hot,there is plenty of water coming out thru the pee hole. the head is warm or hot. but can be touched. no buzzers or lights.then after a few minutes the engine returns to normal functions as if nothing ever happened. i changed the impellor pump 20 hrs. ago. i checked the overheating sensor and the buzzer goes off. can anyone offer assistance? thanks HL

[jb123]

check your oil levels when this happens..if you say your horn and thermosensors work correctly, then it must be your oil levels.mayebe a clogged oil filter or pinched line restricting flow.

[hunting lee]

my yami motor oil is pre mixed with gas 50:1

[jb123]

have you checked/replaced the thermostats and prv ? cheap insurance to replace if unsure rather than to overheat your motor.yammies are extremely sensitive to water flow.

[hunting lee]

thanks for the reply. i will try changing the thermostat and prv .

[Ken]

lee,
You can check the thermostat and prv w/o replacing them.
For the 'stat, just remove the cover at the top of the head and pull the 'stat. Clean if necessary and then place in a pan of heated water with thermometer - should be fully open, approx 0.120 iches, at 140 degrees f.
The prv, aka pressure control valve, aka poppit valve, is also fairly easy to remove and check.
Two small bolts hold the cover on. There will be a spring under the cover that holds the valve in place. Remove and check for debris that can cause the valve to stick open. While you are at it, you might want to replace the old style valve with a new mushroom design valve that is less likely to stick open from debris.
Good luck [img]smile.gif[/img] ,
Ken K

[hunting lee]

Ken, Thanks for the heads up. I will try what you suggested and keep you posted. HL

[hunting lee]

oh yeah ken. were is the prv or poppit located ?
i see the stat. and the heat sensor. is that prv valve under the stat?

[jb123]

should be centered under your bottom cylinders, look for the approx 1" water hose...it is under there.

[hunting lee]

thanks alot for your reply jb 123.

[Ken]

lee,
Take a look at this link from the online catalog above - item #40:

http://www.boats.net/yamaha/partsyst...mponent=370590

Looks like the PCV is under the 'stat cover and just below the 'stat - I didn't know that [img]smile.gif[/img] !!!
It's different on your 90 compared to my 115.
Just goes to show you, you are never too OLD to learn (I have a FEW years under my belt [img]smile.gif[/img] ).
Ken K

[hunting lee]

thanks for the refrences on the prv . i thought it was under the stat, but was not sure. i took it apart checked the stat and opens as you directed @140deg. i will replace the prv with mushroom type. oh yeah had some debris . cleaned it . lets see on the next outing! thanks a bunch
KEN>>>>