'92 Waverunner sudden rpm drop

[BILL47]

I have cleaned all fuel lines, gas tank, carburetor, pulled out temperature sensor and checked with ohmeter, new plugs, flushed out all water/cooling lines, pulled off exhaust. Starts and runs fine, reaches good rpm, and within 1-2 mins, it shuts down to idle speed. Trying to accelerate does nothing except seems to bog it down some. Have not checked compression but recently pulled off heads and re-assembled. I adjusted carburetor needles to specs, and have opened the high speed needle several times. Any suggestions?

 

[JUSTINTIME]

Re: '92 Waverunner sudden rpm drop

rebuild the carbs

 

[tashasdaddy]

Re: '92 Waverunner sudden rpm drop

check compression when warm and acting up, could have a head warping, and when warm.. have you retorqued the head after running. if that is good i agree, rebuild the carbs. i have a 93.

 

[BILL47]

Re: '92 Waverunner sudden rpm drop

I'm going to try the carb first.

 

[BILL47]

Re: 92' waverunner overheating

Re: 92' waverunner overheating

I've done everything I can think of. Still starts off fine then shuts down to 2500 rpm. Checked temperature sensor. Changed out CDI. Done all the fuel things including rebuilt carb. It's overheating. It's not getting cooling water. Blew all hoses out. No weeds etc. Impeller turns good. The cooling intake works on a pressure differential-vacuum thing, right? no water pump per se? Exhaust must create the differential sucking in water? Is there something in the exhaust that's screwed up?
Bill

 

[JUSTINTIME]

Re: 92' waverunner overheating

Re: 92' waverunner overheating

if it overheats in the water yes pump is clogged
if it overheats on land with flushing then you got sand or crud in the cooling systems

 

[CUCULANDRA]

Re: '92 Waverunner sudden rpm drop

Your Wavreunner Is Going Into S.a.f.e. Mode Witch Limits The Engine Revs To Around 2500rpm. The Cdi Thinks It Is Overheating, It Might Be Right. Check The Inlet Hose For Pump And Blow It Out With Compressed Air. Pull The Head Off And Check The Passgaes For Sand, Also Might Want To Pull Exhaust Out And Check For Cloggs. The Pump Will Not Overheat, Only The Engine Will.

 

[Jeff Walkowiak]

Re: '92 Waverunner sudden rpm drop

could be a bad sensor giving a false reading to the box,, pretty common with yamaha

 

[BILL47]

Re: '92 Waverunner sudden rpm drop

I pulled sensor out and checked it in hot water with ohmmeter. The engine is overheating. I can't figure out why water is not be sucked in. All hoses are clean. Is there something about the exhaust system that might be messed up? and thereby not bringing cooling water in?

 

[Jeff Walkowiak]

Re: '92 Waverunner sudden rpm drop

if the muffler is clogged or if the water line to it is clogged it can run hot, or if the rubber hose is bad and causing a restriction inside