94 yamaha 650 waverunner smoking no power

[dalepatter]

I just bought two used waverunners. One will only stay running if I give it full throttle. It smokes a lot and does not have much power. If I let go of full throttle it dies. I managed to get back to the dock and let it sit for a while, then I was able to go at normal speed for a loop around the lake before slowly losing power again. It only had power that one time, I let it sit again and still a ton of smoke and no power. Just a small water jet out the back. I pulled the choke on the other ski that runs great when it was all warmed up and when the choke is pulled all the way, it runs like the bad ski. It runs the best at first the just barely moves. I am new to having a waverunner so any help would be greatly appreciated. Thanks...

 

[tashasdaddy]

Re: 94 yamaha 650 waverunner smoking no power

sounds like you have a fuel delivery problem. but before spending any money, check the compression and spark on both motors. should be within 10% of each other. did you mix your fuel 50-1. those are 2 cycle motors, without automix. also the jet may need to be rebuilt. i have a 93 500 that runs when all the new ones quit. never spent a cent on it other than normal maintainance.

 

[Jeff Walkowiak]

Re: 94 yamaha 650 waverunner smoking no power

how old is the gas in the tank??? over 3 months old it should be removed and the tank cleaned, then rebuild the carb and it should run ok if the compression is good, it probably is good though it sounds like fuel issues.

 

[dalepatter]

Re: 94 yamaha 650 waverunner smoking no power

The fuel in the tank is probably old. I bought them this summer from someone else who may not have run them in a while. I added fuel to the fuel that was already in the tanks at a 50:1 ratio. The oil injectors have been bypassed on both machines. I will clean out the old fuel and see if it will idle on the trailer. the other one idles just fine. The bad one needs throttle to idle and has a lot of smoke and oil coming out. Where is the best place to buy a carb rebuild kit? Thanks....

 

[JUSTINTIME]

Re: 94 yamaha 650 waverunner smoking no power

rebuild the carbs
they might sell them here or ebay