300/440/550 rpms keep climbing

[crashnburn86]

just got my friends 550/650 conversion together and we went to start it. When it starts the rpms just keep climbing so i shut it off. What could be causing this?

 

[x2ryder]

air leak

 

[KawiJS550]

does it shut off when you hit the kill switch?

 

[jetski9010]

Check all the easy stuff for an air leak first. Is the carb bolts on right? is the intake manfild on right? If none of the easy stuff looks bad start looking into things like crankseals? What this motor already used and you just put it in or did you just have the motor apart?

 

[nokfir]

check to see that the throttle cable isnt pulled to far on the lever and carb. mine was too tight causes it to rev up

 

[steve1981]

^^ what he said. i just fired up my 701 square after the build and that was my problem also.

 

[Liquid-6]

It will also just climb when its outa water. My bro's 550 climbs like then when we run it out of the water. Once its in the lake its fine. Just kinda lean on idle.

If it climbs in the water, do what the other guys have said.

 

[5810]

air leak or throttle X2

 

[KawiJS550]

Again, when you hit the kill switch, does it actually shut down the engine? If the engine shuts off by hitting the kill switch, it is not necessarily an air leak... The engine just isn't leaded up, and it can idle freely... thus raising RPMs. Is it going WIDE OPEN?