power loss

[walleye hunt]

Hello
I have a 9.9 Johnson motor and the problem I am having is when I go past half throttle the motor will bog but still run. And if I give it full choke It gets more power. Does anybody know what could be causing this.

Tks walleye hunt

 

[SolingSailor]

Re: power loss

Air leak in fuel line, defective fuel pump, clogged carburetor or fuel filter. Too much air, or too little fuel.

 

[kfa4303]

Re: power loss

yup. poor fuel air mix would be my guess. Go through the fuel system systematically to see if you can track down the problem. Start with the fuel tank. Make sure it's vented when underway. Inspect the lines for small holes or tares. You can test to see if the fuel pump is working by briefly disconnecting the fuel line which comes out of the pump while the motor is running. You should see fuel being pumped out. Shut motor off and reconnect the line. Now on to the carb. If you haven't cleaned it in a while, chances are that's your problem. Thoroughly clean and rebuild the carb and reinstall it. You can get a carb rebuild kit right here at iboats for about $25. Adjust the hi/lo needles according to this link and let us know what you find.

http://forums.iboats.com/showthread.php?t=167352

 

[walleye hunt]

Re: power loss

Thank you guys I will try all of the above mentioned, and will post mt progress with really old but steady motor.

 

[walleye hunt]

Re: power loss

well the motor ran great all summer, new water pump, lower seals and new fuel lines. Last time out the motor would die unless I pumped the primer ball I call that motor cpr. Could that be a fuel pump problem?

 

[freddyray21]

Re: power loss

sounds like a bad fuel pump if it will run when the primer bulb is squeezed.

 

[kfa4303]

Re: power loss

"......Last time out the motor would die unless I pumped the primer ball ...." Classics signs of a bad fuel pump. I'm not sure if they sell rebuild kits for your model. Check here at iboats. If you can't get a rebuild kit, but don't want to drop $50-$60 on a factory replacement pump, you can use pumps for other small engines made by other companies like Briggs and Stratton for about $20. You'll have to do a little modification, but it's not bad.

 

[raczekp1]

Re: power loss

i rebild fuel pump fited to 6 hp, 9,9 and 4 hp.
got fuel pump kit from Sierra(18-7823), and the same kit you can apply to this motors.
buy fuel pump kit for squere omc pump and it will fit.i'm sure

 

[msgcoons]

Re: power loss

try spraing some fuel around the base of the carb while it is running,if the rpm's increases,replacethe mounting gasket,good.