18 hp Nissan hesitation

[penoe01]

Hi,
I have a 1999 Nissan 18E2. I recently disassembled the carb and dipped it for four hours then reassembled it with new gaskets and o-rings(did not replace float or needle valve). Also, replaced all fuel lines, primer bulb, and installed a fuel/water seperator. The fuel pump body and outside gasket are new however the diaphram is about a year old and the gasket between the carb body and diaphram has not been replaced since I've owned it. My problem is when I accelerate under load the engine hesitates and kinda bogs down. Once it reaches a certain point it takes off and runs fine. Any ideas would be greatly appreciated.

 

[Sea Rider]

Re: 18 hp Nissan hesitation

Welcome to the forums,

Have you changed carb neck 13 year old o'ring ? By a certain point you mean, idle to medium rpm ? how about 3/4 throttle to wot on a long run ? I'll bet you have not re torqued or changed head gasket since engine was new, if so, seems a dried out/ excesive hardened head gasket typical failure.

Happy Boating

 

[penoe01]

Re: 18 hp Nissan hesitation

What do you mean by carb neck? Yes, it has o-rings between carb and engine and between two carb halfs. 3/4 to wot on a long run does fine. Idle is fine. If you accelerate really really slowly it does ok all the way through. I am the second owner.

Welcome to the forums,

Have you changed carb neck 13 year old o'ring ? By a certain point you mean, idle to medium rpm ? how about 3/4 throttle to wot on a long run ? I'll bet you have not re torqued or changed head gasket since engine was new, if so, seems a dried out/ excesive hardened head gasket typical failure.

Happy Boating

 

[Sea Rider]

Re: 18 hp Nissan hesitation

If engine runs fine at all throttle ranges, and only bothers with load, seems prop is slipping on hub, perform slip prop test...

Happy Boating