1986 force 50 backfire

[basshoss]

Ok, I have an 86 force 50 hp on a 14 ' lonestar. Th eboat runs great after a carb rebuild and a fuelpump rebuild. occasionally it backfires when I go from neutral to wot. any ideas?
It runs really nice and starts right away, it does seem like it the rpms could go higher (doesnt have a tach, one is on order). When going, it sounds great until the last 5% of throttle in which it bogs till I back off?

 

[steelespike]

Re: 1986 force 50 backfire

Sounds like you may be running a little lean.Sneeze could be the idle mixture.
Adjust the screw with the motor warm in gear.May need to be slightly richer. Bogging at full throttle could be timing or running lean.running lean can burn a piston.Carb could need more cleaning or adjusting of the float.
Standard main jet is .084.

 

[basshoss]

Re: 1986 force 50 backfire

Its not a sneeze it is a backfire. I am running 1 1/8 turns from lightly seated. I think the float may need a little more adjusting also.

 

[bowhuntrrl]

Re: 1986 force 50 backfire

Sounds like maybe a weak or broken reed valve.

 

[basshoss]

Re: 1986 force 50 backfire

can you explain why that would be the cause. I am curious. Are they tough to change, I visually looked at them when I rebuilt the carb and they looked ok but I guess if they are weak you can not tell till they are off.

 

[bowhuntrrl]

Re: 1986 force 50 backfire

can you explain why that would be the cause. I am curious. Are they tough to change, I visually looked at them when I rebuilt the carb and they looked ok but I guess if they are weak you can not tell till they are off.

Is it backfiring out the intake or the exhaust ?? Reeds usually cause an exhaust backfire. Intake "sneeze" or backfire is usually caused by running lean or other carb problems.