wont throttle up very high

[rsw21282]

I have an late 80s 85hp force, i took it out today and it runs fine, idle and a bit of throttle, however when i try to throttle it up more than maybe 1/4 throttle it wants to die, i took it out and while i was doing the freshwater rinse i gave it a bit of gas and it throttles up fine out of water and about 2wks ago would throttle up momentarily and die which is why i changed the fuel pump diaphragm which was bad, but now it wont even throttle up for a min. it dies right when i give it to much gas, i also cleaned carbs they look fine, changed fuel filters and spark plugs. anyone have any suggestions?

 

[1fullforce]

Re: wont throttle up very high

clean the spark plugs and maybe replace them if they been there for a while, also check for spark on each of 3 cylinders, did you buy the rebuilt kits for each carbs? or just cleaned them? you are priming the fuel line bulb until it gets hard before starting engine? adjust the idle mixture screws , (turn each clockwise until lightly seated turn counterclockwise 1 1/2 turns and start adjusting from there.

 

[rsw21282]

Re: wont throttle up very high

idle speed is seems good, spark plugs are all 3 new as in today was first time running them, and just cleaned carbs not rebuilt, all carbs seemed clean and fine. It doesnt run rough at all just wont go past 1/4 throttle without dieing, saw a post about a fuel tank vent clogged but out of water will throttle all the way up so what would the drag in water cause the motor to die at throttle up?

 

[steelespike]

Re: wont throttle up very high

Generally a motor that is running a little lean will respond normally on a hose,
there is no back pressure.The drag of the prop would make it even worse.It would appear the high speed circuit could be gunked up.You might try squeezing the primer bulb if it helps it may indicate a fuel supply restriction.
Can be very bad for the motor to operate in a lean condition for an extended period.

 

[mthieme]

Re: wont throttle up very high

Possible saturated float. Did you check this when you had the carb apart?

 

[pnwboat]

Re: wont throttle up very high

Certainly sounds like a air/fuel delivery problem. Might want to check for a broken reed valve. They sit underneath the carbs. Simple to check once you take the carbs and manifold adapter off.