runs only in one throttle position

[FAC]

my 25 hp johnson only runs in one throttle position it will start and run at somewere between the start postion and shift position if i try to go back to idle the engine slows down and stalls if i try and accelerate the motor will run for about 2 seconds no matter how fast i push the throttle forward what could be the problem? i am not sure i have the right plugs can wrong plugs cause this? i have model number j25telcnb can someone tell me what plugs should be in it?

thanks
Forrest

 

[bktheking]

Re: runs only in one throttle position

Carb probably needs to be removed and cleaned as a starting point.

 

[steelespike]

Re: runs only in one throttle position

See if a little choke helps.Most likely a dirty carb. Rebuild with attention to
all passages and jets.

 

[FAC]

Re: runs only in one throttle position

if i choke the engine even a little it dies like i was lowering the throttle this is why i thought it was not in need of a carb cleaning

 

[bktheking]

Re: runs only in one throttle position

i have model number j25telcnb can someone tell me what plugs should be in it?

thanks
Forrest

QL77JC4

High speed circuit probably gummed up, choke will still have an effect on the idle if the idle circuit is working. High speed and idle are 2 seperate circuits in a carb.

 

[tashasdaddy]

Re: runs only in one throttle position

it is an 1982 motor, it is time to clean the carbs, install a rebuild kit, and replace all fuel lines with alcohol resistant fuel lines. carb to tank. you have a fixed high speed jet , behind the drain plug on the bowl, and an adjustable low speed jet on the top. QL77JC4 gapped at .030.

also check spark and compression.

rebuild directions and carb adjustments are here. http://forums.iboats.com/showthread.php?t=299680