nightflight
Seaman Apprentice
- Joined
- Sep 1, 2008
- Messages
- 40
I purchased a replacement '93 johnson 90 hp v4 for my wellcraft. Tested compression all between 110 and 125. Connected the wiring everything seems to match up with the old kaput( ran with water in the oil tank) '84 model . Fired it up and it wants to run at about 2500-3000 rpm.or very fast 1/2 throttle speed( no tach)
It seems to be sucking fuel from some where it's not supposed to. I'm thinking stuck float, maybe stuck primer, something sending fuel straight to the engine and not the way it's supposed to.
The schrader valve on the manual primer "RED" switch was leaking so I fiddled with it and it idled down it ran about 30 minutes at regular idle rpm with normal response to the throlle.
I swapped primer coils with the '84 and fired it up, now back to fast rpm's.
How can I isolate where the fuel dump is comoing from to avoid unnecessary tear down?
Engine rested on its side in my garage for about a year before I hung it on the boat. Maybe that messed up the float arrangement. It got some rough handling while moving since I only have one good shoulder to muscle it with and can no longer move a 90 by myself.
First thought is to disengage primer lines to the carb base and see if that stops the fast idle. Next I think,, take off fuel line and once the bowls lower the engine should slow down til it runs out of fuel, next put fuel line on and pinch off a carb feed line one at the time to see which carb is sending the fuel.
Assuming it is stuck float??
Then what is the best way to unstick floats? ( if that is the problem)
Should I be able to see fuel coming into the throat without the engine running if the float is stuck or if fuel is bypassing the float valve?
Never had or heard of this one before.
What else could cause the high speed at crank up???
Butterflys and linkages appear normal
Strange discovery not related to carbs same engine, water tee on the pisser line was shooting water on the lower engine block and looks like it was for years( rusty head bolts). Can't find any hose that the tee should have fed. This was probably why the owner couldn't make the engine run right with salt water shooting on coils.
It seems to be sucking fuel from some where it's not supposed to. I'm thinking stuck float, maybe stuck primer, something sending fuel straight to the engine and not the way it's supposed to.
The schrader valve on the manual primer "RED" switch was leaking so I fiddled with it and it idled down it ran about 30 minutes at regular idle rpm with normal response to the throlle.
I swapped primer coils with the '84 and fired it up, now back to fast rpm's.
How can I isolate where the fuel dump is comoing from to avoid unnecessary tear down?
Engine rested on its side in my garage for about a year before I hung it on the boat. Maybe that messed up the float arrangement. It got some rough handling while moving since I only have one good shoulder to muscle it with and can no longer move a 90 by myself.
First thought is to disengage primer lines to the carb base and see if that stops the fast idle. Next I think,, take off fuel line and once the bowls lower the engine should slow down til it runs out of fuel, next put fuel line on and pinch off a carb feed line one at the time to see which carb is sending the fuel.
Assuming it is stuck float??
Then what is the best way to unstick floats? ( if that is the problem)
Should I be able to see fuel coming into the throat without the engine running if the float is stuck or if fuel is bypassing the float valve?
Never had or heard of this one before.
What else could cause the high speed at crank up???
Butterflys and linkages appear normal
Strange discovery not related to carbs same engine, water tee on the pisser line was shooting water on the lower engine block and looks like it was for years( rusty head bolts). Can't find any hose that the tee should have fed. This was probably why the owner couldn't make the engine run right with salt water shooting on coils.
