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'93 25HP J25RETS won't idle below 900RPM

25Johnny

25Johnny

Contributing Member
Gents,
This was an estate sale, latest registration 2014. Ran very rough when purchased. Good compression. Changed water pump, fuel pump, thermostat, new plugs, and wires, and rebuilt carb. Idle screw out 1-1/2 turns. Primer test fine, no leakage, good spark, link and sync, throttle plate horizontal at WOT. Difficult to start, must be very careful with the primer, motor floods easy, won't stay running. Any ideas guys?
 
25Johnny said:
Gents,
This was an estate sale, latest registration 2014. Ran very rough when purchased. Good compression. Changed water pump, fuel pump, thermostat, new plugs, and wires, and rebuilt carb. Idle screw out 1-1/2 turns. Primer test fine, no leakage, good spark, link and sync, throttle plate horizontal at WOT. Difficult to start, must be very careful with the primer, motor floods easy, won't stay running. Any ideas guys?
Click to expand...
Sounds like possible sucking air. Low speed circuit still has an obstruction. Check key way?
 
Ok made a video. Check the sneezing. Idle screw seems the best at 1-3/4 turn. Can get it to stop the lean sneeze. Seems to get worse when warm.
 
Facts for you.------I do believe it is running too lean.-----Is the throttle plate fully closed at idle ?----It must be !----Post a video showing the stop on that thin rod that goes to the back of the motor ( port side ) show how that behaves when speeding up the motor.
 
Not sure about the throttle plate, I set the sync & link at WOT to get the plate horizontal, procedure in the FSM didn't mention anything about it being fully closed at idle. But with the throttle fully closed, the engine won't run. The engine will not run without the cam follower being between the hash marks or further. Race you want to see the throttle rod collar on the throttle control rod as it contacts the pivot block (white plastic piece) when wicking the throttle correct?
 
It is usually not touching at idle.----Try giving that stop 3/16" clearance.----Oh --It cost no coins and very little effort to try that.--------One of those adjustments on an outboard that looks wrong when it is right.
 
I believe 1/2" is too much.-----Often that is adjusted so there is no clearance by novices.------Best have another look at the carburetor.
 
Notice something that is not shown in the FSM. My carb primer output has a T. One hose goes to a nipple on the carb feeding the throat on the carb. The other hose goes to the intake manifold below the carb a little offset to the starboard side. The FSM shows a "oil recirculation hose" going to it. Wondering if this is a previous owner thing or was there a service bulletin the showed the modification?
 
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