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Please help.....friends coming on Saturday to go on lake

I

ITSMEBOAT

New member
2002 50 hp Johnson 2 cycle

It got so it would not idle without stalling. I borrowed a pontoon trailer and pulled it out. The marine
mechanics in Hartwell are 6 weeks behind so I tackled it myself. Pulled carbs off and put in rebuild
kits. Replaced all hoses on fuel/oil pump. New plugs. When I started it on land it ran good but would
not idle less than 1200 rpm's. The idle screws are back at 2 full turns out as they were when I pulled
carbs. Not sure what spec's are.

It ran good first time out and ran smoothly at 5100 rpm and 2000 rpm, but when I tried to
dock and put in neutral it stalled. Would only start with advanced throttle but would not go
low enough to put in gear. After much effort I was able to start and slam in forward tied to the dock..ran great at 2000-3000 but once I hit neutral it went down to 1200 rpm and would stall. Hard to restart
and only out of gear at advanced throttle and with some surging from 2000-4000. Tank bulb remains
firm and I see fuel in filter so it is getting gas. This motor always started hard . Any thoughts
on possible fixes:
air leak
fuel hose problem
low speed needle adjustment
throttle linkage issue
Floats?

ANY help would be greatly appreciated. I need to get a service manual soon. This all started after the repair
on its maiden voyage as I returned to the dock and tried to idle.
Thanks for any help or advice you can give me. Don
 
I don't know the exact specs on this motor for idle speed, but out of the water you will definitely idle higher than when the motor is submerged. The lack of back pressure from the water lets it rev higher. So, 1200 on water muffs is about right. You should probably see about 600 to 800 RPM idling in the water. I would set the idle to about 1200 on the muffs then retry in the water.
 
If one of these motors is " hard to start " there is something wrong.--------------Start with a compression test.-----------Check and see if you hear the primer valve click when you push in the key.-----------Test run with a " known to be good " portable tank and hose.
 
Last edited:
racerone said:
Carefully inspect ignition system wiring on the ENGINE.--------------Look at all rubber plug in pins / sockets.
Click to expand...

I did but could not find any issues. I did go get a brand new gas line and hooked up to a
proven tank. It starts out of gear and moves up to 2000 rpm based on how much gas I
give it. After 10 seconds it surges to 4-6000 rpm and I have to pull back to neutral and then
it stalls or I have to pump it to higher rpm's to keep running, and more of the same
surges. What makes it surge like this?? How frustrating!!
 
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