2000 Johnson 50hp 2 stroke idle issues

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
I haven't gotten a satisfactory answer on the AOMCI website, so I'll try here. Recently bought a pontoon with the above motor and have not been able to get it to idle. I had to replace the remote control box as the old one had busted nylon parts and the fast idle lever did nothing. I’ve gone through the link and synch adjustments as outlined in the service manual, but I can’t get the engine to idle worth a darn. The fast idle lever works so I can get her started but when I push the lever down, the motor barely keeps running and I have to quickly shift and give it gas or she stalls. The idle screw is set as far as it will go and I’ve turned the wheel on the throttle cable to try and increase the idle, but no luck. Once off idle she runs fine. I've tried adjusting the slow speed settings on the carbs. Spec is 3.5 turns out. It's now set to 3.25 turns on both. I've adjusted as high as 4.5 turns out, and she dies, then leaned it to 2.5 turns out where she again dies. Other settings make little difference, and 3.25 to 3.5 seems best. This is the newest motor I've owned. If it was 40 years older, I would easily be able to get her purring, but this has me baffled. Any ideas?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,411
You have done a compression test I am sure.----What were the numbers ?-----Checked flywheel key ( timing ) on this motor ?
 

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
You have done a compression test I am sure.----What were the numbers ?-----Checked flywheel key ( timing ) on this motor ?

Since the motor runs fine at WOT, I haven't checked compression or pulled the flywheel. I'll bring my compression tester from home next time we come to the lake.
 
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