130HP Johnson Ocean Pro Cutting Out at Idle

[Ian B]

My 130HP Johnson Ocean Pro 2-stroke outboard is frequently mis-firing and then cutting out at idle speed. This usually happens within 5-10 seconds of it being started. The engine seems to run fine at higher revs, but will frequently cut out when I try to accelerate rapidly from idle. I've checked the fuel system and it appears to be fine, but I suspect that it's a problem with the ignition system. Do I need to do the full list of ignition system diagnostic tests or is this a common problem where there is something obvious to check first?

The engine has 400 hours on it and has been regularly serviced from new. It had a new timing base installed at 160 hours due to the idle speed not coming down below 1500rpm, but otherwise has been faultless.

Any help would be appreciated.

Ian

[timmyt]

i suspect the carbs--they are to lean for a cold engine--when the engine is warm the mixture is ok

[Afishinado]

"This usually happens within 5-10 seconds of it being started"

Once it has its morning farts over with, it's fine right? If so, it is fine....

[Ian B]

I didn't explain the problem very well. If I get the engine into gear and above idle speed immediately after the boat has started it will keep going. However, even after a one hour run at cruise speed, when I slow back down to idle it will mis-fire and cut out, usually just as I'm approaching the jetty at the boat ramp. Just above idle speed i.e. when going at 5 knots in the harbour, it is ok. The idle speed setting is correct and adjusting it up slightly didn't improve things anyway.