Runs great at cruise, lousy at idle and slow.

[Kymasabe]

My '83 Johnson 60HP 2-cyl is acting up again. She doesn' idle very well, idles rough, trying to get thru no-wake zones is a coughing, shaking, sputtering experience. If I give it a little throttle, is better. More throttle = better running. She runs GREAT at cruise speeds and full throttle.

Any DIY tips before I drag her to the dealer...again.
Plugs are only 20 hours old, has new solenoid, powerpack, fuel/water seperator. Carbs were removed and boiled a few months ago...by a Johnson/Evinrude place no longer in business.
Should I DeepCreap it and replace the plugs?

 

[HighTrim]

Re: Runs great at cruise, lousy at idle and slow.

Will pumping the primer bulb pick it back up again? What about spraying pre mix into the carb throats? Choking it?

 

[tashasdaddy]

Re: Runs great at cruise, lousy at idle and slow.

i think you need to clean the low speed jets. or you float needle is sticking open, partially flooding at low speed.

 

[Kymasabe]

Re: Runs great at cruise, lousy at idle and slow.

Tashasdaddy,

You know what, the low speed jet thing sounds like it might be it. It reminded me of another condition that the motor has. After I've run it for a while and slowed down, motored slowly into someplace I want to fish, then later restart the motor..it'll barely run. Will bog out and stall if I give it fuel. I have to rev the engine quickly a couple of times, what we've been refering to as "clearing it's throat", then stick it in gear and it's fine.

Is the low speed jet thing something that a decarb process will cure with all that SeaFoam going thru it...or should I hose down the carbs with DeepCreep...or is this a bring-it-to-the-shop thing?
If I can't treat it chemically, I'm a little uncomfortable digging around mechanically.

 

[HighTrim]

Re: Runs great at cruise, lousy at idle and slow.

If the jet and carb need cleaning, there is no other way than to remove the carbs and bath/rebuild them properly, removing the jets for proper cleaning.

Something you can do yourself, a factory Service manual will help tremendously.

http://www.meegsonline.com/tmd/TMDsVideoChronicle2.wmv