94 Johnson gt200 rough idle

[49golfr]

Had motor rebuilt and broke it in as directed. Motor runs great on plane. Good hole shot and top end. Problem is after it is run for a while. Shut it off 30 minutes to fish then it is hard to start and idles rough when in gear. Idles better in neutral. At the ramp idles rough in gear then dies when I try to drive it onto the trailer. Idle speed in gear is around 650-750 rpm. Wondering if this is too slow. Also wondering if plugs are fuel fouled due to double oil for break in. Thanks.

 

[ezeke]

Re: 94 Johnson gt200 rough idle

650 idle in gear is correct on the warm engine. Be sure that the thermostats are functioning properly - take them out and check the seats.

If you find the plugs are fouled, the rest of the firing chambers will also be coked up and you will want to do a decarbon treatment.

Use the schrader fitting on your primer solenoid for your de-carbon, it makes the job really easy. Then add carbon treatment to your fuel all of the time. http://shop.evinrude.com/dyn_prod.php?p=763644&k=116692

You can use that fitiing on the BRP/Evirude treatment, but it also will work on the SeaFoam Aerosol can.