83' Johnson 150 hp V6 high idle

Fazerfish

Recruit
Joined
May 11, 2009
Messages
4
Could anyone tell me what may be causing my idle to be so high? It also seems to have a skip in the idle only, not when I'm moving.
I just had the carbs rebuilt and the fuel pump rebuilt, and the mechanic and I thought it idled too high. He said it might be the starter solenoid, but I wanted another opinion. Regarding the skip, it sounds like, if it was my car, I would think a spark plug wire was arching somewhere onto the engine, thats what it sounds like at least. Happenes every 3 -5 seconds when idling.
Any help would be appreciated.

Thanks
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: 83' Johnson 150 hp V6 high idle

"He said it might be the starter solenoid" find another mechanic. all the solenoid is, is a electric activated switch, all it does is activate the starter.

i would start pulling spark plug wires with the engine running, (insulated pliers). if the cylinder is running, you will hear a decrease in rpms. no change that cylinder is not running. you then need to determine if it is spark, compression, or fuel causing the fault.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 83' Johnson 150 hp V6 high idle

You may have a carburetor lean sneeze. Not a major issue, but it is an indication that something is out of adjustment. Usually when the carbs are rebuilt, they should go through the process of sync and link, per the manual. If they were not properly "sinc'd" this could be your problem. This can be caused by a couple of things. The engine must idle with the carb butterflys closed. If one carb is cracked ajar slightly, it will introduce too much air and can cause a lean sneeze on that carb. If the throttle cam is still tight on the roller, they could all be ajar. Also, if you have too much idle timing, it can idle high and lean sneeze. I agree with Tas' comment. You need to find someone else familiar with the engine to work on it.
 

Fazerfish

Recruit
Joined
May 11, 2009
Messages
4
Re: 83' Johnson 150 hp V6 high idle

Thanks guys, if its not a major issue, maybe I'll wait til next year and bring it in to someone else. This is a project boat and I am only able to do a little at a time because of money constraints. One thing that kind of bugs me is the black oily stuff that drools down the shaft after it has run for a while. Comes from up under the engine somewhere. A guy at a local marine store said that it is typical for 2 stroke engines. Seems strange because I mix my oil in the gas tank, and this looks like used oil....
Thanks for the advice..
 

hoeser

Petty Officer 1st Class
Joined
Jun 18, 2006
Messages
253
Re: 83' Johnson 150 hp V6 high idle

If you are seeing oily drip along the midsection of the engine it is likely coming from the crankcase, especially if you are premixing. I had a similar problem with an 84' 140 Rude' and it turns out the guys that rebuilt it last did not put the individual screw o-rings back when they put the output shaft crankplate back in place, never dripped again after I rebuilt it. A properly sealed 2 stroke running a high quality 2 stroke oil actually "appear" pretty clean to the naked eye. The nose is a different story...
 
Top