Intermitent problem1994 135hp

Hi folks,

The motor is a '94 V-135 Black Max 2.0 ltr. It runs well at cruising speed but will occasionally stall at idle when put into gear and then have difficulty starting after stall out.
I changed the plugs and wires and fuel filters. I had the carb adjusted by a Mercury mechanic but it still does it. It has done it both warm and cold. I haven't yet done a compression check.
I'd like to troubleshoot this myself without taking it back to the mechanic so any input would be appreciated.

Thanks

Re: Intermitent problem

Was wondering if you ever figured out what the problem was? I am having the same problem with my 200 Johnson Ocean Runner.

Re: Intermitent problem

If the problem is only once and awhile it's going to be harder to trace. Having the motor run fine at higher rpm says its capable of doing its job except when it comes to idle.
I'd be looking for a problem in the idle circuits of the carbs. Cleaning or rebuilding the carbs may be needed.
Dan

Re: Intermitent problem

Beautiful place St. Michaels,love the crab house,I would rebuild carbs and check the fuel pump diaphragm,though if it is intermittent it is more than likely an electrical problem.However if you post on the Johnson/OMC page someone there that knows Johnston's will be able to help,man that icecream parlor

Re: Intermitent problem

Intermittent stalls at idle or when put in gear is often a fuel related problem. It could be a bit of old gas, a slightly clogged filter or a carb related problem.

The "mechanic" who adjusted the carbs should have suggested at least a cleaning - carbs do not go out of adjustment all by themself, so if they weren't fiddled with after they were set-up, tweaking a needle valve is just a short term solution to a problem that actually needs addressing.

Since you have changed the plugs/wires and filter you may want to try running some fresh gas with any of the "tune up" additives recommended for 2 strokes. Products like Seafoam or any of the generic "small engine tune up" juices may help if the problem is just getting started. However, if the problem persists it's time to have the carbs torn down and well cleaned...