1976 35hp idling erratically ????

[bukman]

My 1976 35 Johnson idles very erratically. At times it will increase its' rate while others, it will slowly die and stall. It also produces alot of pollution in the water while idling, which I wish I also could stop. Also, in order to start the motor when cold (first start of the day), I MUST crank the throttle up to the highest, in neutral that it will go. My question is...........would all this be alleviated with a carb rebuild, or do I have a pipedream?? <br /><br />Any and all help GREATLY appreciated, Thanx

 

[Joe Reeves]

Re: 1976 35hp idling erratically ????

The proper process is to trouble shoot the engine before you start throwing parts at it.<br /><br />Check the compression first. What is it?<br /><br />With the spark plugs removed, the second thing to do it to check the spark. Rig up a spark tester of some kind whereas you can set a 7/16" gap. The spark, at cranking speed should jump that gap with a strong blue lightning like flame... a real SNAP! Does it? If not, describe in detail what the spark looks like.<br /><br />If the above two functions of the engine check out as they should, I would assume that the carburetor is fouled, in which case, remove, clean, and rebuild it.