1999 johnson 35hp problems

[radiomanlm]

Hello,
I have a 1999 johnson 35 hp 3 cylinder that has been giving me fits.Last year it would stall out and we discovered if you lightly tap on the electronic module on the side of the motor it would straighten up and run o.k. I took it to a marine dealer and they confirmed and replaced the module and checked it out.They said the carbs needed rebuilt before it would run correctly again.Their rate was more than I had to spend so I found another dealer that charged less.Long story short he rebuilt the carbs and informed me that they were like new but he cleaned them and put in new kits anyway.It still wont run right.It runs on the middle cylinder fouls out the plug on the top one and the bottom one still looks new no gas on it nothing.compression is around 125 on all cylinders spark is good and if you slightly choke each of the carbs with your hand gas is present in the front of them.Is there something Im overlooking or is there a common problems with these engines that would cause this.
any help would be appreciated.
thanks

 

[jbjennings]

Re: 1999 johnson 35hp problems

Your compression is great so no doubt you'll eventually get it running really nice.
I would get a $6 spark tester from autozone and see if you have good spark on all 3 cylinders (it'll jump a 1/4 inch gap with nice blue spark).
If so, then I'd check to see that all 3 carbs. are synchronized properly (your mechanic should have seen to this and probably did unless you just took him the carbs that were off of the motor). Then again, I've never worked on one of those 3 cylinder OMC's so I don't even know how the synchro works on them.
IF you're getting good spark, though, I believe with freshly cleaned carbs. it should run if they're synched right with the spark.
JBJ

 

[radiomanlm]

Re: 1999 johnson 35hp problems

Thanks for the ideas.When you pull the plug wires it has a hot blue spark that arcs close to an inch.I will have to look into the synchronization issue some more.I dont know much about this engine yet.I always ran older ones,but im learning slowly a few hundred$$ at a time.Any and all Ideas are welcome and thanks for your post.

 

[tashasdaddy]

Re: 1999 johnson 35hp problems

get the service manual from the dealer or here.

 

[radiomanlm]

Re: 1999 johnson 35hp problems

Hi,Just wondering if the synch. would cause this type of a problem. my mechanic thinks there may be a bad seal or something in the divider behind the carbs that is letting it get fuel from other carbs and keeping it away from the bottom cylinder.Anyone ever heard of this?He says he has seen this problem on mercs. before.He is really sharp on mercs but does not work on many ev/johnson products.
Thanks