1996 115 Johnson will not idle

[coltigh]

I need some trouble shooting help. I had not run my boat in a month or so but it started up fine and we went out on the lake. It was running fine but when I tried to slow down the shifting linkage seemed to be stuck. I finally got it slowed stopped. I checked to be sure that I could go from neutral to in gear with the engine off and it seemed to be fine. But of course now I have a new problem, the engine will not idle. It starts great and runs at high rpms but if you shift it into neutral it dies. I have changed the plugs and wires but still have the problem. As a test, I set the idle to be at about 2500 rpms and it will idle but really rough. At this point, I could put it in gear but I have no power at the high end.

I figure that I probably have a couple of problems. I want to try to get the idle to work and go from there.

 

[tashasdaddy]

Re: 1996 115 Johnson will not idle

check your compression first. seeing this was a sudden incident. are you sure you are getting good constant spark to all plugs.you can take an induction timing light and put it on each plug wire to test your spark in each plug. idling at 2500 ain't good. don't shift it there, or you could take out the lower unit. get the idle down 1st. what do your plugs look like after running. dry , wet, brown. white, black? just starters. get back with results. and welcome to iboats, the university of outboards.

 

[coltigh]

Re: 1996 115 Johnson will not idle

Thanks for the info. I will give it a try. The boat is at my cabin so I won't be able to get back with results until Sunday.

 

[moderator1]

Re: 1996 115 Johnson will not idle

sounds like a direct link-N sync is in order if a cable has stretched or been stuck, removed, etc...

 

[jrw1295]

Re: 1996 115 Johnson will not idle

I have the same problem with an Evinrude Lark from the late 50's. Runs great. When I trottle all the way down to shift, it dies. Then I can shift into forward or reverse and restart. Is this a matter of adjusting a cable?

 

[coltigh]

Re: 1996 115 Johnson will not idle

Well here is the update. The compression is low in one of the cylinders. The manual says to correct this problem first and then go to the next step. Do I need to replace the rings in all the cylinders or just the one with the problem. Do I need to bore out the cylinder/s?

Thanks

 

[Silvertip]

Re: 1996 115 Johnson will not idle

What are the compression numbers. If they are within 10% of each other they are ok. If any are below 80 - 90 PSI the engine may still run ok but might be down on power. It is foolish to replace rings on one cylinder since the engine must be disassembled. It also depends on what the cylinder bores look like. If they are scored, rebore, new pistons and rings are required. If only one cylinder is damaged only that cylinder would need to be bored. As for the idle problem, since the shifter acted up, see what happened there first. Something bound up and apparently is holding the throttle linkage on the engine open. Disconnect the throttle cable at the engine. Remove the air box and see if the butterflies are fully closed.

 

[Silvertip]

Re: 1996 115 Johnson will not idle

JRW -- you are highjacking some elses thread. You should post a new message so we can keep better track of who is who.

 

[coltigh]

Re: 1996 115 Johnson will not idle

I brought the boat back from the lake to work on it. The compression numbers were 120,120,120, and 60. Pulled the head on the side with the problem. Part of the top of the piston is missing. The center of the ridge on the piston had been worn off by heat I assume. The cylinder itself actually looks fine. I definitely need to fix this before going forward. The rest of the pistons look fine.