Help! Engine dies once put in gear

[laborderobin]

I posted a problem about three weeks ago and have not had any responses. Doesn't anyone have any idea how to help? I have read several other threads and have tried everything I can think of. I have a 40HP
Johnson (1976) on a MonArk boat. It has ran great in the past several years. Recently it started "cutting out" in the water and now in will die once it is put into gear. Starts and idles great but once it goes into gear IT DIES. I have cleaned the carb, even took it apart and it looked great. New bulb on tank, engine getting fuel because idles perfect. I just do not know where to look from here. Reading about the gear case now, guess that will be next. If anyone can help me, I really would appreciate it.... I really want to get out of the house and do some fishing this year.

Sorry this post is a little longer than most but wanted you to understand that I am DESPERATE!

 

[raczekp1]

Re: Help! Engine dies once put in gear

hi.
Can i ask you to post some pictures of your engin block, from left and right side,especialy carb trotle link with timing plate

 

[Sixmark]

Re: Help! Engine dies once put in gear

Better yet , if you could supply the model number

 

[jonesg]

Re: Help! Engine dies once put in gear

Possibly only firing on one cyl, use a timing light to check, better yet go to the auto store and get a $12 spark gap tester, set gap to 3/8th inch and test for spark.

Read the FAQ files.
http://forums.iboats.com/showthread.php?t=299680

 

[jtexas]

Re: Help! Engine dies once put in gear

... I have cleaned the carb, even took it apart and it looked great. ...

This implies that a carb can be cleaned without disassembly, and that you can tell from visual inspection whether it is clean. These are both myths.

You can't clean or see into the tiny passages where fuel has to pass. Follow the "carb cleaning and rebuilding" link from the "top secret file" at the top of this forum.

But first, before spending any more time or money on it, do a compression and spark test. PSI should be about the same (within 5 or 7% or so) on both cylinders. Spark test as described by jonesg.

Just cause it gets enough fuel to idle in neutral, doesn't mean it's getting enough to idle in gear.

So if compression and spark are good, and the fuel line holds pressure, and there's no water or debris in the tank, and the tank vent is open and clear, and the fuel is fresh, and the spark plugs are the correct Champion plug gapped correctly and in good condition, then rebuild the carb again, with a new carb kit, following the directions in the thread referred to above.

You'll need to adjust the slow speed mixture screw (if equipped), and follow the link & sync procedure as described in your service manual. I highly recommend the factory shop manual.

keep us posted.

 

[laborderobin]

Re: Help! Engine dies once put in gear

Thanks for the advice.... had to go to town to get a spark plug tester, even though I knew one spark was dirty and one was clean. Tested it and sure enough the engine is firing on one cylinder. I had to get a special tool to remove the flywheel to find out why.... still working on it.

 

[jtexas]

Re: Help! Engine dies once put in gear

you don't have to pull the flywheel, yet.

swap the ignition coils... if the problem follows the coil, replace it and you're done.