9.9M 682C no spark? where to begin?

[brc1981]

Got my first boat this spring and have been working to restore it to a decent condition. 14ft Fiberglass semi-v w/ Mariner 9.9M. Should work out well for fishing once I get everything in good working order.

Laddies previously identified this motor as being a 1982 model.

Here's my problem. I've taken it out 4 times this year fishing and each time motor will start and run great for about an hour and then it'll miss out for a few seconds and just die and won't start back. After a few hours it'll start back and my run for a a while but will eventually do the same thing. At first I thought it was the plugs so changed them and same thing continues to happen. Thought it was bad gas since part of my tank was left from last year, so I got new gas (mixed 50:1). Still same thing happens. Fuel filter is clean. Motor just acts like its not firing.

Luckily, my trolling motor has been able to get me back to the dock.

Previous owner used it past 2 summers without any problems and took proper care of the engine in the off season.

I have ordered a Mariner repair manual, and am waiting for it to arrive. Thought some of you might be able to give me some suggestions about where to start. How do I check to make sure the plugs are firing?

Thanks

 

[Laddies]

Re: 9.9M 682C no spark? where to begin?

You need to test the engine for spark on both cyls with a spark gap to mke sue it has no spark as a stuck inlet needle in the carb won't let it fire also. The bad thing is if you don't have spark the only test I can find is with a DVA.

 

[zaroba]

Re: 9.9M 682C no spark? where to begin?

is it possible that its overheating?

i had gotten a really old lawnmower last summer with a really bad engine and while using it without the flywheel cover on it it would over heat and stall after about 15 mins of running and refuse to start after that. it would turn over, but would immediately stall again. but with the flywheel cover on, the flywheel blew air over the header and block to keep it cool and it would run with no trouble at all.

 

[brc1981]

Re: 9.9M 682C no spark? where to begin?

overheating could be a possibility I guess... I'm getting a good stream of water out the back, but do plan to change the impeller since I don't know when the last it was changed. I've ran the motor with and without the cowl and didn't make any difference.

 

[Faztbullet]

Re: 9.9M 682C no spark? where to begin?

Does your engine have a single coil with 2 spark plug wires or 2 seperate coils? If single your have a CDI unit and just a DVA test as Laddies said. If 2 seperate coils it is a points style ignition with condensers and charge coil under flywheel. A 682c is most likely CDI driven.

 

[brc1981]

Re: 9.9M 682C no spark? where to begin?

Does your engine have a single coil with 2 spark plug wires or 2 seperate coils? If single your have a CDI unit and just a DVA test as Laddies said. If 2 seperate coils it is a points style ignition with condensers and charge coil under flywheel. A 682c is most likely CDI driven.

It has the CDI unit. I'll have to look into finding somebody that has a DVA I can borrow...

 

[Joe72]

Been searching for this diagram for a long time, would you have the specs on testing this ignition and the proper procedure for doing so? I have an 82 9.9m serial# 682c s 058482 . I have a DVA I just purchased just need pointed in right direction. Thank you in advance sir!