KG 7 Runs Rough

[slim60]

Last year it ran great, then winterized. This year it runs on one cylinder and then two intermittently. Iv’e cleaned and set the points. New NGK B6S plugs. They are damp but look fine. Used the ohm meter on the coils and condensers. Removed the carb cleaned it. Is there anything else I should check? I hate pulling that flywheel again.

[fisherman6]

Could you have a bad plug wire or boot leaking voltage or arcing to ground somewhere? Might be worth changing the words if they haven’t been changed in a while. Bad plug wI respect are not always apparent.
-Ben

OldJohnnyRude on YouTube

[slim60]

New copper wires.

[dave-bernard]

Bendix or phelon ignition

[slim60]

Bendix Scintilla

[dave-bernard]

They can be problematic. if you can find the parts change over to Phelon. check your crank seals . good luck.

[billw]

New or original coils?

As a test, close the plug gap down to .010 to .015 and see if low speed run quality improves. Also try to determine which cylinder is dropping out. If the run quality doesn’t get better and the problem cylinder is #2, then maybe you have a crank seal problem. If it does get better, you may have an ignition problem and/or a weak magnetic rotor.

I forget which motor it was, as it was a long time ago; but I had a Bendix Merc that did the same thing. It had all new everything. I ran the plugs at .010 and it ran fine. Not saying it’s right; but sometimes with Bendix there is just no winning. I always thought it was the rotor but never proved it.

Long live American manufacturing!

[Tubs]

A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.

• This reply was modified 7 years, 2 months ago by Tubs.
• This reply was modified 4 years, 11 months ago by Tubs.

[slim60]

Thanks Guys; Two years ago new coils, condensers, and copper plug wires. I cleaned and set the points to 0.18. Then spun the crank with a battery gun for ten seconds and got a good steady 1/4′ spark. Installed flywheel and squirted fuel in the intake. Roped it over. Both cylinders hit. Installed carb and squirted fuel in throat. Hit on both again. Installed gas tank and it ran good after a few minutes. Idles smooth. Even while breathing some of it’s own exhaust. Now it needs a good run on a boat. I have a Lund 12′ so I can only dial it in on a smooth day. Last year it pushed my Alumacraft to 24 mph. I think it’s just a recurring fuel problem. Thanks again.

[slim60]

quote :

Re:Looking for ideas – Bendix-Scintilla magneto 2 Years, 5 Months ago Karma: 36
K series flywheel type magnetos having contact
point opening .018” stamped on stator plate should be set to a basic clearance of .015”. A tolerance of
± .003” is allowable. The .018” stamped on the stator plate is the maximum point opening and should not
be exceeded.

Thom, the above is from a scintilla factory document back in the day. As you noticed, reducing the point gap to .015 is actually the correct setting, but only for those mag plates stamped with an .018 on them. Gotta love early mercs.

This has solved my problem with this Bendix mag. Just thought I would pass it along. Now do any of you Merc guys have a particularly favorite spark plug you use?

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