KG7 Coils

[slim60]

Last year I installed new coils and condensers, cleaned the mag plate with brake cleaner, cleaned the points with acetone and it started one pull but had intermittent spark on the bottom. Went back and cleaned, switched parts. Same misfire on the bottom. I did solder the plug wires to the coils. I used a heat sink and the actual soldering took about ten seconds. THEN I read a post saying that soldering will destroy these coils. My question is if I did in fact do damage wouldn’t the coil be completely dead?

[dave-bernard]

I assume you have a bendix system. dose it loose spark or drop the bottom cyl? if drop then change the bottom and top crankshaft seals.

[slim60]

The bottom cylinder only has intermittent spark. It ran good the first time in the tank. I mounted it on the boat. It rained the next morning and that afternoon it started on one cylinder but the second cylinder kicked in at 3/4 throttle. Then I began rechecking ignition.

[dave-bernard]

add a ground wire from the mag plate to the block and try.

[jeff-register]

Get an ohm meter & read between the spark plug lead & ground the other lead. Scale set on 5K If you have around 3500 ohms or so look elsewear for the misfire. On the back of the mag plate you will find two screws, tighten them up a little but not too much for throttle lever still works. Pull the flywheel & check your points gap thru all the throttle advance ranges. If the plate has wear the points gap may change causing misfire. It may be a dirty idle jet screw not letting fuel pass equal too causing a misfire. Those are tiny jet holes & clog easy.

[slim60]

Thanks Dave and Jeff. I cleaned and checked the points paying attention to the insulators. Checked for mag plate wobble and switched condensers. Then attached the spark plugs to the gas tank mounts with a jumper wire. Slowly pulled it over with a rope and watched it spark 3 times per pull. Then I added a ground strap today. I didn’t find the right compression fittings for a 1/4" fuel line. I could use some advise with that. Otherwise I see no reason why this thing shouldn’t start. I’ll clean the idle jet tomorrow. Just need a fuel line and I’m good to go.

[billw]

quote Slim60:

The bottom cylinder only has intermittent spark. It ran good the first time in the tank. I mounted it on the boat. It rained the next morning and that afternoon it started on one cylinder but the second cylinder kicked in at 3/4 throttle. Then I began rechecking ignition.

How are you checking the spark? Are you using an open gap tester? I find that Bendix systems can reliably jump 3/16" and a really ideal one can sometimes make a 1/4". (Bendix ignition is kind of a joke. I may have had a bunch of weak magnetic rotors; but this has been my personal experience with many of them.) If you’re using inline, neon checkers, be advised that if the cylinder fouls out, like from water drops from a bad crank seal or over-abundance of fuel, the neons will go dim, as if they have no spark. This is because the voltage to fire a fouled plug is a lot less than to fire a normal one, like 2000 vs. 7000 and up.

People will gasp; but sometimes out of desperation, I have closed the plug gap to .015" and the result is a fine-running engine.

Long live American manufacturing!

[jeff-register]

Slim,
As you face the carb looking at the front of the motor on the right side it will have a small brass cap screw. After the screw is removed you will find another slotted brass screw & long tube. That is your idlle jet that picks up fuel from the bowel & sends it to the main opening. Make sure there is a idle jet washer under the jet where it seats against the carb body. If no idle jet gasket is there it will not draw fuel & will not idle. Good luck finding the gasket without not buying a carb kit. Be sure not to turn over& lose the carb gasket out of the carb body too. Clean & refit the jet into the jet well. Try to restart again.

[slim60]

I finally got my parts and cleaned the carb and idle jet. It was hard to start but got it dialed in and idles good. That dirty carb sure fooled me with all the signs of intermittent spark. It’s not easy because of the poor water circulation in a test tank. Took it out on the lake and it was hard to start again. Had to play with the choke for a while but after a few minutes it ran good. Actually this thing SCREAMS. I’ve never gone this fast on a twelve foot boat. Well I ran the motor out of gas after eight laps around the lake. I did hole shots, idled, WOT and it did very well for the first run in twelve years. There might be some tiny crap floating around in the carb so I’ll keep using Seafoam with the fuel (12 oz TCW-3 per gallon). Thanks Dave and Jeff; Slim

[dave-bernard]

any time. 1 914 three one 0 70 eight six.

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