82 Liquifire Ignition Coil Burning Up

[JDXpowered]

I have an 82 Liquifire with electric start.

I cleaned up and repainted this sled last year. This year I charged up the battery, cleaned carbs and when I went to start it, it just kept turning over no start. I pulled the plugs, no spark. While trouble shooting, I noted that it would smoke around the rear of the coil box. I put a spare coil box on it (the ones they don’t make anymore..., it sparked for a few turns then stopped. I put this box on one of my other sleds, and of course it now doesn’t work....

Does anyone have any idea what would cause this? Or what I could check? I am pretty worried about finding another box and don’t want to swap out anything for fear of burning up things.

Thanks

[AirborneX4Special]

I'm not an ignition expert but something of that nature would sure indicate a hard short in all things electrical. I tore a bad trigger unit apart one time and there wasn't much magic inside. Something must have gotten hot due to excessive loading and the plastic started to melt because there's just a couple coils inside if memory serves me correctly.

[nick80lf]

I agree seems like something is shorted. Inside the engine there are three coil: exciter, pulser and lighting. The battery is charged by the lighting coil. The CDI uses the exciter / pulser. Could there be something funny happening with the key switch that is putting battery power into the CDI circuit?

[nick80lf]

Maybe another quick check before pro ouncing the CDI dead.....unplug the harness from the motor (5-pin plug by CDI box) and pull it over by hand to check for spark. I wouldn't try starting it this way because you don't have an easy way to shut it off. Just away of trying to narrow things down.

[JDXpowered]

Everyone thank you for the reply’s. I went through the whole harness today. It was patched by the light connection to the hood. I took it apart soldered and covered well. Light connection at the light did look melted a little, but that damage looked pretty old so not sure that is related. Everywhere else looks fine.

I pulled the CDI box off and tried it on another sled that is pull start there is no spark. So I know I have two CDI boxes that do not work. I think I did change the key switch on this sled to one that looked more original, so maybe that switch is the issue? Is there a way to check the old 5 pin switch to see if something isn’t right there?

I did try to unplug the harness for the heck of it, no spark.

Is there a way to trouble shoot the exciter or pulsator coil? See if they are shorted? Or something?

[JDXpowered]

One more note on CDI, when I put the original CDI on the other sled with pull start, the one I took off it, it sparks well. The two that are from the electric starting sled do not work. One of these two worked for a few seconds when I put it on the electric starting sled, then it quit.

[AirborneX4Special]

On a side note, electric start wasn't listed as an option until 1983 on a Liquifire. Might your sled be an '83? Serial number would begin at 222,001 and build date in 1982.

[JDXpowered]

Key switch comment got me thinking, checking continuity on back of old switch, new compared to old,,,,, seems like new switch has continuity between the black wire and red wire. Old one doesn’t, new switch I think was from a am103286 or AM32686. Checking some more there terminals, seems like several are different.

Given that, it turns over fine still, headlight seems to light up when turning over so that seems ok. Is there a chance this messed up the exciter or pulsator coil? If so how do I check?

[JDXpowered]

Serial number 190271,,, checking it again, it is an 81, must have a kit? Or wrong engine.

[AirborneX4Special]

That's an '82. Must be a replacement engine or updated to electric start.

[JDXpowered]

thanks for the information

[nick80lf]

I believe the 82s were the first year the liquifire was preped for e-start from the factory. This basically consisted of a ring gear on the flywheel and the starter mount holes in the crankcase. E-start was a dealer installed option. Deere never had an e-start kit specific to the liquifire and you will not find it listed in the part catalog. Deere published a bulletin outlining how to modify the Sportfire e-start kit for use on the liquifire. From memory (if that is accurate) I believe the only thing you had to do was notch the battery box bracket for the gusset that the 81+ liquifire has in the belly pan.

About a year ago I was pretty deep into coming up with a home brewed e-start kit for my 80s. During this time I noticed the you need to be very careful with how these key switches are configured. Just because the switch has 5 pins doesn't mean it will work correctly. The major difference i noticed is that some switches connect battery power to the ignition in run mode (used for engines with distributors) and others isolate the ignition from ground in run mode (magneto ignitions).

Attached is an excerpt from the Sportfire service manual detailing the ignition switch pin out.

[AirborneX4Special]

I know my '82 has no crankcase provision for a starter but....no telling if the pieces and parts are original to the sled of course. Guys who have known original parts can jump in with their evidentiary findings since the endless capacity for nerdy data seems endless for me.

[nick80lf]

I ment to post this second image that is a piece to this puzzle but was sidetracked.

[wgrdafoe]

Make sure battery voltage isn’t finding its way to the cdi box.