82 maxim bobber no spark!

hello folks. i started chopping my bike up a while back and am finally at the wiring portion. i haven't touched the wiring at all since it ran. i hooked up the stock harness and checked it all twice. im not getting spark at any coil. the wire connector to the coil is getting power, and the coils have about 3ish amps at the primary and roughly 20 at the secondaries. so i just need help. i figure if anybody here can give me and insight i'll whip up a build thread for everyone to read. the picture is my bike how it sits. ive gone through all of the little shit like fuses too. i got a new ignitor box today too and that didn't change anything. it may be bad or not the problem. im dying to make it go vroom so i can finish it! please help!

 

Welcome, nice hard tail mod. First put your bike info in your signature so everyone knows what bike we're talking about. Second, before you took the harness off, did you take any pics? You may have omitted something or hooked up something wrong.

 

The TCI need several things to work;
12 v power
Input signal from the pick-up coils
Output to the ignition coils
There is a saftey circuit that can dissable the ignition.
You need a wiring diagram and a service manual to check each part. Verifying each component seperatly will help determine what is keeping it from working.
If your bike ran before the mods were started I suspect the saftey circuit is the problem providing all the wiring plug connections are in place.

 

Pull the relay by the TCI box. On my 82 750 Max it is the safety relay. That will tell you if you have a bad safety switch. Mine fired after doing that, and I found the sidestand switch was the culprit.

 

Thanks for the suggestions! I have the haynes with the diagram and I plugged the sidestand switch in and tried pressing it while starting it and every way I could imagine. The bike ran great before the chop and I'm suspecting its something stupid like a missing ground. I made sure to not molest the wiring before I got it running again.

 

Start checking the wiring plugs to the TCI, pickup and ignition coils. Check all the grounding points that are made into the wiring loom. Since it ran before its probably something easy.

 

Make sure the ground strap is connected to the engine.

 

I have the engine ground strap clamped to the frame. I think that's where it was. I found the little ground that goes to the coil and hooked it up too a while ago. I swore it would do the trick!

 

I noticed in the last pic that you don't have any gussets where the backbone and down tubes meet the neck. You will need some to keep the frame from tweaking due to the motor torque. Also, if you omit the drive shaft tunnel, be sure to add a safety ring to protect yourself from a failed u-joint. Doesn't happen much, but better to be safe than have a shaft in your hind parts. :lol:

 

Oh that last picture was right when I was putting it together. The chainstays weren't evenwelded on yet. Look at the magnets. I have a pretty stout gusset at the heartiness now and I have a seat tube now too. Oh and I replaced my u joint with a piece of string so I shouldn't have anything to worry about.

 

Mother lover I meant head tube not heartiness! I hate autocorrect!

 

Good on the gussets. Piece of string?

 

Make sure that the heavy earth lead between the motor and the frame
is connected and clean. Check the kill switch as this cuts the power to
the coils to turn off the engine and may be shorting out.

 

so weird. i found and plugged in my headlight relay and suddenly i lost my headlight but i'm now getting spark to the number 1 cylinder. i'm dumbfounded. could i have burned up my coils when i welded on the mount with them attached? i'm quite sure it's the headlight relay too, according to the haynes diagram. 50 internets to whoever solves this! should i just start from scratch and do the minimum wiring diagram thing that eliminates all of the extra "optional" junk, like the turn signals, high beam, and all of the countless safety doodads. i can't wait til it's done so i can get some real details up here!