85 maximx no spark on 2&3

I just rebuilt my 85 maxim x 750. It wont spark on 2 and 3. switched wires going to 1&4 coils to 2 and 3 , and it now sparks on 2 and 3.

pick up coils both pulse when I put the meter to them and crank the engine. They also measure within spec.

I have continuity on both sets of wires from the tci to the coils.

This bike ran before it was torn down. When trying to start for the 1st time I had to boost the battery as it was getting low on power.

Is there a chance the TCI is damaged?

 

Sounds to me like a bad coil

 

There is no evidence of that. When you switched primary wires to the other coils the 2/3 primary fired the 1/4 coil.
Test the 2/3 coil primaries and secondaries. Remove the plug caps and check for corrosion at the wires, and check the plug cap resistance seperately from the secondary coil.

 

Long time ago I had problems with the cables what happened was the coil was ok thing was at some point I didn't get spark changed cables from side to side and had spark...It took me a while to realize that cables in the side I didn' have spark was kind of short therefore every time I plugged those cables the came loose and didn't have the continuity to make a spark...
I had or have, not sure a bad TCI. What happened is that the bike was running like it had a really bad problems in the carburator, too rich and off tuning...cleaned the contacts and now is running much much better...I need to make a long ride to see what happen if TCI gets hot which I don't know if that heats up

 

ok. had tci tested yesterday on a running bike. Tci was faulty as it would not fire 2 and 3 on that bike also.

So...I restored this bike. Completely stripped and powder coated the frame and painted the engine and removed the wiring harness in the process. Once assembled the bike wouldn't fire on 2 and 3. Switched to the TCI from my donor bike and again, it wouldn't fire on 2 and 3. switched primary wiring from 1and 4, to 2 and 3 and had spark at the spark lugs.

As the bike would not start, I boosted it with a battery pack as the battery went low. Is this the cause of the failed TCI? I have one more but cautious to install it until I am certain it wont get damaged.

 

COIL.

CHECK THE FAULTY COIL.

Primary resistance.
Secondary resistance (plug caps unscrewed from the wires).
Plug cap resistance.

 

coil primary are 3.6 ohms
secondaries are 14000 ohms

this is on Dyna coils DC1-1

I want to install the new TCI, but I am hesitant as I want to find out why the last one failed. Any ideas what to check for.

 

I have to check my tci on tuesday...seems mine is original and 31 years old...besides that could be a solder point loose or a faulty contact or just that contacts are not clean...

 

I've never had a coil die from jumpstarting

 

update.
I checked all the wiring , coils, etc and found no problems. Installed my last tci and bike sparked on all 4 spark plugs and started up. I took it for a 50 mile ride and everything is good.

Still uncertain why the TCI failed. One was from my donor bike which may have been bad to begin with.

 

Glad to hear the bikes is running. Not sure the fail Im having but have to do with the tci which I'll check in soon for loose contacts or something not in place.

 

Cool. It's good to be wrong sometimes. My bet is a bad solder joint or a trace that lifted from the board. Might be a cap that failed though. Worth deporting tohave a look.