GT 380 - No spark on left sylinder

[Nissern]

It started with backfire in the exhaust and cab, i so i desided to go for accent electric ignition.
Started it up and i was so happy the fireing was gone but no wonder, the left sylinder didnt fire, doh.

Sendt some mails to Uwe, for some intructions. He said the ohm the coils. they seemed fine OHM vise.
Later that day after after dismantling the exhaust, i saw the one one piston ring was missing.
So i ordered new pistons, mounted those to day hoping it would help but nope Did get a better comp =)

New mail to Uwe asking why i had spark when tuning in the key.
No worried there cus that was normal.

So why dont i have spark on left cylinder?
Ohm on coils seems right.
Coils have the power as Uwe said.
And like i said it have one spark right after turning the key, but not when running.
It runs on 2 cylinders while i have the left plug grounded in the cooing ribs. But no spark.

Could i have a bad coil? Plug cap?

Im so confused right now.

Thanks

[GTandcbr]

Hi.
First thing to check is the nylon/plastic gear behind the accent disc. These have a habit of breaking up or just cracking onn the 380 and cause the symptoms you report.
If the coils have been measured with a multimeter and have 5 ohms then the coils will be okay. You need to go through the loom connections one by one to make sure they are good.
Remove the plug caps and trim the HT lead a few mm and screw the caps back in.
Check the plugs are good and preferably not resistor type and the same goes for the plug caps as well.

[Nissern]

Yes, could be the nylon gear.
But if i got a bad nylon gear, wouldent that effect all 3 cylinders? Not just the left one.
And i was aware of the nylon gear issue when mounting the ignition.
But then again, the gear could have a crack or somthing.

Is it much work, cheking the nylon gear?

[GTandcbr]

I have not tried this job myself maybe someone who has can help? I have heard that a faulty gear can and has affected just one cylinder. You need to examine it closely with a magnifying glass as sometimes it is not obvious maybe just one tooth missing.

[karl pa]

Is it much work, cheking the nylon gear?

To check nylon gear you must remove clutch cover, it will come off with the cover. You need to line up marks for timing when putting cover back on.
The nylon gear drives the points cam shaft, so I don't see any way it can affect just one cylinder without affecting the other two, if something jumps on one it will jump on all three.
If the points cam shaft bearings have play, it can affect points gaps, causing issues but shouldn't affect electronic ignition.
I would look for bad connections or broken wires. My 73 750 was backfiring through exhaust and carbs, after a long troubleshooting I found a points wire rubbed through under the engine and grounding out changing the ignition timing.

[Nissern]

I'll start checking the wires.

Good this anoys me, its soon winter her in Norway and it would be awsome to take a small ride.
Just to feel the new Higgspeed pipes

I'll do a post later when ive solved it

Thanks

[Nissern]

Would it be vise to try another coil?
whu got the same "stats" ar the original one.
Cus wierings looked all fine

[GTandcbr]

Good thing to try is swap one of the bikes coils over. Has the problem moved to another cylinder?

[karl pa]

Cus wierings looked all fine

Did you test wires to be sure copper isn't broke inside insulation?

[Nissern]

Good thing to try is swap one of the bikes coils over. Has the problem moved to another cylinder?

I did try swap over from center to left. And left did fire, but center sylinder was dead.
So i know for sure the coils are all good
New mail to Uwe at accent

But the left cylinder did missfire alot, like it did before i installed accent ignition.
Carbs have been cleaned, with fresh jets.
Could crank seal cause missfire?

Any ideas why i got missfire?

One step forward and then one step back ;(

[GTandcbr]

So you say the problem DID move when you swapped the coils so surely that means you have a faulty coil? The left one you moved to the centre caused the same misfire?
These motors will start and run with faulty crank seals. I dont think that is your problem.

[Alan H]

But the left cylinder did missfire alot, like it did before i installed accent ignition.

Nothing to do with Accent then. So;
Bad connection between battery - fuse carrier + fuse - ignition switch - kill switch - coils.

Have you gone through EVERY connection and tested voltage at each point?
Low voltage gives weak spark = misfires and poor running.
Original issue could be the same as suggested, or even a faulty/dud capacitor or a weak spring on the points.

[Nissern]

Return the ignition back to Accent yesterday.
He wanted to have a look and he tought on hall (or whats it called)was defect.
So im guessing i wont be doing much with the bike this month.

Nothing to do with Accent then. So;
Bad connection between battery - fuse carrier + fuse - ignition switch - kill switch - coils.

Have you gone through EVERY connection and tested voltage at each point?
Low voltage gives weak spark = misfires and poor running.
Original issue could be the same as suggested, or even a faulty/dud capacitor or a weak spring on the points.
[/quote]

Im not going back to points.

Wierings look fine, and i got 12v+ on all coils.

[Nissern]

I dont think i got any fuse. And ive seen trough most of the wiering.
Would the fuse be right after battery?

Regarding killswitch, havent been looking at that yet.
How do i fix/check that?

[GTandcbr]

The hall sensors are little switches(one for each coil) and they are activated by little magnets which are set into the rotor. This fires the coil. The sensors are close to the edge of the centre hole in the accent disc. If the disc is not mounted properly the rotor may touch and damage one of the sensors. That is a possibility.