continous sparks at the plugs

[ir_joep]

Hi,

Today I took a look at my ingnition, suspecting it to be not so well timed. Anyway, I put on the strobelight and started the engine. The strobelight was more or less on all the time! I checked with a spare spark plug which was firing like mad on idle. When I checked the other plug it was the same. Mind you the bike was running and I was riding it a lot last weekend. (it was still a bit rough between 1500 and 3500 if you remeber my previous post).

What could be the cause.

This is were I am at the moment:
900 SS engine
Kokusan ingition from 750 sport
750 flywheel with 1 trigger lump
2 x 750 pick-ups (with a 2 large gap of <1,0 mm which I planning to adjust see what that will bring)

What do you think? Start looking for new Kokuan boxes?


thanks for any advise

Cheers Joep

[ducinthebay]

Can't explain the constant spark. Check that the system is all working well and the coils are properly grounded. An intermittent ground will do funny things, especially at a coil. A broken wire will also do funny things as it makes and breaks the connection.

Cheers,

[paso750]

I checked with a spare spark plug which was firing like mad on idle

What do you mean by this ? It will fire 800-1.000 times per minute on idle. Does it fire more than that ?

G.

[ir_joep]

…went to the workshop last night to check out the ignition again.
Keeping in mind the firing rate G is suggesting. I think G is right, how I earth can I see or count the sparks? I wish I could only count the revs by the sparks or signal going to the coil(s). I have an old electronic rev-counter for a car. I may wire that one in.

The tests did last night:
Exciting the pickups with a screwdriver resulted in a spark at the appropriate plug.
Turning the engine on the electric start (low rpm) revealed that there were not too many sparks but like it supposed to be. Strobelight shows the mark on flywheel at one spot. So at low revs every thing seems to work.


So a faulty diagnosis on my account. Sorry for all the sleepless nights I have cause to all of the forum members.

Set the pickup gaps to a 0,6-0,7 mm and checked the ignition timing. Put the engine back together. It still has some the same problems in the 1500-3000 rpm range.

Next steps:
re-check valves and valve timing
Balance weber

If that does not help:
Install digiplex which came with the engine originally (Still suspecting the Kokusan a little). Will need to do some rewiring though!

Thanks for your patience and you help

Cheers Joep

[higgy]

I think you are on the right track with heading towards the cam timing and carb tweaking.
You can do the digiplex but I don't see it making much difference overall.

For the weber on a 750 there are twos guys making progress that can lead you in the proper direction

jayh and jfiore and I am sure there are many others,not to slight anyone's efforts

[ir_joep]

Higgy,

Thanks for your uplifting words. There must be a big pot of gold on the end of this problem. But we keep on trying.

The digiplex is the only "spare" ingnition I have which was orginally with the 900 SS. In doing so I will have everything more or less standard (weber, digiplex and coils) for the 900 ss engine. That is the thinking at the moment.

Cheers Joep