MK1 ECU in MK2 engine, intermittent spark

[ptorresavello]

Hello everyone, my name is Pablo, and I'm from Chile. I have read a lot from this site, it has been very helpful for me, specially because this bike is uncommon down here, and parts are very very difficult to find.

I bought a working MK2 last year, I decided to paint the chasis, and when re- wiring my pgm died(entirely my fault), (NO SPARK)then I realized that my bike was running whit the mk2 pgm, but with a mk1 pv controller(obviously because the pv side of the ecu died). After searching a lot, I managed to find a working mk1 ecu, I rewired everything in the correct form, got rid of lighting and finally got spark, but the problem is that the plug just sparks once, I mean, if I rev the engine whit my hand in about 2 seconds interval, it always sparks, 1 spark for each pull, but if I crank the bike faster, the spark disappears.

By the way I checked the state of every component( reg/rec, coils, earths) I think they're fine. Anyways, if you could guide me to do this tests correctly again and make sure everything is ok or find the damn problem.

Hope you guys can help me, my bike has been abandoned all summer waiting for a solution.

[knackeredMk1]

Oh boy . That is a hell of a question .

I really don't know where to start.......

Obvious things on a standard bike would be side stand cut out and on/off switch. You don't know if the bike started out as a Mk1 and then someone grafted a Mk2 ECU on .

It's quite a feat of wiring if the bike started as a Mk2 and someone grafted a Mk1 PV controller on to fix a fault in the Mk2 ECU. I'm not even sure that is possible . I suppose it depends on which part of the ECU is faulty.......

You will find some testing procedures in the FAQs and in the AR manual that you can download.

The obvious start to a solution would be to get hold of a Mk1 wiring loom. LT might be able to help or ebay/Rinkya.

Good luck .

[ptorresavello]

I'm 100% sure is and original mk2 with usd forks, big black pgm original wiring loom, but adapted everything now to work as a mk1. Before the bike died, everything worked perfect, operating pv and it started almost every time with the first kick. i think the most probable cause is the signal sent from the pulse generators, could you tell me how to properly test this?. I checked the resistance of them according to the AR manual, and it seems ok, but I couldn't get the voltage right I think, it said 2.1v peak or above was ok, but the voltimeter didn't response at all, I don't own a peak voltage adaptor but now I'm going to try with another tester.

I will try to upload a video to show you the problem, if you don't understand it yet. Very low revs = spark ok, High revs= no spark

[knackeredMk1]

That sounds like either the generator or ignition coil is breaking down when put under load.

I can't give you any information about testing the pick ups. Others maybe able to help .

[ptorresavello]

I read an older post saying that the pick ups had to be moved in order to be at the correct ignition timing, this has nothing to do with my problem right?? I mean, the spark timing is another issue completely apart from the lack of spark at higher revs. By the way I got voltage now from the pick ups, not much as 2.1v, but not measuring it with the peak voltage meter.

The other thing I realized yesterday was if I disconnected 1 pulse gen, ( WHITE wire), the problem persists exactly the same way, but if I disconnect the 2nd( BLUE/ YELLOW wire), the spark disappears completely.

Is that normal??

[knackeredMk1]

I would think that if you are getting pulse they should be OK.

With regards to your question of normality - I don't know.

[Carbguy]

I had that same spark problem on my AR. And first i thought it would be my fault
Because i had the gear potetiometer not correctly installed. But even by fixing it it made
No diference. I manged then to clean the pickups from their rust, and so she startet again on
First kick. Maybe you got a similar problem?
Dennis

[ptorresavello]

thanks for the help, I will clean up all the stator rotor pickups system and see what happens.

[Carbguy]

I once got informed that ECU and flywheel must match... don't know if these could be a problem, too

[knackeredMk1]

'I once got informed that ECU and flywheel must match..'

That is correct, but I don't think that is the spark issue. How many holes on the flywheel .

It is possible that the 'new' ECU is faulty .

[ptorresavello]

there are 6 holes i the fly wheel, I'm trying to take it out, but a need a flywheel holder, any ideas how to make one or a way to take it out otherwise?

[knackeredMk1]

OK - You haven't got a Mk1 fly wheel. SO you need to get one of those if you are running it with a Mk1 ECU.

[ptorresavello]

but is that causing my problem?, or that is a completely different issue

that is a straight swap? any mods you have to make it fit?

[knackeredMk1]

If the issue is sparks dying at higher revs then the flywheel is not your issue but you will need to swap it if you want a reliable bike. The reason is the ignition timing is initially set by the lumps on the flywheel which the ECU then works with. You get ignition timing issues (running hot .....) if you don't match the flywheel and the ECU. Swapping the flywheel will help you towards getting it fixed and I wouldn't run the engine without changing it.

If the issue is not the sparks dying but ignition timing problems then swapping the fly wheel may solve the problem completely.

[ptorresavello]

Ok thanks for clearing that out, the spark dying at continuous rpm is my issue, I even pulled the bike for a few blocks to make it run in 2d gear with an atv to make sure of that. There's no spark at all when the bike revs constantly. In fact, I found out that the only way for the plug to always sparks continuously is when I give the kick starter very very short and quick pushes. But when I kick it strong, there's only ONE spark and no more, I mean, the plug ALWAYS spark when the kick starter comes back a few inches for a new push.