14 replies to this topic

[stump magnet]

ok how i know this topic has been thrashed about a few times already but just want to clarify how much you think i should retard the ignition, im a half decent intermediate rider with very little cartilidge in my right knee (easier starting is therfore a plus!) plus i like to ride the power right of the bottom, and have already fitted a slow throttle, have just removed the flywheel and was wondering if 6mm anticlockwise might kill it off too much? would 3mm be better, anyone else moved theres 3mm and noticed any difference or was 6mm needed, cheers all

[arun1664]

I asked the same question myself, see here:

http://www.trialscentral.com/forums/index....amp;hl=ignition

can't comment about 3mm but 6 seems to work fine on my 2001, softer power and easier to start

Hope this helps .... Mike

[ScottT]

I've just done this on my 04 250, I retarded it as far as it would go, much better now but to be honest its a 10-15min job, just fully retard it then ride it, then slowly advance it till you find the right point.

[Neo]

ScottT, on Apr 17 2007, 07:40 AM, said:

I've just done this on my 04 250, I retarded it as far as it would go, much better now but to be honest its a 10-15min job, just fully retard it then ride it, then slowly advance it till you find the right point.

Watch out!!....your bike may start to over heat!!

Best of balance.

Neo

[ScottT]

Neo, on Apr 16 2007, 11:15 PM, said:

Watch out!!....your bike may start to over heat!!

Hi Neo, How? Can you explain why it might start to overheat, i might be having a blonde moment but i cant think why this would happen.

[Neo]

ScottT, on Apr 17 2007, 09:12 AM, said:

Hi Neo, How? Can you explain why it might start to overheat, i might be having a blonde moment but i cant think why this would happen.

All I know, from reading past Postings on TA and TC, is that if you reatard the the timming too much the bike can run really hot. Someone did expalin the reason, but I can't recall it now.


Best of balance.

Neo

[copemech]

Glenn, 3mm works fine just to "knock the edge off", a difference you can tell, but not too much.


If you slow the timing too much, there is also too much unburned HC in the exhaust which tends to overheat and lead to problems!

Edited by copemech, 17 April 2007 - 03:22 AM.

[stump magnet]

copemech, on Apr 17 2007, 12:41 AM, said:

Glenn, 3mm works fine just to "knock the edge off", a difference you can tell, but not too much.


If you slow the timing too much, there is also too much unburned HC in the exhaust which tends to overheat and lead to problems!

thanks mark just what i wanted to hear will stick to 3mm

[stump magnet]

ok mark, i have moved the plate 3mm counterlockwise and started the bike, the tickover was much higher so screwed the tickover screw out till it was ticking over a bit slower but a bit lumpy then turned the "GAS" screw in 1/2 turn from 3 turns out and all is ticking over nicely, then read on RYP's site that the tickover should be slower after retarding the ignition? does what ive desribed sound right to you? cant try thr bike till sunday in the event, i have moved the plate the right way havnt i?
(i stamped a mark where the centre of the top bolt is as stock and moved the plate till the bolt was between the new stamped mark and the stock stamped mark which is approx 3mm counterclockwise so it is the correct way i think!)

Edited by stump magnet, 18 April 2007 - 05:56 PM.

[copemech]

Glenn,
Seems all is well, I think mine did the same thing as I recall! May just go to show that the base timing is better that way in the lower revs. Possibly limiting the extreme upper end advance. The Leonelli will rev about 2000 revs higher than the old one! Not that you may need to go there!
As I recall, that note on the RYP site was written a while back, when the Ducati ignition was in use.

Can you not blip around in the driveway or street at home?

Running the mix screw in as much as possible has a smoothing effect as well, depending upon the day. What #pilot jet are you running? Sounds as though you are in the correct range.

[copemech]

I should add that the relationship in stator plate movement to ignition advance(BTC) is NOT linear and should not be confused due to the rotational geometry of the motor.

In an effort to keep things simple, that means that the initial 3mm of stator rotation has roughly twice the effect as an additional 3mm rotation, or in rough numbers 3mmBTC(standard), 2mmBTC, and 1.5mmBTC.

Below that, thing just do not seem to work well.

I have not degreed things out exactly of late, as I am really not concerned with the numbers as much as how it works, and 6-7 mm rotation on the plate seems to be about max allowable as far as retard goes.

Now as far as advancing for high altitude conditions goes? I really do not know. I am at about 500ft MSL(what is that, 150 meters?) above sea level here. So 0-1000ft variences apply, which are negligable. Trials bikes really are not GP racers, so they don't care!

[stump magnet]

thanks mark not sure what pilot im running as havnt touched it from standard uk spec, seems to run fine. have orderd a new iridium spark plug NGK says 0.6mm (0.025") gap this sounds right to you?

[copemech]

Glenn,

I do not think you would have any problems running the Irridium plug at .023-.025, but is a RESISTOR plug!

On the very limited output ov the system, to me it sort of defeats the purpose.

I prefer the BP5EVX non resistor Platinum, and have run them at .027-.028 without problem.

As they are no longer available here, see if you can find some, as those places over there do not want to ship to here.

In sparkie tech, it means having minimal electrical resistance and maximum electrode exposure and flamefront propagation in a system that makes the minimum required output and give maximum resistance to fouling!

And yes, they run better off the bottom as compared to stock!

Hope that makes sense to you!

[Essex Rider]

im ordering a few of these!! which i think are the same as what mark is talking about....

[copemech]

That's the ones!

Do you think you could send me a few so I can you send the Paypal?