KR-1S.co.uk Forum

back in the 90's I had a Bob Farnham tuned KR1S, one of the mods was to slot the ignition backplate in oder to advance the ignition a touch. Is there any merit it doing this, and if so, by how much?

i have done it and i think elf had done it at some point. i just slotted the pickup as slotting the backplate is tricky on the kr. does it work?? i dont know but a dyno or someone who has tried on a dyno back to back will have the answer. it should feel a bit more lively as it advances the static timing but in all honesty i could tell off the bum dyno. i think jetting my bike proper would give me more power in that it would be noticeable tbh.

could you tell me by how much you advanced it (its so long ago I cant remember), I used to set it with a dial guage in the cylinder head

on my "Heiden-tuning" engine (a dutchman), I also need to advance the ignition.

he said to advance it by 2mm (piston travel). run it standard now though, since I don't race anymore with it and don't need the last HP.

tbh scooble i havent set it up by any means. i just opened the holes as much as i could (2-3mm) and moved it accordinglly. i will get it on a dyno and play about with it while the jetting is somewhere near. i use v power shell with 50 50 navgas but have ran it on v power with no problems. thats with tz pistons/head profile.

I have previously sloted the pickup coil and moved that to advance the ignition. It does work but you can't get enough advance using this method as the engine could do with even more. Since I gone Zeeltronic programable ignition I have reverted back to a standard pickup coil with a more advanced curve..

what is best ignition timing using stock items, I am altering stock components to allow for adjustment.

with modifications looks like I can get upto 10 degree advance but would like to know if anybody has a good base advance which works.

I once read on McDizzy's pages he always tries to tune the engines in a way it doesn't need more advancce (when using the same fuel). In a way it made sence what he said.

just giving this as information

Advance is there to give the mix time to burn. The better the mix the less advance you need. My two pence worth is run your engine with the least advance you can and avoid all the associated problems - and there are plenty.

standard ignition timing is set by the manufacturer as a 'safe' setting in order to compensate for differences in manufacturing tollerances and differences in fuel.
The Minimum ignition advance for Best Torque may not always be what the manufacturer set it to though, so there may be some room for optimisation, but the risks increase with each degree of advance.
I one had a prototype engine destroy itself on the dyno once when it got so unstable that it ran away with itself even when the ignition was cut which eventually ended with it putting a 'leg out of bed'

sounds a bit dodgy to me

If there's no need for ignition alterations then what's the point of the ignitec or zeeltronic programable units?

If there's no need for ignition alterations then what's the point of the ignitec or zeeltronic programable units?

I heard it was possible to do a similar mod to the RGV250 which replicated the effect of the F3 ign box.