YZ100 ignition

[matcho mick]

just fitted 90/91 YZ250 external rotor ignition to Yz100K(internal rotor) using 81 IT175 blackbox ,have spark,how do i find timing reference point? use strobe 1st?,yz100 is .8 btdc,it's late, thinkings tad fuzzy  ,
ps idea is to "dumb' down motor for vinduro,(bloody IT175 motor is side port)

[matcho mick]

15 secs after head hit pillow,answer popped up  ::)papermate whiteout dotted the flywheel, indexed the case,hooked up the timing lite,back wheel a spin,hmmm tad advanced,flywheel off,retard stator,refit,& phaaarkkk the timing lite had shit itself,ggrrr,dragged ossa out loaded up & left for eurgowa,
ps weighed IT175 flywheel efffing 1.8kgs  ,YZ 800 grams,bit of difference

[matcho mick]

has anyone got ign timing specs for 83 YZ100 K,googled dutch guys blog,but methinks .8 btdc tad retarded??,

[matcho mick]

well it runs  ,sounds ok ,stlll nfi on timing specs,the YZ250 flywheels magnet seems to be continuous,a full circle??,it's only 5mm in depth too,maybe thats why pulse has a higher reading compared to IT's?,anyone got specs on 90-93 yz250'stators?,tia,

[matcho mick]

WTF,slotted the stator plate 25 efffing mm,still fires at "11am",which is where it was when i threw it on!, i thought the pulse (trigger) was the timing point??,can someone shed light on this??,(Lozza),ok i know the YZ250's on the left,& in this application it's on the r/h side running reverse direction,but  slotting the shit outa the stator plateshould have influenced the timing heaps,but has made no impression,so logic suggest the rotor which is indexed & hasn't moved (yet  ) might be it??,please explain,anybody??,  

[Lozza]

Hmmmm I dunno where to start parts from 3(??) ignitions? Without running them all on a test rig there isn't any real way of finding out what it will do. Spark timing will be controlled by the cdi the CDI will look for spike or dip in voltage as a reference.
Running the flywheel in reverse could be producing a dip in voltage and the cdi needs a spike or vice versa.

I see a LOT of work just to get satisfactory performance from that combination

[matcho mick]

thanks Lozza,got me thinking,if it's the It box reguardless of where the stator is positioned for ign timing,i'll hotwire the YZ100's box in & see what that does,(it has a circular connection block,whereas the others are just plug n play  ), btw it's only 2 ignition systems atm,i'wasn't using any YZ100 bits!,pissy little crank nose,the It J has larger taper,which bugger that ign swap,

[fred99999au]

There was a good writeup on another forum and in that case, the pulse coil was used to retard timing at a certain rev point, but the charge coil controlled the normal timing, hence high speed and low speed coils on some models.

[Lozza]

There was a good writeup on another forum and in that case, the pulse coil was used to retard timing at a certain rev point, but the charge coil controlled the normal timing, hence high speed and low speed coils on some models.

That sounds like an old wives tale. The CDI controls the timing always. One has to make the AC power the other has to tell the cdi when to fire.

[matcho mick]

ffffarrrkkkk,tried mirroring,upsidedown,reversed,cant get past too advanced,or no advance at all,(dong dong dong),just put the YZ100 igntion back on,& its too efffing advanced on the stobe,arrrggghhhh ,capitulation, going nigh nighs,

[Lozza]

Time to bite the bullet and just get the correct ignition for the bike

[matcho mick]

put the std one back on Lozza,dial guaged it again  ,few laps of VTR Putty  this weekend,like riding a chainsaw  , ,motor transplant coming up  ,