RM125T ignition issue

[Doc]

Have a friend with an RM125T that simply will not run unless the stator is fitted 180° out    Below is part of an email sent and like him..I simply have no answer. Hoping someone here may have had a similar issue ?

 Have an 125 T engine (rm)...was rebuilt lower end wise a few years ago...when i got things all done it was 'i think' 180° off...no kidding...so done the normal..key good...even went with a tight 25 over jug piston rings...great spark just at the wrong time...hmmm ....just for ha ha's turned the mag 180...instant first kick start and ran well...hmmm...so thinking High speed low speed coils....used two different known electrical systems ..and it will not run unless i put the mag in 180° off...just gotta tie wrap the feed wires to the lower coil so it will not rub on the rotor...runs very well almost too well...even changed the coils on the plate so to get the wires in the right place...had to turn it back the other way...tried two different rotors...all good stuff...runs great and is gonna stay this way  what did i miss

[Lozza]

What about the part with the timing marks on it is reversed? Do all the marks line up with a timing light?

[Doc]

I doubt there has been a timing light put on it Loz,

Normally it's simply a case of bolt the stator on, align the plate mark with the mounting screw centre or case mark (whichever it may be) and it's somewhere within the ballpark..enough to at least start and run.

I've had little to do with the N or T models but I can't think of anything that could cause this except maybe an incorrect rotor or stator. As he says, he's tried different 125N/T rotors and stators with the same result. This guy has been around aircooled RM's longer than me and has plenty of experience but never seen/heard of this issue before.

Trying to get some close up pics of the offending ignition but if the ignition is correct for the model then I'm at a complete loss also

[Davey Crocket]

There where a lot of unique parts for the 125T Doc....a lot of people think they are the same as the N but pretty much nothing is....make sure the engine number is correct for a T and go from there.....cranks....cases....barrel....bla, bla.

[Simo63]

If it runs with the stator 180 degrees out then is it possible the two coils are on the wrong side of the stator plate?  Or the ignition plate is fitted 180 degrees out?

[suzukimx]

The N and T are pretty much the same animal here in the USA...79 had the 428 chain and different guide  as the 80 had a 520 chain...carries the same CDI and Mag/Rotor  for both years..while the crank halfs carry a different part # as the last two numbers differ 220 vs 200...but as they use the same electrical parts...also they time well with out a light..until you get to the very fine tune...interesting...cheers   buzzymx45

[oldmxracer]

Buzzy! How you been man. Good to see you here......(Andy from southern Illinois)

[Lozza]

The light will show the firing point which is what you want to know.

[JohnnyO]

The N and T are pretty much the same animal here in the USA...79 had the 428 chain and different guide  as the 80 had a 520 chain...carries the same CDI and Mag/Rotor  for both years..while the crank halfs carry a different part # as the last two numbers differ 220 vs 200...but as they use the same electrical parts...also they time well with out a light..until you get to the very fine tune...interesting...cheers   buzzymx45

Yes I've checked through both parts books and the N and T are basically the same bikes and engines here in Oz with small changes to the crank and cylinder porting the main difference. Ignition, gearbox, clutch etc are the same.

[shelpi]

ya might have a stator out of an earlier model in there, say around the RM125B era, suzuki also changed the exit locatations on the mag cover, so look close and see if its the wrong stator or the wrong magneto cover

[suzukimx]

Andy..doing well..riding more than ever now that i live a bike friendly State..they welcome dirt bikes and ATV's here  far cry of having cops at your door step like back in CT...yea almost forgot i was a member here...getting ready to build another PERM 175..got 5 years on the first one..this time gonna use a RS 175 motor..and either another RM 125 T frame or may go with an RS frame..as i have one..another mutt..but fun...been working out very well in PV motocross...and just went to a win in a flat track deal as part of an iron man event..out of place for a PE motor...buzzymx45

[Doc]

Hey Buzz, good to see you

Thanks Simo and Shelpi, I had also thought an earlier '77/'78 ignition or rotor may have been the culprit or the hi/lo coils in the wrong place but the both the stator and rotor have been swapped for known working N/T items during the process of elimination with the same result. Not to worry, so long as it runs sweetly I guess it really isn't a big issue but the mystery remains.
 

[shelpi]

Hey Buzz, good to see you

Thanks Simo and Shelpi, I had also thought an earlier '77/'78 ignition or rotor may have been the culprit or the hi/lo coils in the wrong place but the both the stator and rotor have been swapped for known working N/T items during the process of elimination with the same result. Not to worry, so long as it runs sweetly I guess it really isn't a big issue but the mystery remains.

thats it, all good

[Simo63]

Hey Buzz, good to see you

Thanks Simo and Shelpi, I had also thought an earlier '77/'78 ignition or rotor may have been the culprit or the hi/lo coils in the wrong place but the both the stator and rotor have been swapped for known working N/T items during the process of elimination with the same result. Not to worry, so long as it runs sweetly I guess it really isn't a big issue but the mystery remains.

If you've swapped the parts for known working parts and still have the same problem and solution the maybe the keyway for the ignition rotor is on the wrong side of the crankshaft?  Do you know what I mean?  If you have another LH crank half then it should be an easy thing to check if you haven't already done so.

Would that even be possible?

[asasin]

hi DOC I had the same issue the other way around  in my 77 125 b , it turns out that there are two stators with slightly different part numbers etc they look identical but as you have said run 180 degrees out of sync. it makes no difference in running only to the position of the wiring in the mag cover.