AHA! thats very useful. i will look into

Hey Mark. thanks again for all your time and help. I have made an enquiry to HPI - their system look like a good option although looking at the diagram of the rota in the kit www.hpi.be/item.php?item=068R078 the flywheel nut would need a little shaving off it? And while looking at removing the rotor, it appears the currenr hitachi requires a 19mm puller. Do you happen to know if its RH or LH my instinct says LH???

I think they are RH on the inner rotor pullers.  Mako posted an Amazon ad to the MX puller on some pages here. 

Oh on the nut, I'm not sure exactly what you're talking about?  If the Hitachi has a special nut that would need to be modified just get one for an Enduro or from a good hardware store.  I think thread is 12mm x 1.25?

I just saw the link to the pullers on the donations page. With Firefox it's on the right margin as you scroll down.. On phones and other browsers it could be at bottom or something. 

yamaha-enduros.com/index.php/community/d...ite-maintenance-fund

Cheers Mark. I think I've sourced a UK supplier for the puller now.
Re the nut, the existing one has a shoulder corresponding to a recess in the hitachi flywheel. The dimensions are just a couple of mm broader diameter to fit into the HPI flywheel. Solutions are I guess to machine or replace with a non-shouldered item

I always suspect source coils when there's a problem. Heat & vibration & they're right in the firing line. Same with the pulser. What i've done long ago was connect an ohm meter to the coils & the pulser individually then apply heat to whichever one you're testing & assuming it has a reading because it runs--then plays up--watch the meter [analogue meter] & if faulty it'll go open circuit or start faltering. In saying that i've not had to do that for about 40 years, but just another one of those 'things' you never forget.

I agree, it seems to be pointing that way - its heat related definitaly.

I have been thinking it could be the right time to ditch the lil internal flywheel and upgrade to a modern system with heavier mass.
I'm looking into how straightforward it is to remove the hitachi stator and rotor and replace with items from a Mitsubishi sort of system - I am hoping the crank and cases will accept them OK

Full flywheel will make it nice to ride but might have clearance issues if the flywheel is as big as an RT1-2 or 3. By memory the cover is shaped a bit so as not to waste space & add weight so stepped it in a bit. If that's the case just get a mag cover from an RT-DT 1-2-3.

I might be lucky as mine has a non MX mag cover already.
I've found a system in europe which is quite well thought of in my club, Vape (bad name) 
They offer both an AC and DC system. If I'm not fussed with lights - do you think it makes any difference (as the kit includes everything from stator to coil