Inner rotor Kit

[Stewy138]

Purists are probably best not to read this post.

A 'mate of mine' was asking if anyone has tried fitting one of the chinese inner rotor kits to a vintage 2 stroke with any success.  I think his idea is to dramatically reduce the weight of the flywheel, either that or top replace an existing inner rotor and stator.

Thanks,

[crabman]

Hi
I am aware that one of the top VMX guys has been playing around with some Chinese electrics for use in the older bikes. I thinkn he has a Maico runner using the Chinese electrics. I will try and get you an update.
Good luck.
Crabman

 

[Nathan S]

The Chinese 4-stroke CDIs have a poor advance curve for a performance 2-stroke, but otherwise the idea is sound.

[Lozza]

Your 'friend' would be a fool for thinking light flywheels are a good idea and a genius for some lateral thinking.The external trigger ones are the ones to use. No drama's using them electronics are as good as any and if the stuff up a few$$ has a brand spanking new one.

[BETRIC]

I set up a Z50 chinese inner rotor race kit onto an a XR75 K1, I had to machine the taper out and press the steel taper from a standard rotor into the machined chinese rotor also modified the backing plate, tested it on a standard motor and it worked great, it is now mounted to my DG Monoshock XR75 motor which is very modified, I hope to have that motor running very soon, it cost me about $35 to set up.

[firko]

There's an advance curve module available to convert Chinese 4t ignitions to 2 stroke application. How much you ask?..$3.

This will start the usual burst of "Chinese shit, I wouldn't have it on my bike" retort but that's your loss. We put one of those Chinese ignitions on Franks homemade ignition dyno and the Chinese ignition matched and in some places exceeded his digital PVL up to about 10000rpm. The Chinese dropped off at 10k and the PVL carried on for another 2000RPM. We reckon with some fiddling we'll get the Chinese ignition working as well or even better. Another advantage...The Chinese ignition costs around $40 while a digital PVL costs around $800.  


Frank Stanboroughs building a remarkably trick NSU Sportmax powered Greeves pre 65 250 class bike and he's not sparing the dollars. After trying the Chinese ignition he's going to use one on the NSU motor instead of the PVL and will replace the Boyer on his Manx Metisse with one. I'm using one on my 250 Ducati and Jonesy is about to use Chinese ignitions as a part of the 'modernisation' of his Sprite Husky clone engines using the above 3 buck module. I'm thinking seriously about adapting one for the 250 Maico engine that's earmarked for the little Metisse. If it works (which I'm certain it will), it'll save me a packet by not having to buy a PVL as I have on my other Maicos.

There's big money to be saved by using Chinese bit on our vintage bikes. I got over my bias and now have Chinese wide pegs and throttles on all of my bikes and I'm gradually changing over to using pitbike chain guides. There is a bottomless pit of inexpensive parts that adapt well to out old bikes. Look outside the circle.

[Stewy138]

Geez dont you blokes work for a living 

Only joking - beats doing the books for sure.  Anyway there were a few things I didnt quite understand.  Ok I admit that I am the goose asking the question - my bike is a PE175C which has a bloody heavy flywheel intended for hill climbs and not chasing cr250'

[Stewy138]

whoops wrong key - anyway as I was saying..I havent heard of the external trigger ones lozza if you could please enlighten me - thanks.

And the advance curve module - what is that and where can it be got - havnt heard of those - its probably an extra capacitor or something I guess at that price.

I was thinking that I would keep the PE CDI and replace the flywheel and stator only.  Would need to figure out hte timing aspects as well.

I have to say that I do dislike the idea of using chinese shite on my lovely old girl, hence my caveat at the start of the topic.  But I figure that electrics are a means to an end and this is just an idea to get her running a bit snappier.

Thanks to all
Andrew

[HL500]

Hi guys, can you enlighten me on the name of the Chinese systems and maybe a link.  I'm game.

John

[firko]

Try the below eBay link John. It pays to shop around though..the prices vary a bit. Also look for a complete unit that includes the coil. The one I posted doesn't come with a coil. While you're there have a gander at the billet throttles and wide footpegs. With the wide footpegs, ignore the aluminium ones and go for the stainless steel or cast iron versions.
http://cgi.ebay.com/ebaymotors/Ignition-Magneto-Plate-50-125cc-Dirt-Pit-Bike-Honda_W0QQitemZ370230510198QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item5633754276&_trksid=p4506.c0.m245&_trkparms=65%3A12%7C39%3A1%7C72%3A1171#ebayphotohosting

[BETRIC]

What firko shows in the post above is the kit I used, I also used a coil from a 81 CR80R as you can replace the lead for longer length to the plug, I have another kit ready to go on an XR80 motor, the taper on the rotor was correct but had to modify the wooddruff key width and also the backing plate.

I brought the kits from a Evilbay suppler in Hong Kong much cheaper than the States.

[Viper79]

How do you set up the timing on these kits, surely the location of the key way and backing plate mounts wont suite every application?   

[firko]

I brought the kits from a Evilbay suppler in Hong Kong much cheaper than the States. 

Absolutely Dave, US price $75 plus shipping, Hong Kong price $39 with free shipping. It's a no brainer.

[Nathan S]

V79, The location of the keyway is irrelevant - the key only exists to make installation easier.

Backing plate mounts are expected to be changed - but as Firko's pic shows, the design lends itself to being modified without too much drama.

Other issues are the angle and diameter of the taper (particularly the diameter, as there's only a very narrow range of taper angles that are self-locking), and the overall height.
Most VMXers have the skills/contacts to deal with these dramas...

[firko]

Here's a shot of the Chinese inner rotor ignition mounted on Betrics trick DG framed XR75.