MB100 development

[husaberg]

I dont know what the rattle was, I would have to hear it to know more.

Yes the flywheel could just creep gradually, moving a bit with each miss change. Others have made lots of good suggestions about how to fix the damage and get the tapers to fit properly again.

The taper on my Suzuki GP125 is much smaller than the MB so the KX80 ignition is out but the KX125 might be worth a look as it has a bigger diameter taper.

Speedpro recently converted his, it would be worth looking at his #6 thread to find out what the doner engine was.

He has a MB5 one and a MB100 one spare. Plus a CR80 rotor and Stator minus the CDI unit.
I will paste him the model to look for on Ebay. I do think one step at a time with this motor he also mentioned to me it was spitting back.

[Grumph]

I would also suggest to let someone have a look in the motor before slinging it back together Yowl ling or grumph would be a good start.

Kind thought...but Grump is broken at present....post Greymouth.
I'm getting too old for this shit - and it was in the pits to boot.

[husaberg]

Kind thought...but Grump is broken at present....post Greymouth.
I'm getting too old for this shit - and it was in the pits to boot.

You should have brought sunscreen catches you CHCH people out all the time

[Hilleye]

I would also suggest to let someone have a look in the motor before slinging it back together Yowl ling or grumph would be a good start.

Yow Ling has already kindly volunteered to assist in the reassembly.

[Hilleye]

Alright so here is a picture of the existing flywheel. From what I can tell there is a superfluous plate (marked with arrow) on the outside of the main assembly that just adds weight and hence rotational inertia (not good considering what we are after) and is probably contributing to the sheered flywheel key phenomenon. Can I ditch this plate by grinding off the four marked pins/rivets without messing up the ignition?



Here's a comparison between the old and a new flywheel key. Be fair to say the old one is 'munted'.

[F5 Dave]

Oh gosh no, that's the transmorgifier. It won't run without that.


yeah those rivets just blaze off & free frizbie.

Smaller flywheel would be better still. old aircooled CR80 stator assembly bolts right on, but with an adaptor plate & a new taper cut any other mx80 will fit. just doing an RM80 one presently.

[speedpro]

Can I ditch this plate by grinding off the four marked pins/rivets without messing up the ignition?

Don't do it. The extra plate does add mass but it also helps rigidity. I did it on the sidecar MB engine. Some time later the rivets connecting the rotor to the centre hub rattled loose. They shagged out all the rivet holes and if I recall there were a couple of cracks. Luckily it broke a wire and killed the engine before the rotor came right off. If crank inertia is a problem you are probably at the point where you need a better ignition anyway. Save your pennies and get a CRF250F generator/stator and use that to power and trigger an Ignitech. The CRF rotor bolts straight onto the MB crank like it was made for it and the mounting plate for the stator can be made from a piece of standard 14mm plate.

[Hilleye]

MB5 gearbox Pics of Layout that wouldn't fit above

Plus those Mad Swedes are at it again MB5 crankcase reed.
I not sure if he started before Dave or not.

http://forum.scooterforum.net/forum/...roject-153286/

Any chance you could post a better quality picture of the 6 speed transmission diagram or send a link to it?

[husaberg]

Any chance you could post a better quality picture of the 6 speed transmission diagram or send a link to it?

I will send it too you it should have gone with the bits anyway. I can try and post it on the MB thread I will have another go with the quality have you zeroed in on it with the plus button?

[Grumph]

I'm advised that a long time accumulator of MB bits is thinning the piles....Hilleye has already been offered bits and Dave will be (w)rung too.

The balance is to go on trademe.....so keep an eye out if you want engine parts.

[speedpro]

Not sure why you want a diagram of a 6-speed cluster for. To fit the 6-speed into a MB100 you get the whole 6-speed cluster and fit it. No mods or alterations are needed it goes straight in and makes the MB100 one of the better bucket engines - good cylinder, vey good crankshaft, and excellent gearbox.

[koba]

I'm advised that a long time accumulator of MB bits is thinning the piles....Hilleye has already been offered bits and Dave will be (w)rung too.

The balance is to go on trademe.....so keep an eye out if you want engine parts.

Ow!
My eye is out.

[F5 Dave]

Don't do it. The extra plate does add mass but it also helps rigidity. I did it on the sidecar MB engine. Some time later the rivets connecting the rotor to the centre hub rattled loose. They shagged out all the rivet holes and if I recall there were a couple of cracks. ., .

You must have got a bit unlucky there combined with the fact the sidecar did a million revs. The MB50 for example has a very similar flywheel & never came with that plate. I think your rivets must have just got shagged out on thier own accord given the situation they were in & the high loads placed on them with a sidecar wheel jumping all over the place & probably little in the way of cushioning.

[husaberg]

You must have got a bit unlucky there combined with the fact the sidecar did a million revs. The MB50 for example has a very similar flywheel & never came with that plate. I think your rivets must have just got shagged out on thier own accord given the situation they were in & the high loads placed on them with a sidecar wheel jumping all over the place & probably little in the way of cushioning.

When I ran The H100 original we removed a ring like that.
I am not sure if it was the H100 points one or an original MB5 one, as I had ran both.
The flywheel was lighted at the same time by a lot.
Well it was to much and it broke along the front face outside the rivets.But not because the ring was removed. I can't remember where it hapened.
On the H100 motor Hilley has it has been lightened by a lesser amount. I don't think it had the ring on it.
But you live and learn. To be honest lightening the flywheel makes it rev faster at a standstill but doesn't seem to make much difference when racing.
Hilley has a CR80 AC one that will just purchase a CDI unit from Ebay

[F5 Dave]

I had a heap of MB50s over the years & none ever had the ring so must be a 100 thing. My mb50 I ran a CR80 stator & a YZ80 CDI so don't get too bogged down with compatibility. white\orange was pulsar coil & that was all you needed to know.