Yokomo MR-4BC/B-Max 4 spur modification.

[Dingbat]

Lately I have been having problems sourcing spares for the old yoko MR-4 BC,
namely spur gears to fit the slipper clutch.
Anyhow one day I bought a B-max 4 spur gear just to see the difference.

It turned out the spur is near identical bar the hole size through the center.
The B-max has a larger hole through it. 13MM diameter to be exact.
Whereas the MR-4BC spur fits on the 10mm diameter slipper shaft.

B-max parts are readily available,so I decided to make a simple adapter.
See pic's.

No1,after turning some alluminium stock down to 13MM diameter,
and drilling a 10MM diameter hole through I set up the dremmel to
cut off the adapter ring.
(My little lathe Is not very good and parting off is a definite no/no
hence dremmeling)







No2 The modified B-max spur.




No3 Installed spur and slipper pads.







No4 Ready for installation.







Hopefully someone somewhere will find this of some use.
Db.

[fastinfastout]

wouldn't it be easier to get a cat sx spur which is 8mm, and just drill it out to 10mm.

[Dingbat]

It would be If the slipper pads were the same.

[fastinfastout]

not the same?

I was pretty sure I have used AE slipper pads in both bmax and cat spurs before

[Dingbat]

Originally Posted by fastinfastout

not the same?

I was pretty sure I have used AE slipper pads in both bmax and cat spurs before

Fair one,
unfortunately for me I didn't have access to any other slipper pads or spur gears to try.

[Bikerbob]

Do you fellows know anyone with an extra slipper unit??

I need one for my BC.. we are running on industrial carpet and I need the slipper to save the drive train.

I am in S. Ontario Canada.. Yokomo does not exist here.

Any ideas for me with this buggy?

thanks

james

[91notch5.0]

bikerbob....i feel your pain. i ran a yr4-m2usa when sedan racing was at its best. loved the car but will never own another yok. i worked at a hobbyshop and parts were a pain. customer service was terrible too. since then, ae and losi only for me.

[Bikerbob]

Crazy eh?

Largest RC market in the World? and Yokomo USA is shut down.. almost a year ago now.

I have to say I wonder why Horizon or Great Planes have not tried to pick it up.

Maybe Yokomo themselves are not a big player anymore and dont wish to fight it out in the NA market?

On the otherhand - small players like Caster and Durango and going gang busters over here.

James