MB RB230 one off cylinder x

I've been tuning and playing with Lambrettas for many years, in that time you can not help but meet people. I couldn't count how many customers I've had. Some have never gone away and some have come and gone and some have returned many years later.

This cylinder is for a local who one day popped into the shop to start buying parts. He's a bit older than me and he'd just got into Scooters along with loads more who had joined local clubs, but most were short lived and were in and out in a couple of years. Some of these lads were lets saw 'lovable rogues' with plenty of history and well known in the area. I thought this customer would be the same in, out and gone. It was a shame as it was a time when people had money and it was money no object!

Before I did this RB this customer had already had a TS1230 off me, which was by all accounts very fast and was clocked at 100mph with his wife on! He didn't have a bad word for it and no one could catch him. The funny thing was 'it was never fast enough for him' even when he did the quick bike test on a 500 bike, that was never fast enough! He was always in, I want it faster, I want it faster! Then out of the blue he sold it! With different jobs coming and going he would pop in now and then and do another Scooter. 

One day he popped 'I want one of these new RB motors'! 'Why' I asked, 'they're supposed to be good'! So I then educated him that after lots of testing and comparing the RB to a TS1 that I still preferred the TS1 for special engines! I could tell by his face he wasn't impressed. With him been one of those what I thought was in it for the moment then off, I thought he would go to whoever was the IN dealer tuner at the time. A week later he went and bought an RB kit and brought it in! Umm I thought, 'right I want it fast'! he said, 'I want it fully welded to look like a motocross motor'! As much as said don't do it he was insistent!

Obviously an engine like this is not cheap, as with his last TS1 he did it in sections, welding tuning, crank in, cylinder done and set up, then the gearbox, then the clutch and finished off. It costs more this way but spreads the cost over a few months.

So, adamant this was what he wanted I cracked on with it. At the same time another local wanted a TS1 doing, again another 230 but I talked him into NO welding. It just so happened both were finished within a week and both were dynoed within days.

So what happened and how did they compare? This RB as all the photos showed was fully welded, with iron liner with Road Race tuning using our MB crank, all the usual, electronic, built with the best bits and it cost a fortune! In comparison the TS1 was the same but unwelded with no liner, they both used the same exhaust JL4 and the same carb.

Well both did 32bhp!

This one cost £2K more over the TS1 and unfortunately the RB had 3 small dips in the graph up to peak, where as the TS1 didn't...... for me I was right, 'I told you to use a TS1' I said in a piss taking way! But the customer was happy with the motor and still is, it's still running no one gets near him so for him it's money well spent! As for the TS1 motor it was so fast he flipped it within the week and wrote his bike off when I asked why? He said 'its just so fast I couldn't stop it' Now I've ridden Enduro's with this customer at the IOM for a week, he's had every type of bike and I know he's a really good rider. This is the difference between an engine with a totally smooth dyno graph from 3000rpm to 10'000rpm they pull like a train. Engines with dips where the tuning, porting and exhausts don't run smooth get flat spots and just don't go as good. For me I would rather loose peak power and bragging rights to a motor that pulls strong from nothing.

Like I say the RB is still running, the same customer never disappeared he's still into Scooters, he's in a local club who all keep popping in for more tuning to keep up with it. He's gone through some really heart felt problems with his wife, he's had to give up his jobs to look after her. She used to go on rallies with him, she can't even sit on a bike anymore, but he's still kept the Scooters. When we were moving he begged me to do another super engine, I just didn't have time so went elsewhere, were it cost more money took longer and only managed 200 miles when he came in for a piston and wasn't impressed with the work he'd paid for!

I've done another motor for him as a spare and I think he's talking about another. 10 years later he's still around, he pops in most days for a screw or washer but he's spent good money on Scooters we could do with a few more of him these days.

And he still says 'it could be faster' Some customers are just never happy!

And I've found so many times welded engines are just not as fast as the simpler non welded casings, unless I'm allowed to do it the MB way!


Some early RB's had to be sleeved as the machining broke through


I got rid of the sleeve and welded it up


Then the base was welded to make the Motocross transfers


I'm self taught at alloy welding


He wanted a inlet feed into transfers developed by my Iron Liner man, DJ started using it and everyone wanted one, do they go any faster?


Both transfers are welded on each side


I clean all my welding so the cylinders look standard, it's just something I'm anal at


All porting is flowed and matched


The cylinder looks standard but take hours of work, so you don't know why these things cost so much


Nothing like a well designed job


All matching with a bit of muck you wouldn't know


All my work is cleaned and tidy up


RB break reed petals, so I open out this area to stop the tips touching


It's only a small area but important


Lightly ground away


Inlet flowed and cleaned up


Casing are a work of art, these were standard Indian SIL casings


MB 60mm crank


Cylinder MRB1601 I've done over a hundred more since this


Iron linered after I welded up the auxiliary exhaust ports


I do a few of these jobs to repair damaged bores


Cleaned tidied and flowed


After the liner is fitted I re flow all the the joints


A finished cylinder, Road tuned, very reliable and 32bhp


Inlet flowed after welding


Used a MB Race-Tour piston


A flowed RB inlet manifold


Ring pegs are supported


Ready to go


Spigot to the top of the cylinder to locate the head


Ive done more than 300 linered cylinders over my time

Mark Broadhurst 2.9.2012 mark@mbseriousoutdoors.co.uk