RB20 (200cc) - Pictures and Spec

[shocky]

yea more money

[ArKaTxU]

yea more money

[J1MS]

News about the kit?
In LTH Germany there are RB20 kits with diferent pistons.
With Vertex Pro and Wiseco pistons.
You know the diferences using this pistons?

When I spoke to Ben a couple of weeks ago, he said they were using the Yamaha Blaster wiseco piston, but would be using a Vertex piston in the later RB20's, with a different boost port window which should be better, if I remember correctly. But I was very Impressed with the overall build quality of the kit.

[drunkmunkey6969]

Engine build is underway.....i've cleaned up the casings (cleaned not blasted) fitted hi-load bearings and seals, fitted n shimmed the gearbox, layshaft, selector etc, drilled out the clutch basket to lighten it, dremmeled down the lip to accommodate 5 plates and had the spider welded. Sean has ported casings n crank beatifully (see crank post), and i've now slotted the crank in, fitted the mag-flange, got everyting torqued down, and am sorting out the gearing/chain/clutch etc next. Then i can slot on the top end and check the port timings so Sean can then port the cylinder.....so we're a couple of weekends off being ready yet, but its taking shape. Road/race frame should be delivered end of this week....

[sean brady scooters]

just done the manifold...........
on the left is a std one for comparison.......the center rib has been" knife edged "internally also
inlet as std is 33mm bore........opened out to 35mm to suit TMX............

[sydduckett]

drunken, is the crank you have there the one that AF reccomend in there ad "RB20 Race Crank 116mm rod" for the RB20 kit they have on there site?

cheers
sef

[drunkmunkey6969]

drunken, is the crank you have there the one that AF reccomend in there ad "RB20 Race Crank 116mm rod" for the RB20 kit they have on there site?

cheers
sef

It was when we started.......but as you can see...its been modified by Sean.

[sean brady scooters]

just for interest........some other crank webs used for various things


What you see here are the crankshaft assemblies for small engines used on brush cutters, chainsaws, and, in particular, motorcycles. We also produce single-unit crankshafts used for outboard motors, compressors, and other such items.From 20cc brush cutters to chainsaws, motorcycles, outboard motors, and even 700cc snowmobiles, we produce the crankshaft assemblies.

No. Applications
1 Water vehicles
2 Motorcycles
3 Chainsaws
4 Brush cutters
5 Small-scale helicopters
6 Outboard motors
7 Compressors
8 Chainsaws
9 Motorcycles
10 Snowmobiles
11 4-wheel all-terrain vehicles
12 Snowmobiles
13 Blowers
14 Chainsaws

[Stokie]

Just a question
Why have you decided to tune the barrel prior to running it - even on a dyno ?
The suggestions are that they're a powerful kit out of the box so for comparison I'd have thought it worthwhile doing a before & after dyno run.

[drunkmunkey6969]

Just a question
Why have you decided to tune the barrel prior to running it - even on a dyno ?
The suggestions are that they're a powerful kit out of the box so for comparison I'd have thought it worthwhile doing a before & after dyno run.

They are powerful......very good kits, great design........but the exhaust port is ripe for a tune.

And dont forget, they are mass produced for road use etc, taking into account the 'safety factor' tolerances for poor maintenance etc.....they can be pushed further with no problem.

The comparisons would be great......but so much more work.....build a completely standard engine, run it it, dyno it....and then have to strip it all and down, tune it...casings, crank, cylinder etc....what a ball ache. We know what we want to end up with, and how to achieve it......so why not just do it right first time?