Scooterotica

Am currently running a fairly stock s3 TV175 but have aquired a 200 block with the intention of building a smooth, bulletproof, economical mile muncher. I am considering using a rapido 225 barrel with a 116mm rod and piston, is anyone running this setup and are there any technical problems running this set up in a barrel designed to work with 107mm con rods regarding the ports

I've got a few spare Indian 200 barrels so was looking at doing a similar conversion using the RB20 piston and 58 x 116 rod along with a scootrs reed valve. I hadn't envisaged any extra problems over what the long rod / piston already provide.

i am also considering this setup.. I have a rapido classic barrel already which should allow the porting to remain 'sensible' with the longer stroke/rod.. i am just debating over pistons and what are available in a lower compression height..
im thinking kawasaki h2 (71mm) or equivalent wiseco/wossner
devtour
mugello

also wondering whether to go reed valve or not..

so I am too interested in any experiences or thoughts or suggested parts..

If you go reed inlet you can go with the RB20 piston, as Corrado suggests. The RB20 piston is actually a Yamaha Blaster piston so oversized versions are available up from the stock 66mm.
SF

cool.. just looked, the standard 'blaster' is 66mm upwards, but theres an 'airsal' big bore kit with a 71mm piston for a 225 barrel, maybe that will work..

my rapido barrelled sprinter uses the af rb crank with 116 rod but im using bultaco comp piston with barrel base machined to get the timings requirred. if you want have a word with Ben@af he has a few different options available.

Just about to pick up my newly built engine, top end spec-
Indian crank webs
116mm Yamaha conrod
Race spec Yamaha big end bearing
18mm small end
Yamaha DT 250 piston
AF re-profiled Head (yam spec)
Rapido Boost ported cylinder
Reed-valve
Also got 5 plate clutch set up, BGM full DC wassel conversion and Jockey rear brake
Looking forward to getting it up and running.

Do you know what conrod was used, I thought Yams were all 16mm small ends?

wack 63 wrote:Do you know what conrod was used, I thought Yams were all 16mm small ends?

Sorry Wack I don't, just quoting what I've been told