rapido 225

[Martin s]

Hi, is there a quick way of checking a rapido barrel to see if it's a race or classic? Got a kit which came with an escort 2 ring piston. Not got crank in yet. Seller couldn't tell me and I've not seen one before.

[dscscotty]

A race rapido has a higher/bigger exhaust port, if you measure the top of the port to the top of the cylinder the race will measure around 34mm the classic around 37mm

[Martin s]

Thanks Scotty, it's 34 mm so a race then. I've trawled the million rapido threads, and will be using 58x107 crank, 30mm phbh preferably with a filter, and a clubman. Wondering what anyone recommends for gearbox and sprockets, for 1 up mainly. Got GP 200, SX200 and late pacemaker gearboxes.

[dscscotty]

look to gear it at about 4.9- GP200-19x47 or pacemaker 18x48-should be ok with a clubman

[Martin s]

Cheers

[Warkton Tornado No.1]

Unless you are committed in some way to the 58 mm stroke, you should consider a longer stroke as a means of juggling port timings.

I don't use PH (or any round slide carbs designed for a four stroke), but the 30 mm VHB two stroke carb equipped Rapido 70 mm x 61 mm stroke I have easily pulls Pacemaker with 19 x 46 which is TV200 equivalent. Through an air filter & a home made 'Clubman' with a l-o-n-g reverse cone

[Meds]

I ran mine with a 28mm phbh, BGM clubman, 58x107 crank, 19x46 with an Italian GP 200 box.
Lumpy as hell low down and topped out at 70mph.
The lumpy ness wasn’t cured until I fitted a TS1 piston and an aftermarket Reed, but by that time I had a PM pipe on it.

[gerryjunior]

i run a 225 race with a 30 phbh,58 x 107 , bgm clubman and sx 200 gearing, its a really good set up and pulls cleanly from low down, tops out around 70 ,,