Rapido 200 fettling

[DRC86]

In my workshop ive got a near new rapido 200,a nice 67mm asso thin ring piston and a suitable head.had a quick chat with ian frankland over the weekend.he suggests taking a bit off the base of barrel to make it work better.was going to get it bored out to 67mm.and then do this.using 30 delly and jl3.anyone got a similar set up and who to use for barrel mods etc.how much?.

[tha83]

In my workshop ive got a near new rapido 200,a nice 67mm asso thin ring piston and a suitable head.had a quick chat with ian frankland over the weekend.he suggests taking a bit off the base of barrel to make it work better.was going to get it bored out to 67mm.and then do this.using 30 delly and jl3.anyone got a similar set up and who to use for barrel mods etc.how much?.

Is this a race Rapido or classic? I hadn't heard of taking it off the base. You want to raise the ports, wouldn't you use a packer and skim the top? I have a Race 218 at this point. Just did a new MB piston and an LTH reed. Before my set up was piston ported, I've changed the port timing slightly and now it acts a little more like the race 200 but without loss of the low end as much. It's a bit rough at the bottom end and goes like hell when it starts to hit the power band. I love my taff pipe but it's holding it back quite a bit. MY gearing is a tad high and the 5 plate clutch slips quite a bit. I have to go with the Barnett springs and 150 gears again. If you've spoken with Ian Frankland then I'd suggest following his recommendations. I've got over 7K on my kit and the lad that tuned it was a great admirer of Terry Frankland's, Terry had given him quite a bit of advice over the years. Again, I'm suprised to hear about taking it off the bottom. People trim piston skirts, use packing plates and skim the top of cylinders IIRC. Is it possible you mis heard? I'd be interested to know since I only know enough to usually get myself in trouble. Good luck.

[goldeneye]

is it a "race" barrel? he might have suggested tailing the barrel to calm the timings, but fitting a full skirt piston would have the same result. a couple of local lads are running 200 rapidos, both clubmans and 28mm carbs (a kiehin and a delly) both go well. the exhaust port on the race compared to the classic is huge. my classic 225 is great , cant fault it. the GP i"m building , i got a race 225 cheap, with carb pipe etc, and thats what im putting on. i"m a big fan of Rapidos. "it"s no TS1" aye, but its no 500 pund either....

[Muppet]

couldn't you achieve the same by fitting a long rod like a 110 then use a 2mm under the pot leaving the piston 1mm higher at all positions; then use a recessed head to give the piston clearance at top of the pot; you still have a full length pot an if it don't work as you wanted you can go back to the standard timings,

muppet

[DRC86]

Im not sure if it is race or classic to be honest.i ought to know.....but i dont!!.ian was talking about taming it a bit.i may have misheard him.to be honest i will probably just bore it to suit the piston and see what its like.still trying to set up my taff 205....which is what started the conversation anyway.i was enquiring if its worth using a hon 205 piston in a rapido.his answer was basically whats the point!.thanks for your input peeps.

[shadyady]

I run a Rapido Race bored to 205 cc, AF RB crank, MBDfull skirt race tour piston, 30mm spaco carb, compression ratio 10.5:1, barrel shortened from the top(to get a decent squish), reprofiled head, JL3, SX200 gear box, 46 rear & 14tooth front sprocket, 5 plate cluch. It carrys my 17 stone lump up hill and down dale, and goes like stink