Page 1 of 1
ideal carb size for a stage4 GP and RS pipe
Posted: Sun Aug 30, 2015 4:03 pm
by Davidsquaredson
Hey,
a friend has a stock GP engine and carb, but added a scootrs expansion chamber exhaust. He wants more performance primarily for in town use and period light touring (max 100 kmph) . So low to mid range torque. I think a clubman would be a better pipe but he's already bought the scootrs exhaust.
I've got a stage 4 tuned jet200 barrel I'm not using so was going to offer to him. What size Dellorto carb would ideally pair with this. Assume using a bellows and remote foam filter.
tx in advance
David
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Sun Aug 30, 2015 4:06 pm
by Norrie Bodge
26mm delly would be ideal IMO
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Wed Sep 02, 2015 5:45 pm
by Davidsquaredson
thanks!
I have a 28mm in my set up and I thought it was too much carb for this . Was thinking it would be 24 or 26, was waiting to see what someone with experience would say.
Cheers
David
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Thu Sep 03, 2015 10:03 am
by shocky
Why not a 22mm im hitting 100kpm with my stg4 and clubman it pretty much flat lines after that though as I was expecting a genuine 70 mph

Re: ideal carb size for a stage4 GP and RS pipe
Posted: Thu Sep 03, 2015 1:54 pm
by shaunmc
I'm using a 26mm delly on Stage 4 with a scorpion exhaust no filter changed from 30mm. Really happy how it performs.
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Fri Sep 04, 2015 8:20 pm
by corrado
Davidsquaredson wrote:primarily for in town use and period light touring (max 100 kmph) . So low to mid range torque. I think a clubman would be a better pipe but he's already bought the scootrs exhaust.
I think you're right too.
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Fri Sep 04, 2015 8:56 pm
by Strummer10
Must admit my GP 200 stage 4 with a 22mm standard carb and scoots rs expansion flies and is as quick off the mark as mate's TS1 and gives it a run for it's money.......but I have decided to put a 30mm delorto on it with breathe easy and see how it goes after
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Fri Sep 04, 2015 10:31 pm
by vespanic
You might find his Indian barrel is stage 4 tuned. Most of the barrels in the last few years have been stage 4 tuned as a standard.
Re: ideal carb size for a stage4 GP and RS pipe
Posted: Sun Sep 06, 2015 8:18 am
by gaz_powell
The standard Indian SIL barrels are very loosely stage 4 - they are not like a hand attended to stage 4 where ports are cleaned/polished/edges along with manifold matching.
There is a bit of a difference.
Back to the original plot I like the 26mm not long changed a 30 for one for a mate and it's much better. On a factory 200 SIL barrel with a bit of tidying up and manifold matching..