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Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Thu Aug 12, 2010 12:34 am
by adriang
I whacked a mikuni TM24 on my GP200, replacing the standard delly. Really pleased with it, it seems to be snappier with the response, and is certainly a bit more economic.
Just thinking over the balance between performance and economy, and was thinking about downsizing the carb on my Rapido 225 from a 30mm PHBH to a Mikuni TM24. Anybody tried this, got any thoughts???
Not to worried about performance, I'm collecting parts for an RB based DTC knock-off.
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Mon Aug 16, 2010 1:00 pm
by Train Driver
24mm mikuni and ancillotti exhaust, this is my jetting which after 2500 miles is still spot on.
Jb dyno'd
main jet 175
pilot 20
needle 5n1b
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Thu Aug 19, 2010 2:50 am
by adriang
Train Driver wrote:24mm mikuni and ancillotti exhaust, this is my jetting which after 2500 miles is still spot on.
Jb dyno'd
main jet 175
pilot 20
needle 5n1b
thanks..
more questions!
Was this with an air filter?
what were the figures from the dyno?
And are you pleased with it?
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Fri Aug 20, 2010 9:19 am
by Train Driver
Air filter yes/ foam type
Dyno 16bhp 13ft/lb torque all below 6500rpm
Please yes but now running a RT255,the rapido now belongs to cezeta
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Mon Aug 23, 2010 1:30 pm
by corrado
Train Driver wrote:24mm mikuni and ancillotti exhaust, this is my jetting which after 2500 miles is still spot on.
Jb dyno'd
main jet 175
pilot 20
needle 5n1b
Is that the carb that I now own Paul? The needle sounds wrong though, I'm thinking it's 5N13. I upped the main jet to 195 while running in my Mugello 225. Bottom end seemed very boggy so went down to 17.5 pilot which is still boggy but not getting much time to dial it in at the minute. I'll cope with the rich bottom end but need to do some top end plug checks before riding to IoW on Thursday. I'm using a Breath Swet filter and so far not run it with the panels on. Had plans to try today but it's persisting down oop norf.
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Mon Aug 23, 2010 5:11 pm
by cezeta
having gone from a 35mm mikuni to a 30mm and got better performance im sceptical of the big carb desire. a well known tuner has insisted he can get similar power from a ts1 from a tm24 and encouraged me to be the guinea pig so there is food for thought there
its not just size but volocity aparently
(now wait for the usual culprits to quote something out of a 1970s book :baddevil: )
martin, it is an sn13......was written funny by john at jb as i recall
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Tue Aug 24, 2010 5:07 pm
by Train Driver
corrado wrote:Train Driver wrote:24mm mikuni and ancillotti exhaust, this is my jetting which after 2500 miles is still spot on.
Jb dyno'd
main jet 175
pilot 20
needle 5n1b
Is that the carb that I now own Paul? The needle sounds wrong though, I'm thinking it's 5N13. I upped the main jet to 195 while running in my Mugello 225. Bottom end seemed very boggy so went down to 17.5 pilot which is still boggy but not getting much time to dial it in at the minute. I'll cope with the rich bottom end but need to do some top end plug checks before riding to IoW on Thursday. I'm using a Breath Sweet filter and so far not run it with the panels on. Had plans to try today but it's persisting down oop norf.
sorry martin i typed it wrong it was 5N13,
the rest i cant help you with it was set up on the dyno at Jb's, with a K&N style filter
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Wed Oct 13, 2010 5:07 pm
by mickdale
cezeta wrote:having gone from a 35mm mikuni to a 30mm and got better performance im sceptical of the big carb desire. a well known tuner has insisted he can get similar power from a ts1 from a tm24 and encouraged me to be the guinea pig so there is food for thought there
its not just size but volocity aparently
(now wait for the usual culprits to quote something out of a 1970s book :baddevil: )
martin, it is an sn13......was written funny by john at jb as i recall
hello cezeta - mate in my club is running a tm24 on his ts1 and really rates it.
was wondering about putting my tm24 on my torque tuned ts1 230 but not sure if it will flow enough fuel?
did you get round to trying one on yours?
cheers
mick
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Sat Oct 16, 2010 10:10 pm
by cezeta
mickdale wrote:cezeta wrote:having gone from a 35mm mikuni to a 30mm and got better performance im sceptical of the big carb desire. a well known tuner has insisted he can get similar power from a ts1 from a tm24 and encouraged me to be the guinea pig so there is food for thought there
its not just size but volocity aparently
(now wait for the usual culprits to quote something out of a 1970s book :baddevil: )
martin, it is an sn13......was written funny by john at jb as i recall
hello cezeta - mate in my club is running a tm24 on his ts1 and really rates it.
was wondering about putting my tm24 on my torque tuned ts1 230 but not sure if it will flow enough fuel?
did you get round to trying one on yours?
cheers
mick
no mick......i rode it into a concrete dranage ditch at speed in france instead
so my experiments are hindered for a while, i may have a series 1 cut down as a result soon though
using a 30mm kehin in europe this year was an improvement on the bigger carb though thats for sure.
im interested to know what manifold he uses?
Re: Downsizing carb on a Rapido 225. Mikuni TM24 anybody?
Posted: Sun Oct 17, 2010 8:26 am
by mickdale
would be interested to know the manifold aswell - i'm using a LTH inlet manifold with the bolt on rubber - wonder if i can get one to fit the carb with the right hole spacing??