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Is my Main Jet small?

Posted: Sun Aug 16, 2009 12:12 am
by Dimitrios_231
Scoot runs very good,
plug is on the safe dark brown colour.

I use the large breath sweet remote filter from CamLam.

Rapido Classic 225,
Ancillotti,
PHBH 30,
Champion N3C plug

main jet 120
choke 70
idle 53
slide 40
av264
x13 second clip down
airscrew 1,5 out
300 float needle valve

Tried 122 and 125 main jets, but was spluttering at half to WOT.

I read that most people are using higher than 120 main jets, at 225s with 30mm carbs.
Does 120 sound too small ?

Re: Is my Main Jet small?

Posted: Sun Aug 16, 2009 1:35 pm
by a.j
I run a 125 jet on my mildly tuned 200 with 22mm carb. Its not particularly fond of poodling along at half throttle but at least it wont fur king seize up now.

:mrgreen:

Re: Is my Main Jet small?

Posted: Sun Aug 16, 2009 10:18 pm
by drunkmunkey6969
The size of your main jet can be compared to other known setups for a rough guide, but its only too big/small in relation to how it works on your machine.

If for example you had a pal that ran a similar setup with 122, but yours coughed and spluttered....then 122 is too rich for you.

There are soooo many variables that you have to look at how a jet works on your machine, for you......full body/cut down/fat rider with Mrs and luggage/skinny solo rider/gearing/clutch/crank type/stroke/rod length/port timings/state of tune/carb/pipe.panles on/panels of/hole in panel/filter/no filter etc etc etc............

So if a 120 is right for your machine, dont worry too much about comparisons, they are just a starting point. :)