need a starting point on jetting

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r1yfz
Posts: 211
Joined: October 7th, 2009, 6:03 pm

need a starting point on jetting

Post by r1yfz »

1200ft
cpi exhaust
porting
cr250 ignition
boyseen reed cage
42mm sudco


300ft racing

id rather be rich than lean!
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2strokeforever
Posts: 1524
Joined: November 13th, 2009, 1:04 pm
Location: Vernon B.C Canada

Post by 2strokeforever »

42mm sudco
mikuni or kehin?
the 450 will have less power and will be harder to start, and will be heavier, but to make up for it it will require more maintenance.
4stroke=dead fish
r1yfz
Posts: 211
Joined: October 7th, 2009, 6:03 pm

Post by r1yfz »

kehin
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Nodge
Posts: 527
Joined: October 31st, 2007, 6:12 pm
Location: Saskatchatoon

Post by Nodge »

I'd say start with a 180 main.
But what do I know....... :wink:
Yah, I'm from Saskatchetoon!

MRE 02 250/500 conversion, pulse injector, twirp porting, coolhead, MRE ignition, blah blah blah blah... www.millarengines.com
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kdizzle
Posts: 372
Joined: May 7th, 2008, 10:03 am
Location: Phoenix, AZ

Post by kdizzle »

I am close to your setup but with a PC pipe.

41.5 PWK carb
#7 slide
60 Pilot
185 Main
DGK Needle

1/2 turn out on the A/S on my bike with this setting.

Remember, If that stator isnt clocked right it will be hard to jet, what the right amount is? well that is the million dollar question!

Do lots of testing and if you cant get the ping out before it blubbers you are too far advanced. Clock the stator plate a bit Counter Clockwise to retard it a bit, and test again.

It took me a weekend or two of fiddling but i eventually got it right. Remember if you shaved the head or added compression that can play a factor in the ping as well.
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