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The 2-Stroke Garage => Turning Wrenches => Topic started by: rd400canuck on August 03, 2020, 04:32:43 PM

Title: leaner needle?
Post by: rd400canuck on August 03, 2020, 04:32:43 PM
Hey guys... has anyone run the stick needle on the 2nd clip to lean it out one notch on a stock set up?

I have all stock except the oiled air filter and i run a 25.7 pilot (stock was 50) and a 140 main. I run the air screw at 1/4 out otherwise it bucks like mad when i close the throttle. I think my current setup causes the 1/8 to 1/4 throttle to be too rich and i get that burbly spot between 4 and 5000 rpm on the hwy and bombing around town.

Is leaning the needle something one can do to clean up that area of the rpm at steady throttle?
Title: Re: leaner needle?
Post by: SUPERTUNE on August 03, 2020, 10:03:24 PM
Quote from: rd400canuck on August 03, 2020, 04:32:43 PM
Hey guys... has anyone run the stick needle on the 2nd clip to lean it out one notch on a stock set up?

I have all stock except the oiled air filter and i run a 25.7 pilot (stock was 50) and a 140 main. I run the air screw at 1/4 out otherwise it bucks like mad when i close the throttle. I think my current setup causes the 1/8 to 1/4 throttle to be too rich and i get that burbly spot between 4 and 5000 rpm on the hwy and bombing around town.

Is leaning the needle something one can do to clean up that area of the rpm at steady throttle?
A #25 pilot was stock on all RD400's not a 50...

I always tried to help this issue and found that when I did drill out the ball and re-drilled and tapped for a removable air jet I used a .7mm air jet and not the stock .5mm air jet and did help much better with the clip on the #3 position using 30 pilots.
(pre-mix 40:1, stock air box with Uni filter, drilled stock baffles in stock pipes)

Use a 5 X.8 tap and re-plug with a set screw where I drilled out the ball. (caution: tap only 2-1/2 threads so the set screw is not too deep!)
I did have this posted on the old forum, unfortunately is now lost in space...
Chuck
Title: Re: leaner needle?
Post by: rd400canuck on August 04, 2020, 02:42:37 PM
Yes 25 pilot! Not sure why i wrote 50 there lol..

Ive got the drilled and tapped set up and i think i have some .7s somehwere. Im gonna have to try it.

Im just afraid to lean the needle from stock considering the bikes want richer with the gas these days. The stock 25 pilot was too lean when i tried it.

Ok.. ill try that set up this weekend and report back.  Ty