With the snow gone, and a race coming up the family, and I have been knocking the rust off. The other day I figured swapping the stock needle for the one (oem# n2ej) from when the bike was a 125 was a good idea...Ran pretty good other than a burble mid throttle. I had just read slicknick talking about running on the 2nd clip on his setup, so I tried it. Was on the 3rd. Burble was still there, but better. Today, I figured I'd pull the carb, and at least drop the float to 18mm from 16. Ended up doing that, pulling the jet block/gasket sinching the seal, upping the pilot, and lowering the main.
Runs pretty good now.
200cc boysen reeds, woods pipe w/kx250 Jones muffler, kdx uni in kx airbox, 93oct 50:1 amsoil dominator.
At about 3500ft and about 60 degrees.
Stock kdx carb
Pilot: 40
Main: 150
Needle: oem# n2ej (stock 97 kx125) 2nd clip
Float: 18mm
Test/tune
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Chopperpilot
- Supporting Member III
- Posts: 132
- Joined: 07:24 pm Jun 19 2022
- Country: United States
- Location: Fairbanks, Alaska
Re: Test/tune
Great information on testing! I wanted to add something from my KLX650R tuning and this seems like a good thread for it.
I've been working on leaning that bike out gradually (because it runs pretty great regardless) to increase MPG and get rid of the black smudge on the rear fender. Anyway I went and started off this year with a smaller PJ and MJ(130) on the CVK carb. I put the needle down to the lowest clip position (5). Bike had amazing throttle response through half throttle, ran good everywhere but seemed a little flat at WOT. Well I assumed it was still just a bit rich (and I could see the slightest black revving). So I put in a 125 MJ. Well I lost some of the low throttle response (still pretty good though), but at WOT the bike just broke up completely and wouldn't rev. So I went to lean right? I decided to experiment for a data point before just putting the 130MJ back in and raise the needle to the 2nd clip...... and I'm glad I did! Low throttle response was even better than before and at WOT the bike just kept pulling. So when your tuning just remember that every circuit affects fuel flow at every throttle position. Not as much as the 'primary' circuit for that particular throttle position, but it doesn't hurt to try something against the conventional wisdom a little bit.
Now on to tuning my fresh 225 top end on my KDX 200!
I've been working on leaning that bike out gradually (because it runs pretty great regardless) to increase MPG and get rid of the black smudge on the rear fender. Anyway I went and started off this year with a smaller PJ and MJ(130) on the CVK carb. I put the needle down to the lowest clip position (5). Bike had amazing throttle response through half throttle, ran good everywhere but seemed a little flat at WOT. Well I assumed it was still just a bit rich (and I could see the slightest black revving). So I put in a 125 MJ. Well I lost some of the low throttle response (still pretty good though), but at WOT the bike just broke up completely and wouldn't rev. So I went to lean right? I decided to experiment for a data point before just putting the 130MJ back in and raise the needle to the 2nd clip...... and I'm glad I did! Low throttle response was even better than before and at WOT the bike just kept pulling. So when your tuning just remember that every circuit affects fuel flow at every throttle position. Not as much as the 'primary' circuit for that particular throttle position, but it doesn't hurt to try something against the conventional wisdom a little bit.
Now on to tuning my fresh 225 top end on my KDX 200!