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Picked up my sons 2007 CR 125 today..

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What a great little bike! Stock the jetting is way rich down low (as you all know) so i had a JD jet kit ready and before we even rode I installed it:

Blue needle, second clip, 420 main, 32.5 pilot.

I ended up with the air screw at 1.5 turns out and this thing runs perfect! crisp, no bog and it gets right into the powerband :) had to adjust the idle and thats it.

My son is very happy....me, I will stay with my 500AF, lol

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Congratulations on the new bike. Post some pics if you get the chance. 👍

Will do after I get his numbers from decal works, hehe :worthy:

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The 32.5 isnt too lean?

No...no issues at all...crisp throttle repsonse. When you get on it it gets right into the powerband and rips.

I went with the Blue needle second clip, which is slightly richer then the red needle on the third clip just for safety reasons. It runs great. I did notice that if I set the air screw at 13/4 like JD recommened, it would bog a big when snapping the throttle but I moved it to 1.5 turns out and it is perfect. 👍

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It just seems like a huge drop from the standard 55 pilot.

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It just seems like a huge drop from the standard 55 pilot.

That's what comes in the JD jet kit and yes, thats how far off the stock jetting is:eek: They are known to foul plugs stock.

The JD jet kit also changes the 430 main to a 420 so its really mainly in the needle and pilot.👍

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I rejetted my 05 cr125 which is the samething as the 06 and 07's but i am running a 50 pilot jet and a 410 main jet with the air screw 1.5 turns out and i get instante throttle response. I have been running it 32:1 with a br8es and it runs perfect no bog what so ever.

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my 06 125 will load up and almost die if u let it idle 4 like 30 sec,if i put a 33.5 pilot in it would it help.im running 50:1 92 octane and my jetting now is :main 420,pilot 55,airscrew 2 1/2,and my needle is stock and the clip is on the very top. any help would be awsome

oh ya and im at 3400 alt.

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my 06 125 will load up and almost die if u let it idle 4 like 30 sec,if i put a 33.5 pilot in it would it help.im running 50:1 92 octane and my jetting now is :main 420,pilot 55,airscrew 2 1/2,and my needle is stock and the clip is on the very top. any help would be awsome

oh ya and im at 3400 alt.

Well the 05-07 are the same exact bikes motor mise frame wise everything except the shroud graphics on the 2007 are different. But mixing a 125 50:1 is just a ticking time bomb waiting to happen. 125's are always on the gun unlike the 250 2t. So what i would do if i were you i would do what i did. But thats because my bike hasnt fouled a plug yet and it hasnt blown up in the past 6 months. First get a 410 main jet and a 50 pilot jet. Since the needle is stock just leave it where it is (second clip). Now when you have the pilot and main jet in turn the air screw in all the way until it stops. (dont to hard it has a spring in there you'll know when its supposed to stop) now turn it out 1.5 turns. Use a 32:1 oil ratio and run a br8 plug. br8es br8eg br8ev whatever br8 plug you like. Your bike will run like a dream with no bog and no jd jetting to screw around with.

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But mixing a 125 50:1 is just a ticking time bomb waiting to happen

yea right tell that to my friend who constantly does it and has an eric gorr '06 CR 139 ported for mid/top and high compression head. 50:1 all day with race gas his motor is twice as hard on pistons now then it ever was as a 125 but it has never siezed pistons look great cylinder wear is great.

32:1 is premixing recommendations from like the 70's oil are how much better now all new KTM's say like 40:1 or 50:1 recommended.

I run my '06 YZ 144 at 40:1 no problems

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