Posts
514
Joined
12/15/2014
Location
Riverside, CA, USA
2023 yz125 4hrs on the bike. rode it a bit last year and parked it till last weekend. been doing the vintage moto thing mostly. brand new everything was good but could tell it was a bit tight when shifting into 2nd. after I put an hour on it I changed the trans oil. used redline 10-30wt. put a couple more hrs on it and never an issue, then sat at Glen Helen as i pulled onto the track it was like WTF! it was not wanting to shift for shit under a load. any of you had an issue with yours. also drop your jetting spec if you can remember it. gas, premix, ratio. thanks.
Just might need more time to break in. My 24 was really "notchy" and hard to find neutral. Changed the oil after a few hours and now shifts good.
Jetting - JD Jet kit, blue (rich) needle, clip 4th position, 52 pilot, 172 main, Sunoco 100 oct at 40:1.
10-30w ? Trans oil is usually 80-90w. I used to change oil every ride even on hard pack tracks. When the oil was 1.99 . Now it’s every other ride.
Dabbing the clutch or blipping the throttle?
the yz125 is a bit "different" than most. ours for instance, both of the require a very controlled and precise shift into neutral whether the engine is running or not. Unlike our yz250f which clicks right into neutral without issue. The 125's are a 23 and a 24
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I had a KTM 2 stroke that had the same issue. 2nd to 3rd under full gas, it just wouldn't take the shift.
Eventually, I ghost rode it into the pacific ocean. Actually, between the shitty fork and the sticky shift, we parted ways.
Sorry, I offer no advice, just same frustration.
It might get a bit better with some more break in time. Mine still has trouble with shifting from 3rd to 4th under a particular RPM/load. I've developed a feel for it and can somewhat predict when it will be a problem. I can avoid the missed shift by blipping the throttle or shifting a little early, but neither of those are ideal workarounds when riding a 125.
As for jetting, I went to a 50 pilot, 170 main, stock needle and clip position. I was fouling plugs like crazy the way it was jetted from the factory, but it runs nice and clean now.
Haven't noticed this issue on my 22. I've been using Maxima MTL-R 80wt in the gearbox.
VPR and motul 800 2t @ 32:1. #6 slide, 55 pilot, CCL needle-4, 182 main, 35 powerjet
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