Hello Everyone! Just wanted to tell you about the results of putting in JD Jetting for my son's and my CR125. Before the jetting changes, the bike would smoke, foul plugs, and have to constantly be revved to clear out the engine. I put the main jet and pilot jet in from JD as described in the kit. Needle was supposed to be set in the middle (3rd position) with the 420 main and 32.5 pilot. When I started the bike with these settings, the bike ran a bit better than the previous stock settings. So I did what others had done and the results were night and day. Here is what I went with:
Needle: Red needle 2nd position from top
Main: 410 (came with the kit)
Pilot: 32.5 (came with kit)
Air mixture: 2 turns out
After using these settings, the bike barely smoked, ran crisply, and felt strong throughout the throttle. Cannot believe the difference. If you have this bike or the late model CR125s, get this kit. I know many people complain about the cost, however the bike feels totally different now. Hope this helps someone out!
Sure beats swapping multiple needles, testing, swapping, testing, etc. JD kits are mostly good and generally a real time saver too. Some folks like the headache of the jetting process. Time is more valuable to me. Some bikes have a good, known non JD set up, that is great too.
Yeah, that is how I see it as well. My son just got done riding the bike after the changes and he really felt a huge difference. After reading previous posts, I just knew I was not going to get the results with that stock needle. Still need to take the bike out to a track or the desert to really test it out, but I feel much better now riding far away from the truck instead of worrying about fouling a plug. The bike even sounds stronger. Much throatier if you know what I mean.
The Shop
I haven’t installed the slide yet. But I,m sure it fits . Here’s the part #
Thanks for the tips! I did notice that the slide has one ever so slight spot that is not chrome. However, I don't think it is a problem. Might have to go with the slide eventually so thanks for the advice! When I pull the top end, I will definitely do the PV the HRC way. By the way, I took off the PV covers and one side was installed incorrectly and the pipe side of the PV had no nut or washer. I used a magnet and found the nut and washer down in the cavity. Luckily they did not find their way down into the engine!
If you ovr tighten that rt side nut the pv doesn’t move as free. The left side part that fits in the pv shaft groove would keep it from backing out. I put lock tight on the rt side nut & don’t tighten it much. I use a 13mm socket with a tape to hold it in the exhaust port. For the hrc pv adjustment. Just pull the pipe. The 04 has its own air boot. I installed a 05-07 air boot on 1 04. It adds response low to mid & runs clean to the top. Then installed the power flow alum cage. It gained throttle response & runs real clean to the ovr rev , a increase bottom to top. The 04 boot has a harder hit I like that too & keeping it on the practice bike which I tried to sell but can’t.
I updated my phone now I can’t upload pics. I use a long 13mm then wrap black tape until it fits & stays in the exhaust port. For the hrc pv adjustment.
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