Added reply in a thread Jetting help for 2007 KX250 8/18/2020 6:39 AM

I see what he is trying to do there, but That is Still going to be one hard hitting engine into mid with that series needle. There is no getting around it, and still have the bike running cleanly off the bottom. I’m taking into account that the majority ... more »

Added reply in a thread KTM/HUS 125/150/250 jetting thread 8/13/2020 8:11 PM

He could certainly try backing the air screw out as well, but It sounds like he's into an off idle bog situation , which is typical of a needle that has a starting diameter or 1st taper that is too lean. If it was rich, I would expect more of a stutter ... more »

Added reply in a thread KTM/HUS 125/150/250 jetting thread 8/13/2020 7:45 PM

Try turning in the air screw, and if it doesn't get better, move the clip to the 4th position. if still not better try using a richer pilot. Do you have access to a dial/digital caliper and a round file ? Look at the slide above that I cut. That all ... more »

Added reply in a thread KTM/HUS 125/150/250 jetting thread 8/13/2020 7:13 PM

What clip position is the needle in now ? Change the clip position to a richer setting. Turn the air screw in and or change the pilot( richer/larger). Notch the front side of the slide like the above pic. The jet block gasket really need to be replaced ... more »

Added reply in a thread KTM/HUS 125/150/250 jetting thread 8/13/2020 5:34 PM

The 42-75 needle is to lean for your 125. You should be using a 42-74, which is one size richer on the starting diameter. I also recommend that you open up the front side notch on the slide. It seems to be more beneficial on the 125/150's. Have you replaced ... more »

Added reply in a thread Jetting help for 2007 KX250 8/9/2020 1:11 PM

It looks like you have a pretty good handle on it now. Nice job.

Added reply in a thread Jetting help for 2007 KX250 8/3/2020 10:27 AM

I think your best bet for a quality low flashpoint premix oil might be Torco's GP-7. It has a flashpoint about 30 degs less than the Motul 710 and almost 100 degs less than the Yamalube. I would also use the least amount of c-12 that you can get away ... more »

Added reply in a thread Jetting help for 2007 KX250 8/3/2020 9:03 AM

I don't really take much stock in reading plugs. There is just too much variation. I go by how the bike/engine feels feels and reacts. The pic of the plug you have above does look almost perfect though. I don't really have any experience with Motul 2t ... more »

Added reply in a thread KTM/HUS 125/150/250 jetting thread 7/30/2020 6:33 AM

I use a round 5/32 or 4mm chainsaw file to enlarge/create the notch on the reed side. It’s about 2.75 to 3mm deep. You do not have to be super precise with it. Just get it close to the pic I posted and you’ll be good.

Added reply in a thread KTM/HUS 125/150/250 jetting thread 7/29/2020 12:28 PM

Listen to AJ, he has an sx250 and is still refining his setup, The slide that you cut, sounds exactly as to how I cut mine. Here’s one that I cut today for someone.

Added reply in a thread JD Jetting red/blue needles 7/13/2020 9:06 PM

The std JD needles are too lean, as you have found out. The last KDX 200 that I set up, summer temps, and sea level elevation. I used a Honda 695 or 685 /294 needle in the #3 clip, a 42 pilot, 148 main, and cut the slide to a #7. This setup worked very ... more »

Added reply in a thread JD Jetting red/blue needles 7/13/2020 8:31 PM

Actually, I believe he sells 3 Red needles and 2 Blue needles for Keihin PWk's. The variant is the amount to colored scribe lines that are under the clip position. One set, red & blue, are for the STIC jet block, and he also has another red needle ... more »

Added reply in a thread Squish 250yz to tight? 7/12/2020 7:52 PM

That 1.14mm squish will be fine, from a mechanical stand point. Just be aware that you are more than likely going to need to use some race fuel, depending on what the heads combustion chamber volume is.

Added reply in a thread KTM 150 Carb Swap 7/12/2020 6:27 PM

Slide---#7 Needle-- CCL in the #3 clip position Pilot---48 Main---178 airscrew----1.5 This will get you well within ballpark.

Added reply in a thread TMR295 kit jetting 7/12/2020 6:20 PM

A #8 slide works great in the YZ250 in general, but you must use a different cable holder in it. If you use your Yamaha spring loaded holder in a non Yamaha spec slide it WILL break the needle. Your Yamaha slide has an S stamped into which denotes that ... more »

Added reply in a thread Anyone have a TM 300 4t? 7/12/2020 6:03 PM

I have a Redmoto 300cc kit on my 19'crf. It's bone stock, with the exception on the BB kit, and reprogrammed ecu for the BB. I have yet to ride a 250f that is comparable, power and torque wise to my 300cc crf. It's a great package. For the price of the ... more »

Added reply in a thread TMR295 kit jetting 7/12/2020 2:12 AM

The above setup would be for your current temps and sea level to 1500 elevation

Added reply in a thread TMR295 kit jetting 7/11/2020 5:07 PM

This will get you very close. Needle—Suzuki NEDJ in clip #2 If you do use this needle, you will also have to replace the oem Yamaha throttle cable holder, the part that screw into the top of the slide, With one from JD jetting or from a Kawasaki. Pilots—40 ... more »

Added reply in a thread Jetting help for 2007 KX250 7/7/2020 7:41 AM

With the low compression head, you more than likely don't even need any race fuel to prevent detonation, which is what I would be worried about. I do all my test/riding at 40:1, which is 16oz of oil in 5 gal of fuel. Simply for consistency, I never change ... more »

Added reply in a thread Jetting help for 2007 KX250 7/6/2020 4:24 PM

I typically cut my fuel, 4 gal 93 octane, 1 gal of 110, but I don’t know where your squish is with your aftermarket head. kX’s always had high crank pressure, so it’s possible you may needs a touch more race fuel, say 3.5 to 1.5 to be on the safe side. ... more »