to Jd jet kit or not?

[CRipper]

Hey, I'm having some jetting issues fouling plugs and the bike running overall rich.

I haven't pulled the carb off yet to get the current jetting on the bike due to time.

I'm debating between buying the JD jet kit or adjusting my factory setup.

So basically I'm wondering is it worth the money for a JD jet kit or can I achieve similiar preformance by adjusting my factory jetting? The bike is a 04 cr250 and I have knowledge on how to change jetting.

thanks

[crider400]

Just buy some am jets from rm or oem and go down a main jet 1 at a time. What is the color of the plug? What kind of riding?

[rolandk]

I've been playing with the oem jets on my '03 and got it pretty close. I'll probably try a JD kit at some point but I don't think its a must.

[eyesky2002]

The JD kit is what they "feel" is the proper jetting for the application, could be the same you are running. Jetting is based on many factors, elevation, temp, fuel / oil mix and so on. Your best bet is to get a few smaller OEM main and pilot jets and work your way down til you get where you need to be.

Key to remember is that your main only controls the gas flow at wide open throttle, the needle, slide, pilot and air screw do the rest from idle to that point. Seen a lot of people who were running rich down low change out the main and cause a lean condition at WOT.

[K-dogg]

The main problem with the late model CR's is an excessive squish clearance. This makes the jetting very temperamental. For the cost of the jetting kit you can have you head milled to correct the squish. Then jet.

[BurntTimber]

Honestly, for any rider who isn't too confident in changing their own jetting, I'd recommend going with a JD kit anyways. Go with what comes recommended in the box and adjust from there. If you have troubles, the JD site is generally fairly good at getting back to you if you give them details on the setup, riding conditions, an any carb affecting mods (Gnarly pipe etc.)

[MX926]

drop the pilot one, drop the main one, and raise the clip, and that thing will rip...

[jleblanc321]

I have a 2002 CR250R and had the same problem. I got the JD jetting kit and was somewhat satisfied with the results. However, installing a Keihin 38 mm PWK AirStryker (stock carb on a 2000 CR250R) REALLY did the trick. I bought one for $50 that was removed from a 2002 KTM 200EXC (Other KTM's use the same carb.). I only had to rejet it and got the slide machined to a 7.0 cutway (same as a 2000 CR250R) for $20 (includes shipping) by RB-Designs. I would suggest that you do a search for "PWK" or "Keihin" in the "Honda 2-Stroke" Forum for other reviews and jetting suggestions. There are usually a few "AirStrykers" on Ebay and run on average about $125-$150. I found my $50 gem on "ktmtalk.com."

Factoring in the cost for the JD jetting kit (averages about $75), I believe, as many others do including Eric Gorr, that the Keihin is the carb that Honda should have used on the 2001 to 2007 CR250R's from the get go. It idles like a champ and has a much better low-end response.

Hope this helps!

Jay

Edited June 8, 2010 by jleblanc321
typo

[CRipper]

Wow, that was alot of fast responses, thanks for the great info.

Like I stated I know how to jet but before I start writing things down and tearing things apart I figured I'd see if the JD was worth ordering in. I have heard good things about it.

I think ill buy a couple new plugs, take a notepad and find a bare stretch of road somewhere and get an idea where my jetting stands. Using OEM stuff.

I know its running rich down low, not sure about top end.

I'll let ya guys know how it goes!

[Ricky7]

I have a 04 and it was fouling plugs like crazy when I first got it. I went down one on the main and one on the pilot, raised the clip to the top. I also lowered the float height and it hasent fouled since. My bike would leak gas out of one of the over flow vents for the carb when tipped slightly to the side(reason I lowerd the float). I believe lowering the float is what really stopped the plug fouling problem in my case.

[CRipper]

I have a 04 and it was fouling plugs like crazy when I first got it. I went down one on the main and one on the pilot, raised the clip to the top. I also lowered the float height and it hasent fouled since. My bike would leak gas out of one of the over flow vents for the carb when tipped slightly to the side(reason I lowerd the float). I believe lowering the float is what really stopped the plug fouling problem in my case.

Yes! that is what mine is doing, starts leaking gas out of the overflow vent when the bike is tipped just slightly to the side.

Exactly how much did you lower the float? To do that I would bend the float tab away from the floats right? The tab where the fuel needle rests? Never adjusted floats before.