1984 KDX Jetting Get me in the ballpark

[wfopete]

As talked in a earlier post my 200 is hurting on low end and mid range power. Top end power is super strong and crazy fast.

I pulled the brass today and have the following:

PJ 35

MJ 280

Slide 3.0

Needle 5FJ57

Needle Jet R-6

I would like to know what the OEM jetting was and if these pieces listed are way off.

The MJ seems lean for this bike as I have seen some with 330 MJ and could explain in part the poor low end/mid range power.

I would really like to know the correct needle and needle jet sizes.

My Clymer manual shows the 83 model with a 135 MJ but the 84-85 with a 260 MJ and the 86 model jumps to a 300MJ.

My Needle appears correct for the 84 year so that's good.

PJ is listed as a 40 I'm running a 35

The listed Needle Jet (R-6) which is what I have.

Thanks,

[KDXGarage]

Here is a parts diagram, showing the 1983 and 1984 carbs.

https://www.partzilla.com/catalog/kawas ... x200-a1-a2

Where are you, USA? Going up two sizes on the main in the summer should be real rich, I would imagine. You are down two sizes on the pilot.

At least you don't have to worry about clogged power valves.

What is the engine and air filter condition??

[wfopete]

Yeah, PVs no thanks at least with that KIPS version. I'm in Arkansas and it's pretty thick and hot here. The last I raced/rode the bike was in Ohio with temps in the 80's but the bike has always run like this since I bought it. It doesn't show any typical signs of an air leak(s) and no excess smoke from the exhaust. I run ATF in the tranny so if the clutch side crank seal was bad it would be obvious with burning ATF. The next time I have it running I'll do some checks around the intake/base gasket area and give a shot of starting fluid to the crank seal on the flywheel side too. Pulled the plug for a look (no proper plug chop) and it's about what I expected (more black than brown) after a 1 hour hare scramble and riding around the pits for 15 minutes. Same for the air filter; a little dirt but not nearly enough to impact the running of the bike.

Currently I have the stator and flywheel soaking in a vinegar bath to remove some light corrosion before I test the stator. Recently I replaced the ignition of a 72 XL250 Honda with an HPI kit and it went from zero to hero for spark due to a bad stator, I don't think this is the case here but it never hurts to verify the specs.

[wfopete]

Been messing with the KDX in the cooler morning hours. Got the fork springs dialed in and they seem pretty stiff after the first few inches of travel. Checked my 1985 KTM 250 "Zokes" and they are the same diameter. The Zokes were always nice and plush so there could be a fork swap in the future. Pulled the nasty stator off, gave it a several day vinegar soak, disassembled and cleaned the corrosion off it. Should have tested it before I pulled it off the bike but I didn't. Tested once cleaned and back on the bike and the numbers were out of spec so it makes me wonder how much of this, if any, is impacting the power. Also retarded the timing a bit so now the timing marks line up. Did find a fair amount of corrosion in and around the ignition case and stator though. The motor had seen a lot of water in there at some point.

Black to Blue Spec 104 measured 180

Black to White/Red Spec 38 measured .20

Blue to White/Red Spec 142 measured 24

Black to Yellow Spec .54 measured .7

Also pulled the carb to make sure jetting was ok; it was. Compression was just "ok" at 150psi. Put in all back together and it started fine. Rode it around a bit to see if anything changed much. Couldn't really tell and really wasn't expecting to feel much difference on a short driveway run. The engine may be making more low end but with the temps and humidity now the bike is running a bit on the rich side. Yesterday we broke 105 but today is much cooler; only 100. Plenty to go bad with electrics on a old bike. Complete aftermarket ignitions are available ($300~) but for now I'll wait on that and run it a bit first.