KDXRIDER.NET

Guys,

Sorry to start another one of these but I'm at my wits end. Here's the deal...I bought a '97 KDX 200 with very few hours on it. Original tires. Beautiful purple seat ;) Frame is barely boot-scuffed. I am at 700-800 ft. in NC. I run 93 octane (with the usual 10% ethanol) and Amsoil premix at 40:. Not one to leave things well enough alone, I decided to do the normal mods. Here's my progression:

1. Bike was on original jetting and pig rich so I started jetting down to get more go. Ditched the airbox lid, threw in a new lightly oiled filter and float checked out in spec. New BR8ES plug. Settled with 42/152 and stock needle in slot 2 from top. AS at 1 1/2. Bike ran much better. Ran this way for a couple of months.
2. I decided to try a set of new Boyesen 607's for fun...Bike was a tad richer with the 607's so I jetted down to 40/152 with needle in same spot. AS at 1 1/2 Bike ran pretty much the same with maybe a little more crispness off idle than step one. Ran this way for a month or so and started looking at pipes.
3. Was given a free lightly used FMF rev pipe so I had to try it. Tried several jet combos and ended up back at 40/152 and needle in 2nd slot. AS at 1 1/2. I like the rev pipe okay although the woods version would better suit my riding style. Bike runs like a raped ape up top and I don't feel like I lost much down low except that bike now has a blubbery spot at 1/2 throttle. It seems fine everywhere else. If I really whack the throttle it will clear out and rev like it should but unfortunately I can't always do that on the trail. I've tried AS positions from 1 to 2 1/2 and it doesn't seem to change things at all. What to do? I am about to put the stock pipe back on and call it done. Ideas?

Based on the jet guidelines I've read here and on the other forums I feel like the bike is already jetted on the lean side. Am I in need of a different needle? Do I need to RB my carb? Anybody else had this problem when going to a rev pipe on a 200? By all means chime in!

I would start moving the needle clip up leaning it out in the mid,one at a time. Needle and slide control the mid throttle position.

I moved the needle clip to the first slot (leanest) and it cleared the blubbery mid right up. Is it just me or does it seem like my bike prefers to be way leaner than most others on the forum? '97 2Hunny, 40/152, stock needle in top (leanest) position, Amsoil 40:1, <1000' elevation @50 degrees temp., no airbox lid, Boyesen 607 reeds and FMF rev pipe. WOT Plug chops look good so I guess I'm okay....

A lot of things affect jetting. Elevation, humidity, barometric pressure, and fuel. Plus, every bike is a bit different. If everything checks out good with a plug chop then don't worry about it.

this summer u will Prob have to go to a leaner needle. Most posted guidelines are just that a starting point. There are a lot of variables just jet bike to the fuel oil and riding conditions you use.

Change your jet block gasket.

Musclegarunt wrote:Change your jet block gasket.

Hmmmmmmmmm...................... Maybe that's it. The bike is running great now but it seems to be jetted really lean (40/152 with needle in leanest clip position) for my altitude and mods. Maybe I'll try the jet block gaskets. I guess leaky gaskets will let unmetered fuel get past? Anybody know where to find these little buggers?

ROADSTR6 wrote: Anybody know where to find these little buggers?

http://www.jetsrus.com/individual_parts/021_532_su.html

Got 'em on order. Any special tricks to installing these? I read a couple of threads on this and it appears that you need some sort of adhesive to "glue" the gaskets to the jet block to hold them in place while you're putting it back together. What works best? I've got some permatex gasket sealer. It is in a metal can with a brush on the lid. Would that work?

There are 2 safety torx screw that hold the plate on before you can get to the gasket. You'll need some safety torx screwdrivers or get rid of the little "pins" in the center of the screws. I dremeled mine off in order to use a regular torx screwdriver to remove the screws.

I've read where others have used glue to hold the gasket in place in order to get them to stay in place during reassembly, but I was able to line everything up without using any adhesive.

10-4. I've got the proper safety torx bits so I guess I'm good to go. I hope this puts an end to my jetting issues. Even if it doesn't I'll feel better knowing that the 15 y/o gaskets have been replaced. I'll keep everyone posted....

Changed the jet block gasket yesterday. It made no noticable difference. I was so sure that it was going to be night and day that I went up on my jets from 152/40 to 155/45 and dammit it's rich. I'm going to jet down to 152/42 and try that. The bike runs strong on the 155/45 combo but I ruined a shirt and a pair of pants with all the little black specks spooging from my silencer... I think maybe jetting down one more step will put me in the ballpark.

do you lose gear oil when you ride? check the level before you ride and see if it is lower at the end of the ride. you may have a bad crank seal on the clutch side

No. The case oil level stays constant. I will keep an eye on it though.

did you ever solve this case?!?! I am having similar issues. I seem to have a rich environment no matter what I do. I would like to lean out a little more but dont know where to get jets for my carb smaller than 42/155. Im interested to know how you came out and know where to get smaller jets.