96 KDX 200 help

Joined
Dec 8, 2006
Messages
9
Likes
0
#1
Just bought a 96 KDX 200 that's all stock. The previous owner told me it didn't run very well and hence I got it for a very good price.

Here's the problem - the bike won't idle. I've got the throttle stop all the way in. Also won't pull cleanly to redline. It's obviously loading up and rich (black spooge and fouling plugs), but I can't seem to figure out why.

Here's what I've done and checked so far -

Drained fuel tank and mixed fresh gas with yamalube R @ 32:1

Cleaned carb. Checked pilot and main jet for blockage. Checked all the circuits with carb cleaner to make sure they were clear.

New float needle and seat

Checked floats - they still float :laugh:

Main jet - 155
Pilot jet - 42
Needle clip - middle slot
Air screw - 2 1/2 turns out
Float height - 16mm
Compression - 150psi

New NGK BR8ES (several ;) )

Cleaned the air filter.

Checked for cracks around intake boot. Sprayed WD-40 around with bike running, but no change in RPM to indicate an air leak

Pulled the flywheel cover to see if there was evidence of a crankshaft seal leak, but I don't see any black stuff there. I don't appear to be losing any transmission oil either.

Looking through previous posts, it appears I'm pretty close on the jetting. I started jetting down on the main jet today just to see what would happen. The bike ran a little better for every size down I went. When I got to a 138 the bike pulled cleanly through to redline. I'm sure if I go with a smaller pilot jet, I'll get it to idle. I'm afraid I'm headed down the wrong road by jetting that far down. A 138 main jet seems to small to me. I suspect I would just be covering up a problem. I'd rather fix it correctly.

I've exhausted my knowledge. Anyone have an idea?
 
Joined
Dec 8, 2006
Messages
9
Likes
0
#2
Update - I borrowed and installed the carb off my buddies 03 KDX 220 and it ran great. The jetting on the 220 carb is nearly identical to mine. So, I guess the problem is in my carb. Now the question is what? I've replaced my float needle and cleaned the carb really good. I was able to blow carb cleaner through all the circuits. Guess I'll go back and do it again. If anyone has any suggestions, I would greatly appreciate it.
 
Joined
Dec 6, 2006
Messages
36
Likes
0
#3
Maybe your richener jet(choke) is leaking. If it's dripping all the time it can do the same thing. I had that happen on my old DT175. I screwed around for quite a while until I figured it out.
Joe
 
Joined
Mar 24, 2006
Messages
324
Likes
0
#5
if it ran perfect with the 220 carb, it must be carb related. Like joe said check the choke, just put a little pressure on the choke plunger to help seal it up if it is actually leaking.

on a side note, RZ mike, you gots an RZ? whatcha got? :cool:
 
Joined
Dec 8, 2006
Messages
9
Likes
0
#6
Well, it wasn't the choke either. I've taken each replaceable part from the 220 carb and exchanged them with my 200 carb. Nothing seems to help. I guess my carb is just toast. Must be something worn, beat, or warped that I can't see. I think I'm going to see if I can locate a new or used one.

Yes, I've gots some RZ's - a RZ350 and RZ500. Ride 'em all the time. Got 2 more RZ350's waiting to be finished. No museum restoration, just getting them roadworthy. And I've still got several RD's as well, but none of them run. They are all waiting for attention. If you haven't noticed - I'm a sucker for 2 strokes. :)
 

WoodsRider

Sponsoring Member<BR>Club Moderator
Damn Yankees
Joined
Oct 13, 1999
Messages
2,812
Likes
0
#7
Friend of mine had a similar problem with a GG250 (Keihn PWK38). The bike was fouling plugs with a 155 main, even though the stock main is a 178.

Turns out there's a deflector around the main jet on the air-box side in the bottom of the carb bore. On his bike the deflector was broken off. He replaced the carb and the bike ran great with a 178 main.
 
Joined
Mar 24, 2006
Messages
324
Likes
0
#8
RZMike said:
Yes, I've gots some RZ's - a RZ350 and RZ500. Ride 'em all the time. Got 2 more RZ350's waiting to be finished. No museum restoration, just getting them roadworthy. And I've still got several RD's as well, but none of them run. They are all waiting for attention. If you haven't noticed - I'm a sucker for 2 strokes. :)
hell yeah man, im building my first RZ500 right now, im the same way, 2 stroke whore, i just picked up a waterbuffalo and a gt380. had a few RDs back in HS. got any pics? sorry for the off topic BTW
 
Joined
Dec 8, 2006
Messages
9
Likes
0
#9
WoodsRider said:
Turns out there's a deflector around the main jet on the air-box side in the bottom of the carb bore. On his bike the deflector was broken off. He replaced the carb and the bike ran great with a 178 main.
Good idea WoodsRider. I hadn't thought of that. I checked it this afternoon and the shroud is still there and intact.


ZOMBIE666 said:
hell yeah man, im building my first RZ500 right now, im the same way, 2 stroke whore, i just picked up a waterbuffalo and a gt380. had a few RDs back in HS. got any pics? sorry for the off topic BTW
Suzuki GTs......I had a GT250 back in high school. Rode it through college. It's still in the back of my dad's garage I think.

There's some pics on my website.

Most of the stuff on there is dated. I haven't done much with the site in awhile.