Given the amount of mechanical work performed, I'd do a compression check or leak down test. Make sure you're not chasing a hard parts problem.

Erratic idle sounds like the slow circuit in the carb isn't flowing any fuel.



.

 

Who runs their bike out of oil?

 

I tried this, and the slide isn't moving when revved up to 5-6k rpm (I hesitate to go any higher). At what RPM have you guys tried this and seen it move?
-It's possible the slide is sticking. I literally had to polish the plastic slide because it was deteriorated from sitting in the Arizona sun for a year. I was pretty diligent about this (I was still waiting for the 351 kit to arrive so I wasn't rushing) but a mark can still be seen where it was exposed.

or
Vacuum leak - also possible, but I followed the instructions in the block off thread pretty thouroughly. Besides a block off plate, the gas tank vent lines, carb line, airbox plugs all new and snug parts. I'm really not sure where else it could be coming from if this is the case?

I'm pulling the carb now, and probably going to change the main jet while I'm at it. I chose the DJ 124 based on plans to get a pipe, but it may be a month or two away. I'm going to lean it up a bit and see if that helps.

 

I run a dj128 on a 250 at sea level. you've got 351 so I would say you're too lean. What elevation are you? The plastic slide needs slide smoothly,that may be your problem.
marc

 

Maybe there is a problem with the diaphram part of the slide/carb. If there is a hole in it and its letting air pass that would for sure screw things up. With all the other money you spent maybe you should just buy a new one.

 

I have the 250 still without air box lid and new pipe (stock header) and I run 124 main jet at 2000 ft. I think you are way too lean. Always go fat before you go lean.


If you go fat you can always come back. If you go too lean you die

 

Kawasaki Genuine Carburetor Diaphram Valve Kawasaki LAKOTA Prarie ZR 7S KLX250R | eBay

 

You guys are quick to spend my money! haha. The rubber boot portion is fine, and the slide moves up and down easily. I'll repeat my question about anybody else pulling the airbox boot - can you guys see the slide move up? If so, at what RPM?

As for being too lean - I thought that a stutter under power usually meant it was running rich? I'm only 700 ft above sea level. I may have the 351 kit but keep in mind I'm running the stock pipe.

 

7000 rpm ain't nuttin. That is just off idle (okay a little higher) and cruise rpm for this thing. I would not hesitate to hold 7000 rpm in neutral.

When verifying that the slide is sliding. You need to really wick the throttle open fast. The slide will come up for only a brief time as the engine accelerates and then come back down once at high rpm. Only a slight amount of air/fuel mix is needed to maintain 7000 rpm with no load.

No crank damage? He ran it out of oil, wow.

 

I am running a 351 with stock pipe, no problems. I like the peace & quiet & like to sneak around unknown areas.

But I have a slide carb. As stated above really twist the throttle hard & fast to see if the slide is moving, once the rpms' level out, the slide will have dropped back down to limit fuel. Maybe you can use your finger and feel it move, but that may hinder it, i don't know how strong the action is.