hello all,
i dont post here much but, i have a 01 klx300 and on the subject of the kacr, up to 2003
the kacr was clocked wrong on the exhaust cam wich started wearing the idler gear bearing out. once reclocked it started easier, and easier on idler gear for the kick starter.
so you can press off the kacr on klx300 exhaust cams. you cant remove the whole assy on the 06 klx250s which i have, ive replaced a couple exhaust cams on my 300 because of this kacr, if they let loose motor gone!!!!!. i have not put a 300 cam without the kacr assy removed, but the next valve adjustment, i will use a old 300 cam with the kacr removed. see how it works. one last thing if you have a kick starter on , DO NOT RUN WITHOUT KACR ON EXHAUST CAM. will wear out idler gear very fast and if it lets go no more motor. been there done that.

Can you explain the logic behind that? I'm not understanding.
The KACR reduces compression (by holding an exhaust valve open), so that the starter motor doesn't have to labor so much when turning over the motor.

With a kick starter, your leg muscle can overcome the compression easier than the starter motor can. How does this have anything to do with the idler gear wearing out?

The idler gear bearing for the kick start mech. at least on the 300 is paper thin and starts to wear out with the extra load placed on it from, no kacr assy. when that happens the gear starts rocking on the shaft and breaks teeth off or splits in half, then metal pieces go through your engine. when stroker was still in business they made a stronger bearing and gear for the 300. the idler gear sits on a shaft between the kick start shaft and the clutch basket. there is a certain way to start a 300 if not followed it puts undo stress on that gear.im sure the 250 has the same kick start mech.

this was one of the main issues with the 300, you have to keep an eye on the idler gear bearing and replace it, then when people started putting big bore kits and cams it just made it worse. if you look on parts fische. youll see this gear it takes all the load from kit start.

OK, so the idea is that the missing KACR puts more strain on the idler gear when you kick the bike over? I have to admit that I don't know exactly what role the idler gear plays.
Is it only for kicking over? Or is it always in action?

Here's a link that shows the infamous broken idler gear. If the teeth break like this you are very lucky when the motor survives. You must find every broken piece which often requires splitting the cases.



http://www.thumpertalk.com/forum/sho...=675448&page=2

Lots of teeth missing in that pic.

Is this a problem that the 09s share?

In theory yes, same idler gear. Never seen that problem before or heard about it, till now.

For reference a pic of my idler gear during install of a kickstarter on an 06 klx250....same motor you 09 boys got. I have no intention of removing the compression release gizmo.... F it :D

Attachment 24428

The only time you have to worry about the 'idle' gear, (not 'idler,' contrary to popular belief), is when you have a kick starter installed. After a certain year, the KLX300 ACR was re-timed to put less pressure on the idle gear, which aslo made the bike easier to kickover. This also made the bike much easier to start, so the mod was named 'EZ start.'

Kawi still uses the pre-mod KLX300 exhaust cam part number on the 2006/7 KLX250s.

I you have installed a kick starter on your KLX250s and use it often, I'd probably be worried about it. If you only use it for a back-up, no big deal. I'd still inspect the idle gear from time to time though.

The first thing the happens is the bearing starts to wear, then the gear assy cracks due to uneven pressure. Once a chunk of that gear comes loose, it could get expensive real fast.

Tremor, the idle gear does not come with our klx ... it is part of the kickstart kit....so obviously it would not be a problem without the kickstarter because it would not exist.

Post up some links to klx 300's having this problem a lot, I think this is a bs concern....klx 300's have been around for over a decade....where are the mass failures.