I have a 2007 KLX250S and have installed the KLX300 piston and cylinder.
Also installed a FSW header pipe and a KLX300 muffler with restrictive end core removed.
In checking OEM camshaft part number I see that the KLX300 has a different exhaust cam
2007 KLX250S exhaust cam 12044-1365
2007 KLX300 exhaust can 12044-1487

Has anyone installed the 300 cam in the 250?
Is there enough performance gain to do this?

Has anyone installed Web cams (without having to change valve springs) and can report on performance gains.

thanks
Doug

 

I didn't think the Larry Roessler model Web Cams required any spring change. I think they had 2 other models that did. It seemed like the grind on the LR versions was a much more realistic cam for most riding conditions.

On the KLX300 cam having a different part number, it may indeed have a different grind, but you can't use that number as an indicator of true performance difference. It could be like using the head numbers to indicate a performance difference when the the 300 is different because of the fresh air injection on the 250 model. If were going to go with aftermarket cams, I'd go with the LR Web Cams.

 

good to know TNC have you ever driven a bike with cams? I am just wondering how reliable/ easy to start etc they are.. I too am interested in LR grind web cams

 

I had one of those original '79 KLX250 air cooled models with a Powroll cam, and with the pipe and jetting, it gained a decent punch. It remained a 250 because I was in the 250 enduro class. A buddy in the open class had a Powroll 318 on his...the biggest offered for that engine...and with his cam, pipe, and jetting, that thing honked.

One of my mid-80's XR250R's had a Powroll cam also, and it picked up a nice punch too. In both cases, I went for a mid-range cam, as that was more beneficial for my riding needs. Neither cam required heavier springs. That LR cam sounds a bit like the same kind of deal.

I had some cams in a roadbike, but that's a different application.

 

I guess I didn't phrase my question correctly.
Given that the 2007 KLX300 has a different exhaust cam (part#) than a 2007 KLX250 has anyone tried putting a KLX300 exhaust cam in a KLX250 engine and what was the outcome.

 

I'm su****ious that we haven't heard much if any commentary about a cam interchange between the 250 and 300. People have put the 300 exhaust on the 250. They've put the 300 cylinder on the 250. I'm betting there's no reason to put the 300 exhaust cam in the 250...performance wise. The difference in the exhaust cam may be nothing more than a tweak in the KACR, because the 300 is kickstart only. But I only speculate.

 

That would be my guess too.

 

Well you never know unless you ask or go out on a limb and try it.

 

This was talked about back in 2007....

https://www.kawasakiforums.com/forum...amshafts-9102/

just thought it worth mentioning.....

 

Thanks that answers my question about the difference in the KLX250 & 300 cams.

If I want improvement in the camshaft area it looks like the aftermarket cams are the way to go.