Malves, have you owned the bike since new?

 

Yes! I was so happy when I got it at the dealer. Feels like yesterday.

 

Ok, this morning when riding to the office, I noticed the clutch slipping, but ONLY around 7,000rpm and past that.

Like, suppose I am at 4,000rpm. I twist the throttle quickly to wide open, no slippage until the tach hits 7,000rpm. Ater that, it will slip and then it engages gradually.

The bike is making more power than stock, but would that make the clutch slip? I mean, it's not a big bore kit. It has a Powercore, EJK controller, and modded cams. The bike responded very well to those mods, but still.

Any ideas? This sux.

 

Before installing the 350 kit I had no problems with the clutch. After tho... It slipped in 4,5,6 gears in the upper rpms.

The extra torque/power was too much for the old clutch. I installed the ebc clutch kit and it held up for a short time. But the springs weren't strong enough to hold past 7K rpms.

Looking back I should have installed barnett springs with the big bore kit. I would recommend to install them before you go to the big bore kit.

 

Thanx for the input.

Just to clear things up, I am not installing a big bore on my bike.

 

Your clutch is worn out. You could band aid it with stiffer springs, but fresh friction plates are probably all you need, and if you do the work to change springs you already have done all you need to do to change the plates. The plates are probably cheaper than springs anyway. You'll need to spend a little more if the steel plates are shot (possible if they've been overheated due to too much slipping).

The clutch is a torque transfer device, pure and simple, and it can only transfer so much torque before it starts to slip. For a few reasons, as a clutch wears out, the amount of torque it can transfer decreases. The reason your clutch starts to slip with wide open throttle at 7000 RPM is because that is close to peak torque RPM. As the engine torque slowly declines after peak torque RPM, eventually the clutch regains its ability to hold.

If you keep riding the bike with the clutch slipping, you'll find that the RPM where it starts slipping will get lower and lower as the clutch gets progressively more worn out, with progressively less torque capacity.

If you are using the clutch for your wheelies (and you have to with this bike), yes that is very hard on the clutch, whether it feels like it or not. Actually, every time you use the clutch, it is wearing out a little bit.

 

Thanks for the input, Lutz. Yeah, I was actually thinking might as well change the plates along with the springs. That´s what I'm gonna do, then. OEM or any suggestions? Thanks.

 

I am buying everything tonight. Can someone please tell me if I need to buy 3x the part number 13088? I am not sure if each plate is $16 or if it is that price for a pack with 3 friction plates. Thanks.

2009 Kawasaki KLX250SF KLX250W Parts, 2009 Kawasaki KLX250SF KLX250W OEM Parts - BikeBandit.com

 

Not sure of answer to your question, but I went with the EBC dirt racer kit (springs - not used, friction plate, steel plates) and Barnett springs as recommended by others here. No complaints.

 

Kx125 clutch plates work better supposedly, I've never had the chance to try them. But planet klx recommended them.