Can't rev past 12000 rpm while in gear
 

Hey everyone,

I own a klx250 with a bill blue 351 cc kit installed. Since purchasing the bike I havent been able to accelerate past 7000 rpms while in gear. Up until 7000 rpms it feels smooth, but it quickly runs out of power and begins to feel wrung out. My KLX250 at 7000rpms feels similar to my klr650 running at redline.

While in neutral I can easily excede 7000 rpms and the engine still feels smooth. I should also add that the previous owner installed a smaller front sprocket.

If anyone has any idea of what the issue could be, I'd appreciate your input.

Thanks,
Canehdan

Tell us more. Exhaust system and jetting mods? Air box lid on or off?

"Can't rev past 12000 rpm while in gear"
Really? The limiter kicks in at 10500.
Strange thread title since the problem is at 7000 rpm.

Got you to look didn't it???

Fueling issues could cause these symptoms but I would take a close look at the cam timing to make sure that everything was installed correctly. If the cams are not phased properly then it can result in the symptoms you are describing.

If it is an EFI bike it has a rev limiter in 4-5-6 gears to 7k. Easy fix by bridging the clutch lever switch.

is it efi???

Thanks for the replies everyone! And sorry about the thread title.

As for mods it has the 351cc kit, a hindle exhaust and the airbox lid is removed. The PO knew little about the bike so Im not sure about the jetting, however I live at an altitude of 3500 ft and still experience a fair bit of lean popping.

Lets hope its not a timing issues GBAUTO. It might actually be a fuelling issue though. The bike had sat in the PO's garage for a while so the carb is probably pretty gummed up.

Also the bike is carbureted, not efi.

Thanks for help guys.

Canehdian

Two thoughts...
It's quite frequent that aftermarket exhausts pop due to small air leaks and not lean conditions. Mine did until I got the header/slipon joint fully sealed.

When first installing the dynojet ket on stock 250, I followed other's instructions and installed main and pilot jets that were way oversized. The pilot was 38 and main was 128 or 132. The bike would not get much above 8000 or so RPM. With the air box lid on it was closer to 5500 to 6500 rpm and would just fall on its face (richer with the lid on). It needed leaned up. Not saying this IS your problem, but it could be. You should open up the carb for an inspection and see how its jetted. Put some fresh fuel in also if you've not done that already.

You need to jet it I'd guess, my big bore kit required 38 pilot and about the equivalent of a 136 dynojet, but my elevation is less than yours. My bike was dead above 8k with a 132 dynojet in it and needed a couple steps up to pull to redline.

Thanks again for the replies.

Hmm ive never heard of that IDRIDR. Ill have to look into that on my other bike as well. Im also kind of lost when it comes to jetting so ill probably have to take it into a shop.

Thanks