351 cc big bore kit (BB)
 

Hi folks -

I am still new to this site so there is probably a thread on this already; what are the reviews of the BB 351 kit ?

I would imagine the 100 cc boost would be fantastic, with no weight gain (no significant weight gain). So :

Pros ?

Cons ?

Any issues ?

Stock carburation work ok ?

My bike has a jet kit and FMF Q4 muffler

Again - thanks for the info ?

Rob

I'm not being a Post Nazi, but you'd probably benefit from reading many of the posts pertaining to the 351 kit. Some say the search engine on this site isn't that great, but I think it usually works well enough to get some research done. You can just sift through enough titles referring to the 351 to get lots of good info. Afterwards you'll probably have some specific questions that need a separate post question from you. You're thinking about spending quite a few bucks on a 351 and possibly some of the normally attached mods that go with it. Spend some time reading. It's worth it.

Don't ignore the need - immediate or soon - to upgrade the clutch once BB is done.

I searched klx 250 351 kit - nothing - will keep looking I guess

Just search klx351 in the search bar

google something like this?
351 kit site:kawasakiforums.com

I just plugged in "Bill Blue 351" into this feeble search engine. Just the first page had some very informative threads about the specifics of the 351. Yes, some of them have little to do with the questions you listed, but some had great info. You learn something every time you do some research even if it's not narrowly within your original question. It sounds like you're starting your questions about the 351 at the most basic level, so I'd say you'd get a lot out of reading most of them.

If you want the instant, Reader's Digest version, the 351 modification has little if any negative issues...almost all positive. Stock carb works OK with the jet kit you have installed as well as your FMF.

I did all the bolt on mods and was happy for a long time as it seemed like the bike at stage 2 was twice as good as stock and saw no real need for the BB. My bike is an 09 and I did the BB a couple months ago. Different bike completely, my carb is stock just jetted for the mod, my clutch is the original one. Easily pulls the front in 1st and 2nd with the stock gears on power alone and the most noticeable difference is 6th gear as it pulls real hard, no need to downshift to pass just gun it and it goes.

I ride my bike as hard as I can, and I have not found any need to upgrade the clutch at all. There is almost 1000 miles on my 351 with no problems at all.

https://www.kawasakiforums.com/forum...s-links-32538/

https://www.kawasakiforums.com/forum...351-mod-31703/