Well I had my ebay bid in on a 2002 KLX300 cylinder about a month ago. I was out bid by someone in the UK, but they didn't pay. Seller sent me a "Buy It Now" option this past Friday that expired Saturday. I didn't see the message in time but checked MY Ebay Favorite Searches this morning and guess what? KLX300 cylinder up for auction. Starting bid $10.49. I decided to click on "Ask Seller a Question". Question being, "how much to buy it now and be done with it". I just bought a 2002 KlX300R cylinder for $125.00 including free shipping. My plan is to go straight to the 330cc big bore through www.kustom-kraft.com, about $400.00 including Nickosil cylinder wall lining. I am considering hot cams while I am doing the top end. Any ideas here? Current mods include carb w/ N1TC needle, clip @ #2, stock main and pilot, mixture screw @ 1-1/2 (7800 ft. and usually up from there; 90% offroad), bike runs/starts great and plug is light chocalate in color. Smog stuff gone and crankcase vent enlarged to 1/2". Dual snorkel set up W/ Uni filter. Big Gun full system exhaust w/ the quiet core. And my much appreciated full coverage wrap skid plate from Utah Sport Cycle. Those of you that have been down this road before are more than welcome to give much needed advice!
Also of concern, will the stock carb be adequate for the increased displacement? I am pretty sure I will at least need to increase fuel delivery throughout the low, mid and high range. Anyone know if the KLX250S and KLX300R carbs are the same? They both spec to be Keihin CVK34.
I planned on buying this little Dual Sport and just riding and enjoying it. But I am an old moto-crosser and the need for more just keeps coming up. Not to mention a few influences here and there. LOL.

 

When I did mine I had a 125 main jet, #35 pilot, N1TC needle on 2nd clip, fuel screw at 2.5 turns out. When I went to 331cc, I bumped up the main to 130 (or was it 132?), kept the pilot at 35, move the clip to the 3rd position, and set to fuel screw to 2 turns out. I also have the dual snorkel setup. It ran very well with that setup but I'm near sea level, so I don't know if those settings will translate directly for you.

The CVK carb will work fine with the 331cc, but you are on the right track and that is to get it jetted and dialed in correctly for it. With mine, I got a good strong mid-range pull that was just great. But it wasn't until I went with the Keihin FCR that I really saw that instant response that pops the front end up with a throttle blip. You will still be very happy even so, the 331cc adds some serious grunt and you'll definitely be writing home about it.

Careful with the cam chain though during install. Late in the install after getting it all back together to the point where I was re-timing the cams, I noticed that I had somehow managed to drop the cam chain off the lower sprocket and had to take it to the shop to get it back on as I didn't have the gaskets for the right side engine cover. I was more embarassed than anything, though. But they didn't laugh at me, at least not to my face and had it back on for me the next day - less than 24 hour turn-around for a busy shop, I felt like royalty or something.

 

Nobrakes,
Yeah, the pumper is probably the next Mod that I will install. Not for a while though; so I will have the forum knowledge to go on. I am liking what I am seeing with the Yoshimura TMR-MJN34 that tremor is installing.
The ease of jetting for altitude and all around performance is also a concern.
Oh, good call.....GASKETS. I saw a complete set of top end for $31.00 on ebay. Do you think I should go ahead and order that right side gasket.

 

Just don't drop the chain and you won't need the R/H gaskets, tie it to the frame or something maybe a skyhook [8D]

 

Easy for you to say!

 

Yeah it is isn't it lol ... I'll find out in a month or so when I do mine [8D]

 

I reckon I'm 50/50 in that department. I've done two big bore installed and dropped the chain once. My advice is to just be prepared to handle the situation should it happen. Digging into the right side cover to get at the timing chain doesn't look too bad, just have a spare set of gaskets on hand. Even though I didn't have gaskets and had to take it to the dealer to reinstall the timing chaing, I'm still way ahead overall since I didn't have to pay any labor for the first install, and the bill for putting the timing chain back on for the 2nd install was a lot less than the quoted labor price for doing the whole job. Even so, live and learn - chalk it up to experience. I'm smarter now.

 

Why is it that we can hear things from other folks about this, that or the other, but when we do it for ourselves that you learn so much.


I think knowledge is a great thing, but the application of that knowledge is where the wisdom part comes in.

 

Hey Nobrakes,
Thanks for that carb info. I found out that the same guy I got my KLX 300R cylinder from also had the carb and offered it to me for $40.00. The Kawasaki specs show both to be the CVK34mm but our local dealer says that his books show that they are different. Anyway, for $40.00 I just went ahead and got another carb - KLX300R, and I will see what the differences are. Did you use Kustom-Kraft in Glenwood Springs, CO for your big bore? Thanks again for the input.

 

Yep, that's who did mine. Everything went as planned with them, no excitement to report - I shipped my cyl off to them and they shipped it back when they said they would and with a few more goodies in the box to finish the job. And so far so good, it hasn't self destructed or anything. It runs very smooth, I'd do that mod again in a heartbeat.