I got everything buttoned up today. I left the jetting pretty much as it was on the uncorked 250...128 main...DJ needle in the 4th clip from bottom...2.5 turns on the air/fuel screw. I did go up to a 38 on the pilot jet and drilled the starter jet out about .005". Only going up to a stock 300, I figured jetting wouldn't be too different...a good starting place at least.

When I hit the starter button with the choke on, the thing started up in a millisecond. After just about 5 seconds, I turned the choke off, and the bike would take some throttle without complaint. The outside temp was about 68, but this thing has never started that easy or took throttle that quickly.

The other thing I noticed was the pleasant absence of cam chain noise. The motor was as quiet as I've ever heard. I immediately went for a short ride to get the bike up to operating temp. The bike pulled well in all gears very cleanly, so the jetting must be close. There was no pinging or detonation indicating it being too lean and no surging or blubbering from being extra rich. I didn't hammer the bike, but I did go up and down the rpm range at a brisk pace. There was a noticeable improvement in low to mid-range power. I could short shift very easily with total smoothness. It's no rocket ship, but it feels nice and solid. I'll be able to tell more on the dirt.

This was a relatively cheap mod the way I got the 300 kit, so it seems worth it at this point. The cam chain deal is very nice. This is a weird deal with the cam chain on these bikes. My cam sprockets had no real wear, my slider and rub blocks had very little wear, and the crank gear was perfect. I have some acquaintenances in the motorsports area, and I had them look at the cam sprockets and sliding blocks. One of these guys is an absolute expert with many years of motorcycle performance experience at all levels. All of them were positive that sprocket and slider block wear was practically nonexistent. Even the tensioner showed no signs of odd wear or shininess at the adjustment teeth, and they're still nice and sharp. It makes one think that the spring may not be up to par or such. As someone here suggested...I think it was here on this forum...when you put the crank on TDC at the proper cam angle, the marks on the cam sprockets should be parallel to the head casting...just like in the pic in the manual. Before the cam chain replacement, mine weren't. Now they're dead on the money.

Anyway, I'll get some more break-in miles and make sure the jetting is sorted out. It feels quite nice at this point. It may not be a BB351 kit, but I can already tell it's an improvement. And the cam chain quietness alone is nice. I'm going to keep a close eye on the tensioner. I'm going to keep thinking of a manual mod.

 

Imagine that, the same thing I saw on my second KLX tensioner when we tore down the top end to replace the chains. I made the tensioner manual. Then my Zephyr made noise like a hornet's nest, so I made four extra when I made one for it. That was a year ago and about 60 tensioners later... I sell them for $30. I already PMed you with more detail.

I make tensioners for a bunch of different model Kawasakis and the DRz400 and have done some custom work too.

Feel free to email me or look up Krieger Cam Chain Tensioners with a google search. The site isn't quite finished, but it has some detail.

I don't make a living with the tensioner business, I'm a middle school industrial tech teacher with an engineering background before teaching. I've been 40+ years in motorcycles and 22 years of full and part time sales. I just enjoy the bikes and the challenge.

Presently I've sold tensioners in 22 states, Canada, England Scotland, Finland, Netherlands, Latvia, Malaysia, Singapore, Australia, and New Zealand. I have yet to have one negative comment or return request.

I'd enjoy helping anyone I can with tensioner issues if I can. Look me up.

 

I googled it. Looks like a good way to go. I don't see the KLX250s or KLX 300 listed. I imagine it would fit though.
http://www.kriegercamchaintensioners.com/
Dan

 

That's why I want to do one. I forgot to mention the 40mm hole spread on the most common Kawasaki tensioner body. If it's that size I'm good to go. I also have a smaller one I have made for the KXF450, a relative has one of them. It is smaller in hole spread and general size. If you see anyone needs to do something with a tensioner hook them up with me. I WANT to do one of them. That's how I've done a number of them I now carry, like the DRz400, the RMz450, and the square body tensioners, some help from customers to make a custom prototype. When I do that I guarantee it will fit and work or all money back, including shipping.

 

Looks like the KLX250/300 uses something in the 33mm range on the bolt spread...at least as near as I could measure with my exhaust in place.