Kind of what I wondered, if the earlier models were in that state of tune, then backed down.

 

I don't know, but I read the 2021 300 Dual Sport and 300 SuperMoto share the same cams with the 2021 300 R.

 

Did a search on genuine Kawasaki parts and the 2021 dual sport list 12044-0995/0996 for cam p/n. The 300R list 12044-0786/787. The older 300R and 250 dual sport 12044-1327 for the intake and 1487 for the 300r exhaust. 0746 for the 250 dual sport exhaust.
Would be nice to find a cam card for these cam shafts.

 

Something else of interest to me. Looking at an old post the 250 cams had negative overlap at 50 thousands lift. Not surprising from an emissions stand point. I would expect similar for the dual sport 300s.
Valve overlap with the right length exhaust pipe could give a nice midrange boost. My only concern would be the PAIR valve. Does it impact cylinder scavenging? With negative overlap I would think no, but with a tuned scavenging system maybe.

 

One more gimmick in the cam area, there was a difference in the part numbers on the KLX300R cam chain sprockets versus the KLX250 sprockets. There was a a pair on ebay, but I didn't feel like spending the money for them. I think it was like $12. Very likely there was some difference in the cam timing by the hole placement.

 

Considering the PAIR valve is a simple reed valve set up that sucks air into the exhaust whenever there is a vacuum effect in the exhaust port, it will just continue to work as it always has. I didn't remove the pair valve and pollution stuff because I didn't have any plugs, etc when I did the MCM. I figure what the heck, leave it there, only weighs maybe a pound and has no performance effects, so it will continue to burn off unburned fuel mix in the exhaust as it has all along.

Now you are talking about what the MCM is all about. Valve overlap, known as LCA - lobe centerline angle. The MCM increases overlap, which will boost performance. There hasn't been anything written or videos on it for motorcycles, but there have been articles written in Hot Rod magazine and articles and videos online by MotorTrend. They explain it very well and demo the change with dyno runs, using V-8 engines of course, but the result is the same. Here is a link - Camshaft Shootout: Lobe Separation Angle Tested and Explained. They used identical grind cams with only the lobe centerlines being different. Really interesting. Here is another MotorTrend article, Cam Science.

The point to remember is that both the little 250/300 and the small block Chevy are both IC engines and the way they work is essentially the same, just at a smaller level with the KLX. The MCM thread gives the numbers in the first couple posts for the cam timing. I don't know if it gives actual LCA numbers or if they can be figured from the information. Might need more specs on the grind.

Supposedly the MCM doesn't work on the 300/330/351, but with the mechanical facts in the work done, it should have an effect. I don't know that anyone has ever done dyno figures, most of it has been "butt dyno" with riders saying they didn't notice any difference, but that doesn't mean there actually was none. According to the mechanical facts there should be a difference, how noticeable is not known. It reminds me, though, of a comment that Kevin Cameron made in one of his article. During a jetting session which wasn't very successful for the most part, on one of the last runs when his rider (I think it was Cliff Carr) came in Cameron asked his opinion. He said it felt slow, no improvement. The lap time was four tenths faster! The power change made the bike easier to ride fast and thus feeling slow and uninspiring. Perhaps we have the same here. I don't know.

 

Thanks for the additional info. I am thinking of trying the MCM mod.

 

If you do dyno runs it would be interesting. Other test would be to do some roll on runs to see if you show speed gains over a distance. One rider used to do an up hill run to do that. I think he timed them as well.

 

I had not thought to much about testing at this point. I should plan some roll on tests. Maybe just look to do some 4th gear pulls from 3000 rpm to 9000 rpm or something like that. Problem is the weather hear is getting worse by the day, but should get at least another decent day or two before I start tinkering. I have a PCFC and a KDX snorkel waiting for installation, those along with the MCM and gearing is all I am planning to do at this point. Mainly looking for some low to mid range improvement to help with the trail riding.

I got a hot rod I play with and that is easy, I got decent data logging for that plus I go to the drag strip to measure performance. I have done a little bit of looking to see about getting a small stand alone box for data collection. Innovate has a box that I actually use on the car to collect a bunch of extra signals in addition to the data logger I have for the factory ecu. It is just a little big for the KLX and it is not weather proof so it would be only temporary. It also has an SD card add on for collecting the data which is real handy. If anybody has seen something like that specifically for the bikes I would be interested to hear. Something like this would be good for a before and after roll on comparison. I wish the PCFC (version V does I think) had a logging feature.

 

Doing a little searching I came across this Healtech OBD scan tool. It will record data, just would need a small windows based tablet that you could temporarily mount on the bike for logging data. https://www.healtech-electronics.com/products/obd/
Would be handy for maintenance and troubleshooting too.