Thought I would post some thoughts and observations to get some discussion going around the new 300s

I don’t have any delusion about what the KLX300 dual sport (DS) is or can be, but I want to get any power that can reasonably be achieved. For this upcoming year, since the bike is new, the most I am going to do is a KDX snorkel (already swamped the bike once, so taking the lid off the airbox is out of the question), maybe a slip on, and a PCFC (already have). Have not decided how I am going to tune the fuel yet (dyno or get a wideband). No minor/major disassembly, going to ride the **** out of it on the trials with my kid on his KLX230 for this upcoming year. So, with that out of the way, here are some of my observations.

While the Kawasaki promos say it shares the same cams as the 300R, that is not true. The 300R has the same cams as the Z250SL Asian/Euro mini sport bike (maybe the lobe profile is similar to the 300DS?). It appears to have a beefier cam sprocket flange and the two bikes share cam sprockets. As best I can tell they are only used on those two bikes. No KACR. The 300R also has a different P/N for the head, piston, cylinder. So, I assume some machining difference, no idea if it is to accommodate the different cam or what.
I dug up some dyno charts and rough plotted them in excel to see the difference between the 300DS and the 300R. These are not decimal place accuracy, it is something I did for myself to do a qualitative look at the power characteristics between the two bikes. You can google search all these charts or look in the forum here and find the dirt rider and tooter charts. I think the 300R charts came off of thumpertalk. The charts I compared are:

Dirt Rider stock 300DS
300SM posted by Tooter with exhaust only upgrade.
Stock 300R
Stock 300R with Power Commander V (PCV) tune – Fuel and Ignition (wish they made one for the dual sport)




The 300R has a nice amount of torque over the 300DS right where you want it for trail riding. Also, I can’t confirm this obviously it is an internet info, fuel and timing adjustments alone stretch the top end on the 300R a good bit as shown by the chart. I wish the DS had the same curve.

My guesses are that the 300R cam timing and ignition curve is what is giving that better torque curve. More valve overlap will help midrange and that is my guess of what the difference is. 300R has same valves and valve components and same head port limits as the dual sport. The head design sucks for high end horsepower and from what I have read on the forum the big bore kits have shown that. Both bikes sign off with similar power up top. Add an airbox mod and good exhaust with the PCV to the 300R, and that seems like it would make for a really nice trail bike.

Again guessing, but the DS is probably tuned for emissions, which minimizing overlap and possibly pulling timing to limit unburned fuel and lower combustion temps in the required operating range for the EPA may be what is going on. Maybe it is something else.

It is kind of hard looking at the 300R power and thinking back to the off road riding I did last summer and knowing that is where I want the power. I am not going to try anything like the MCM this year, but I am thinking longer term like maybe next winter. Also, I wonder if the 300R cams drop in or if Kawasaki does something different to the 300R head.

If anyone has additional information on the new 300s let’s start collecting it. Any other interesting info please add.

 

This is the dyno test for my bone stock 300SM with only an exhaust and no tuner.
Peak horsepower is at higher rpms than stock while peak torque is at lower rpms than stock.

25 HP @ 9,160 RPM

16.5TQ @ 7,660 RPM

 

This spring/summer will not not be digging into the motor, but next winter I may be looking to tweak it. I would really like the 300R curve for off road riding. Between 5k to 8k rpm is where I would like the meat!

 

FYI guys, the only way those aberrant power curves can be created is thru ECU programming ( fueling, butterfly valve manipulation, ignition) .. Another way of saying this is to point out that Kawasaki has purposely muzzled the DS engine through ECU programming.

The needed solution would be to "port over" the 300R ECU ( or other "offroad only" and "DJ supported" ecu.) to the 300DS by whatever means are necessary..

 

I think there is a little more going on than the ecu to get the curve, but I agree that the ecu through the ignition curve may be part of the issue. Without seeing a cam card for each bike, I am leaving open the possibility of valve timing also as part of the difference.

I am still trying to learn the various bikes and how they work, but it appears that the 300R uses an inductive ignition where the 300DS uses a CDI. I don’t know the subtleties of exactly how the ecu triggers the spark in each case, but the CDI fires an igniter and rapidly charges the primary coil using a capacitor to generate the spark where the inductive ignition simply grounds the primary side to collapse the already charged coil to generate the spark in the secondary coil.

Swapping ECUs could get expensive real quick. A stand alone cdi for the 300DS may be an answer, not sure how hard or easy that may be or how easy one would be to tune the ignition. Also, to the point of the throttle valve, I wonder if the 300R uses a different throttle body?

I plan to just poke at this stuff over time mainly for fun and entertainment.

 

From the"dip" in my dyno chart, my guess is the secondary throtttle plate may be responsible. Watching its operation closely while revving the engine, it's electronically controlled by the ECU and operates completely independently of the mechanical primary butterfly. I think it may simulate the operation of a constant velocity carburetor.

So my question is:

Does the KLX300R ALSO have that electronically controlled secondary butterfly?

My stock gas tank had a gaggle of three emissions hoses coming out of the bottom while the new one has NONE so it's really easy to remove and install. I'm going to take off the secondary butterfly to see if I can feel any difference.

 

Klxster or anybody else have more info on the secondary butterfly. I was not familiar with that. God I hope that is not the issue.

 

It is much worse than you think.

ECM controlled throttle modulation with Ignition and fueling programming to properly fuel the programmed throttle modulation.

You can snap-and-hold WOT on your throttle grip all you want - but what you get is the programmed throttle modulation with ignition and fueling to match.

Anyone that understands the nuances of the emissions' testing regime that must be passed, the reason for "double hump" trq curves becomes obvious.

If the ECM is ever "cracked", the entire programming would have to be revamped -
1) Throttle butterfly valve(s) modulation reset to strictly mirror throttle grip input at all times.
2) Entire revamp of ignition and fueling programming to properly operate the new throttle scheme.

Better to explore "porting over" an offroad ECM - or at least an ECM that has complete re-programming available thru DJ products.

 

If a PCV made for a similar ECM is found to work on the 300DS, it may be possible to end up with a "proper" power curve @ WOT. Hand drawing a curve from one trq peak to the next would be approximately the expected result.

 

The 300R does not have the sub-throttle.
Looking at the parts break down online it appears to use just the main throttle butterfly and an idle air control motor.
So, for whatever else that sub throttle does, I am guessing it is also used to control idle speed on the 300DS.
I have tried to use a standard OBD scan tool on the 300 and it will not read the ECU, so Kawasaki on the 300 anyways does not use a standard OBD US or Euro diagnostic setup. Some bikes do.
Healtech has diagnostic software that will read the 300, problem is it is windows based only so you need a small windows tablet if you wanted to drive around and log data or use it on a dyno. It would give the sub throttle position vs all of the other ECU parameters so you would know right away what is doing and would be able to see if it was only part open at the dip in torque or full open.
Dynojet offers a PCV for the Euro KLX250 but I don’t think it does ignition timing. The online information is vague. Other bikes like the KLX230 and 300R have a PCV that does fuel and ignition but use inductive ignition and I have no idea how to adapt that to CDI or if it is even possible with my knowledge of electricity and electronics. I am guessing that the PCV reads the ECU ignition trigger event and modifies it by opening the ground to the coil at the next event and advancing or retarding the number of degrees set in that cell in the map programmed to the PCV. I doubt calling dynojet would be any help as they are not likely to tell you how it works so that you would be able to adapt one of those to another bike.