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Hi KLX er
Did some research. As known the KLX engine gets used for Kawasaki Ninja 250 SL too. So I looked to repair manual for futher details.
Cam timing for the SL at inlet cam is differnt, and a 38 mm efi housing is used, power is 28PS at higher revs as at the KLX. Service interval same as for KLX - 12000km oil change and valve clearance check.
Also gearing ratio is different- could be intersting for overdrive 6th gear on the KLX .
I thought this is maybe intersting for some of you.
When comparing power from the 90´s KLX with the ones from today, I can not see a different cam timing- "only" ignition timing is different.
Wouldn´t it be the easierst way to gain power by changing the ignition timing and of course the EFI fuel control. may loose some durability- look service intervalls for the 90´s D models.
If so, I save alot of money and wrenching
The cam timing modification done by Marcelino costs $0 if you do it yourself. If you pay someone it will have some cost depending on how much work they have to do, but still likely to be lower than the cost of any ECU work. Of course a lot of us have carburetors since it can be done on all KLX250s from2006 up for sure. I think the better question would be what would happen to that Ninja single if the MCM was done on it considering it has a bigger injector body and the different ECU settings. If the new bike has the old cam timing settings the cam timing change would increase mid to upper range horsepower. It is pretty well a proven thing in four stroke engines, car engines have the same changes with similar cam timing changes. click here for information
I agree MCM is for free as long as you do your self. But this is not my "for free problem". MCM gives you more torque at lower revs, which is good.
But it didn´t give the +30 PS like on 90´s D model.
I mean before I go with big bore, FMF or similar, snorkel , EJK and all of this, using an ECU with different iginition and FI ... (like API from thailand?) and adjust this "new" ECU...
That´s what I mean to save money.. no big bore and this things..
Big bore need also new ECU setting...?
Any expertise about that.
BTW: i know how a 4 stroke work but not in that detail, what cam timing has what influence.. I´m more on 2 strokes where the port opening and closing is essential for the wanted engine perfomance.. and of course the ignition timing.
Thank you KLX678
@lb-rider that's why I included that link. If you read it you will learn an interesting misunderstanding about the MCM with the increased overlap, that most rider have. It does not increase low end as most think, rather it increases mid to upper range power. The thing is the loss at what is an extremely low rpm for the 250 single and is in a range that is nearly unused by KLX riders. The loss is down in the 1000-2500 rpm range, while the power increase is from around 2500 rpm and up. One other thing, the power boost does not come at the expense of having to rev higher rpm. The HP peak is still around 8600 rpm and virtually no one runs around on their KLX250 in the 2000 rpm range except for puttering around. Any sort of serious riding will be in the 4000-8000 rpm range, like riding on freeways. Car engines do use that low rpm with most being in that low range quite frequently.
All of that shows in the article and is pretty much true with all four strokes. I learned more in that article which I read in the magazine having a Hot Rod magazine subscription. I was glad to find it online so others could understand what was going on. One reason I still subscribe to Hot Rod magazine. Used to be in the 60s-80s the magazines used to do actual hop up articles, not just ones where they have everything bolted on by a shop. In the 70s I did forward mounted shocks on my MX bike based on articles on it. I did my SR500 hop ups based on a 1979 magazine article by Gordon Jennings. Now the U.S. media is pretty much crap, no tech stuff.
If you should ever have your valves checked you could easily have the timing altered. It's just moving the cams to the specified sprocket location and disabling the compression release (which isn't needed anyway).
Did you go ahead and do the cam mod? Was it necessary to reomove the cams? It occurred to me as well is you didn't plan or dealing with the ACR, all you should have to do is set timing marks on crank, remove cam chain tensioner, rotate the sprockets, then readjust cam positon and button it back up.
Hi there, does this mod works with the EFI klxs? Is there any recent walkthrough of the procedure because the photos of the original post are not visible?
What about top speed? Is it same, worse? Does it needs ejk?
Last edited by cycloholic; 05-15-2023 at 08:23 AM.
The original was done on a European EFI KLX. Top speed will likely remain the same since the peak horsepower is around the same rpm. To go faster it will either require a lower gear ratio or cams to pull more rpm. I have a write up on the MCM in my signature.
The only damage would be if you didn't set the timing correctly. The engine piston must be at Top Dead Center compression to do the work. KNOW what you are doing. If you make a mistake it is possible to bend valves and possibly damage the head, big money. If you are relatively new with working on bikes GET HELP. It is easy to screw up if you aren't careful. It requires removing the cams and putting them back in correctly timed. Errors here will damage an engine. I cannot warn you enough, if you aren't adequately experienced either get help or do not do the timing change.
The KACR must be disabled by removing the spring, otherwise it will be opening at the wrong time and will make starting near impossible. The original post or one shortly there after tells how to have the release mechanism pressed out and reset to work with the timing change. Fact is the bike spins over and starts fine without the compression release. I've been running around 10 years without the release working. I didn't remove it because I didn't have a way to press it out.
06-21-2022, 07:29 AM
