Klxster, I'm not trying to cast aspersions on anyone. I'm just cautious. I would have liked to see a "before" dyno curve as well as all the "after" ones from Marcelino. Maybe the dyno he used was way optimistic or the scaling was wrong or something?

I don't have easy access to a dyno so if I do the mods, half or full, then the results will be have to be anecdotal (like zippets - which I appreciate).

FWIW I have just tried my completely standard (except clutch switch shorted) 2012 EFI without the airbox lid. I got 87 and 81 MPH indicated (both ways, same road) without the lid and 86/80 with the lid. Prevous experiments using GPS show my speedo is 10% optimistic.
I don't like the noise without the lid and I got the impression that low end response was actually slightly worse without the lid, however this could have been the (inverse) psychological effect of the noise.

 

Ok, gotcha... Your EFI stands to gain the full horsepower and torque increase from the mod. There is not ANY post showing ANY damage from this mod on this 2 year old thread. You can put your fears to rest and trust the information and those of us that report the results. Hope you saw my video.. However, this mod - even just on the intake cam - is not for an ungifted or reckless mechanic. Cautiousness is good, lack of confidence or skill could trash your engine.
The mod works - your bike (EFI) stands to gain the most - The question is, can you pull it off.

 

I've got some mates who can pull it off:

http://www.beardmorebros.co.uk/index.html

 

Yep, probably someone there can do it.. England huh,,, I've vacationed there... You may need your KLX and/or rely on it every day. If so, I advise you to leave it alone. Being a typical Texan, mine is only one of about half a dozen bikes in my little "collection" and would not be missed if something went horribly wrong - I had very little at risk.

 

You will definitely need to unplug your 02 sensor & replace it with a 02 sensor eliminator (simulator). This will trick your ecu into running at max richness, it will not make as much of a boost as using a PCv or a EJK controller but will really help richen things up after removing the airbox lid & doing the cam mod.

Jeffward made his own 02 eliminator from DIY shop bought resistors & his thread is a good read for a new EFi owner:
https://www.kawasakiforums.com/forum...250-efi-35678/

 

No my KLX is just a toy. I might swap it in the spring for a toy that suits my riding style more: KTM Freeride. Only 23HP, but I suspect it'll have no problem popping the front wheel up. I just wish KTM would ditch the horrible lawnmower-orange colour!

 

Greetings to all!
There are many comments in this post!
First remark that the evidence in the dyno were measured to the clutch, so the figures are slightly higher than those obtained at the wheel. That is why they can not be directly comparable.

-The complete change in the 250EFI Marcelino must obtain figures of about 23/24 hp at the wheel.
-Increases torque in the usable range, which is the best we have.
'The worst is that you lose some speed in the upper engine turning.
-Some owners of this motorcycle in Spain, that use the bike exclusively by asphalt, perform only the modification in admission, to obtain a little more of torque, without losing stretched when motor. The benefit is not so great, but compensates.
-For off-road if necessary and beneficial see complete modification.

With respect to 300cc:
Personally I did many tests with cams on my bike. Camshafts even bought a 300cc engine and found that they are different: the opening of the valves is more pronounced and narrow. The EFI opens the valves for longer and with less height.
That's why I do not get the same benefits with motorcycles prior to 2009, as the cams are different.

For increased engine displacement got the best results by changing the intake cam only. In this way the engine kept stretched and had a good torque.
I also changed only the exhaust camshaft, and the results did not convince me. I tried it with the original cams and 300cc center. In both cases finally convinced me. The bike runs but I noticed something abrupt and lost efficiency.

As for the elimination or snorkeling, the noise that removing it is unbearable. Replacing one of KDX200 is one solution, but also by modifying the noise decreases Marcellin. Similarly decreases the more open is the exhaust system.
On my bike I've been snorkeling modified with a platform designed for me to host the PowerCommander. I left the air inlet large enough so that the noise does not bother me.

 

I am sorry but... Damn! You can make things as complicated or as easy as you want. I've done the mod 20,000 km ago (maybe more, maybe less) and never looked back. What I did was:

1.Understand the mod: Just read the first post. Everything you need to know to do the mod is there.
2.Quit discussing about the mod: You really don't know what the guy next door did to his bike. Don't rely on everything you read/hear on the net.
3.Do the mod and see if anything improves: Only way to find out if it works for you or not is to do it. Someone halfway around the world really won´t be able to tell you that.
4.Enjoy: I know I do.

 

Just read the whole thread twice, wanted to make sure of a couple points before I go through with it. Note that I currently have a stock 2012, and will be adding a DG slip-on and removing the airbox lid at the same time. + jetting of course.


1. Doing only the intake side is a viable alternative, and gives some power increase but not full potential, correct?

2. I understand the ACR mod, but have not seen a good how-to pictorial. I'm not positive if I would try it myself or take it to a shop. Either way I'd like to be able to show the shop exactly what needs done rather than them blindly figure it out. I've lost faith in repair shops over the years.

Am I correct in thinking that the cam itself is hollow, and the ACR is acting like a 'cap' on the end? So basically secure the cam then push the ACR out from the inside, then turn and press the whole assembly back together? That seems easy enough. It also sounds like any good machine shop should be able to do the work, or even be a 'home brew' solution with a few different options.

Kansas-klx talks about a homebrew method using a bolt, chunk of metal, and grease. Seems like it would work, as it did for him. How is it going back on? I'm picturing just throwing the entire assembly in a press and the ACR just sliding back into place. Not sure how much pressure is needed, as I have a homemade press type jig that uses a bottle jack. It's crude but has gotten the job done before.

3. As much as I don't want to admit it a big bore kit might be in my future. Not sure when though. Would it be logical for me to do the intake side only, then if and when I do the BB kit just put everything back? Would save on ACR work X2 at least, as the cam mod doesn't seem to help once you go big bore. Perhaps the ACR work is easier than I'm picturing though. Mainly I haven't seen any talk of just how tight it is on there.


Thanks for any help.

 

Jules, You are correct in your thoughts about the intake cam only. I have, basically, a machine shop equipped well enough to allow me to build a collar to support the cam in a correct and safe manner.
I also port matched the header opening to the exhaust port. Easy to do if you have a die grinder or a lot of time and a good dremel. If you do this, do not grind all the way through the weld or you'll ruin your header.
I assume you've read all my previous posts - Yesterday I installed the #132 main jet from the kit. This was because the Dyno pull indicated a lean A/F curve. The bike pulls even harder now. I guess I'll pay for another Dyno pull tomorrow to verify my seat-of-the-pants impression.