Well I do have a neighbor I'd like to blow off the porch with loud pipes but that is another story lol! But yes looking for a nice sound and appearance when it comes to exhaust! As I heard someone say "get rid of the sewing machine sound"!

As for the MCM, should this be done with just the 250 to get more out of it? What about with a Big Bore kit! Can they be done together? Is there a difference of adjustment w a big bore! Is the big bore even worth it since im learning the computer and FI set up restricts so much!

For starters Id just like to do the lidless exhaust EJK mod I guess! I need to learn more before doing more down the road!

 

If I ran the EJK, went lidless, and did the MCM *but* kept the stock exhaust, would the gain still be a substantial hit over stock? If I get a slip-on I want an FMF, but they're out of stock and having a hard time keeping up with demand due to the pandemic. I don't know when I'd be able to get one. So if I get just the EJK for now is it even worth spending the money on it yet?

I want a very noticeable gain in power, not something that's subtle where it might just be a placebo effect in my head and I'm not really sure that it did anything. I wanna at least be able to get the front wheel off the ground in first gear on the trail to get over logs and such.

 

Well for you "new guys" that don't "know me" yet, lets a few things crystal clear :
1. I never, ever, speak even one word, based on some kind of ideology or belief system. The only "belief system" I have is to disseminate information that is the factual best info for the members' needs/questions.
2. My posts are based on provable facts and knowledge, gained from years of data that has been accumulated, both personally and in here. All of which is independently provable/verifiable.
3. In the rare instances where I must resort to opinion to address an unusual problem/situation, such will be always be prefaced by "IMO". And such "IMO" will be based on non-subjective data applied via deductive reasoning ( a highly educated guess )..

So.. Federal laws ? LOL... F%*k NO, NEVER ! ..... And such inferences are offensive to me.

Only AFTER you are fully versed on the basics of EFI fueling (closed loop and open loop fueling control) would you be able to understand the reason you MUST have a bung in your midpipe - But for now, it is so you will always be able to run your O2 sensor ( and to be able to safely experiment with NOT running it.)

Except for the Q4 and a full KLX300R system with performance endcap, ALL aftermarket slipons are LOUD ! While there are subtle differences, LOUD is the the thing that all of them have in common. ( The PC4 is "mo quiet" than a DGR - from personal experience with both..)

Your path to best performance will end (with amazing results) when you are running the following mod combo:
1. Performance slipon (with bung) and the stock header.
2. MCM done properly and completely - no bullsh%t corner-cutting crap ( doing only the intake or only the exhaust cam)..
3. Lidless airbox with a lightly oiled air filter.
4. EJK installed as per its' instructions and configured for lidless running.

 

1. Until you get a performance slipon (with bung), there is no need to buy/install an EJK.
2. The MCM (done by-the-book/correctly) ALWAYS creates a noticeable (and proven, and verifiable) power increase from off idle to near 7000 rpm. This will happen REGARDLESS of all other factors (performance mods or no mods at all..) IN FACT, from personal experience, the MCM should be the first mod done to a stock bike ! It was the first mod I did to my dead stock bike - and the dynobutt results were so impressive that I embarked down the road to creating a max performance, dyno created/verified, set of mod combos. Such also eventually allowed the creation of the dyno data that proves MCM gains and effectiveness over stock cam timings.

 

So just going lidless and EJK by itself without a pipe doesn't gain any power? I would have figured that improving the fueling and getting rid of the airbox restriction still would have helped somewhat without the exhaust.

 

No, in fact, while using the stock exhaust system, there will likely be a loss of low end power and throttle response by going lidless with EJK.

Here is a tidbit that you won't understand - but if you ever reach the point where you do, you'll look back here and think "yep" - There is very few ways to successfully detune a SOHC, high compression, engine, so that it functions well, while exhausting thru a soda straw. The easiest way is to match flow characteristics: the induction system and the exhaust system. This is what Kawi did. They did NOT detune the engine thru "mechanical"/design means ( tiny: valves, cams, ports, etc) ,.. This is why a relatively simple "uncorking" takes the engine to vastly higher power levels..

 

How would going lidless and tuning the fueling decrease throttle response and low-end power? If we were altering the length of the intake runner for example then yes I would agree, but removing the airbox lid?

 

The tiny snorkel promotes a high velocity airflow thru the induction system - aiding in low rpm throttle response and low rpm trq production. This matches well to the stock exhaust system - which does not allow high rpm power production due to its' restrictiveness. The induction system is "tuned" to provide as much riding enjoyment as possible given the restrictive exhaust system..

 

I don't buy it. You have the snorkel, then a huge gap to the throttle body occupied by a large open airbox with a huge filter. Velocity at the snorkel is not being maintained through that huge distance through the thick filter and box, through the throttle plate and into the cylinder. We're not talking about a GSX-R with ram-air here. You're not getting higher cylinder pressure from a smaller opening on our bikes.

Also in regards to Kawasaki tuning this bike for as much riding enjoyment as possible... Please. If that were true and they took that much care with this bike then there would be no need to perform the MCM. We're talking about an engine that comes from the factory with cam timing for the wrong RPM range here, so don't automatically trust that the snorkel is a prime piece of engineering.

 

I've composed a response several times now.. My laptop erases it before I can finish... Perhaps this is a sign - so I will simply ask: Do you need me to respond with an synopsis of induction system pressure gradients .. and more about the obvious dichotomy of the "as delivered" configuration of the KLX250 engine...?