Hi there, just hoping some one could help me out a little with my 2018 EFI 250.

I have decided to do some performance mods and just have a few questions.



Firstly I am finishing up the MCM mod and would appreciate a “final check” from someone who has completed the mod and can spot errors from a few pic I took of the process. The thing that has me a bit concerned is that the marks on the intake cam sprocket on my bike weren’t exactly level with the case head @TDC to begin. The bike didn’t show any signs of previous work.

I have turned the bike over by hand a few times and no strange noises or binding.



Next I have ordered a PCFC V for a KLX 300. The part number was FC17901, I am hoping this will work by being able to load up maps from Dynojet for the 250 on it. Will this work?



I am still looking for an exhaust and am thinking about just getting a used 300r header and muffler.



Any hints or tips anyone can offer would be greatly appreciated!


After MCM

Before MCM

TDC

 

The 300r header and muffler off the newer ones definitely changed the characteristics of the bike. It likes the rpms now and makes it sound very different

 

Yes I think bang for the buck getting a used 300r header and exhaust combo will be the way to go for me. Would one from 2006 ish fit the 2018 EFI?

With supply shortages these days the price of just a slip on is getting up there.

 

MCM appears to be done correctly - see my PDF below..
Now that hand cranking is done, pull plug and turn over with starter, if ok then start to idle, if ok then rev engine some, if ok then enjoy !

 

Had the guts to start it up today. All good so far.
Some things I noticed. The exhaust note has changed a bit even with the stock part on. Sounds “more raspy” and slightly more “forceful”. The idle has so they out some the engine as a whole sounds better. This could be because I cleaned the injector and reset the cam tensioner while I was in there. Also it may be running a bit hotter, the fan came on while idling after a bit in the garage which I didn’t expect. It is -10c outside right now.
It is becoming full winter here now so I won’t be able to have a riding impression of the mod for some months from now. But I am happy so far.
Any idea of a source for a cheep 300r exhaust?
also do you guys see any issue with using the PCV for a 300 on this 250 to get the fueling correct?
I assume that I will need an O2 sensor delete with the PCV to get the most out of it.
Thanks for looking and the input!
cheers

 

The MCM idle exhaust note is quite different from stock.
You have the benefit of the MCM, MoPowah off idle to 6500-7000 RPM's... Add fuel to the low and mid range for more max MCM goodness.