My quest to get a modern 250cc motorcycle to deliver the power I know its capable of never ends.

2018 KLX250 with the following mods.
FMF q4 muffler with powercore insert
KDX snorkel
twin air filter
Marcellino cam mod
Secondary throttle plate removed
EJK fuel controller. Grenn:2 yellow:3 Red: 2.5

Top end felt good, but bottom end still felt gutless despite the different combinations of setting tried on the EJK. So, I installed the SAFR to get an idea of whats going on.

Idle~15:1
3k cruise: 15.5:1
3k WOT: 12:1
4k cruise: 12:1
4k WOT: 11:1
5-5.5K cruise 11:1
5-5.5k WOT 10:1
6.5K on up at cruise and WOT is around 12.5:1 so pretty good there

I have plans to acquire a 308 BB kit. I will also probably undo the cam mod. This thing really needs a custom map. Even though its stronger overall with all these mods, I still feel the same tendencies as I did when it was stock (IE 3k is strong but 5K falls on its face). Unfortunately it seems that power commander doesn't like USA. Unable to acquire FC17900E.

More to come.
http://www.dobeckperformance.com/dobeck-SAFR-tool.asp

 

Undid the MCM today with no other changes. Bottom end throttle response is much better. WOT from 3k to 9k stays fairly steady at 12.5:1 to 13:1 . Cruising at 5k and up is a little rich at 12.5:1. Cruise at 3k-4k is at 15:1 . 2k in first gear is so lean it isn't even on the scale. Fuel tuner setting was at 1 for all ranges. It also felt a little more willing to go to 9k. Biggest improvement was 4k-5-k when snapping on the throttle. Instead of "I'll go when I feel like it" it's " LETS GO!!
I'm diggin this bike now. I can get the front end up with a little bounce without clutching it. Looks like MCM is a no go for us EFI guys until a custom fuel map is developed.

 

great info.

did you remove KACR ?

Wont change performance, just curious

 

I removed the KACR spring the first time I did MCM. Disabling KACR and blocking the pair valve fixed the wandering idle issue. When I undid the MCM last week I pressed the entire KACR mechanism out.

 

Good info!

What does removing the Secondary throttle plate do for the bike. How easy is it to do?

Toph

 

Warning explicit language.
It's useful for low end power when you have an engine mainly tuned for peak power, such as the supersports that rev to 16K plus.
My ninja 400 revs to about 11K and makes excellent power low and high, flat torque curve, and it doesn't have STP's. Just a well designed airbox. So it has me scratching my head why they put a STP in the KLX 250. Heck, all they would have to do to make the KLX250 a TBW is add a sensor to the throttle and reprogram the ECU.
It's been awhile since I did it but heres the gist. Remove tube from airbox to throttle body. I bieleve the screw is a #1 phillips. Use a high quality bit dabbed in valve grinding compound or screw grab, and a 90 degree bit holder. Do not drop screw into engine.

I have a klx 300 exhaust coming and a wiseco 80mm piston. Once all thats sorted the last thing Ill probably do is reinstall the STP to see how much of a difference it makes. When I took off the STP I didn't really notice a difference, but I was so focused on peak power that I could have missed a difference at the bottom of the rev range.