Working on making my 2021 klx 300 more fun on the trails,, without losing too much on road. Just put on delcavic exhaust, back firing on hard downshift now, gonna throw in a kdx snorkel to balance intake. Is the kdx snorkel the beat way to go?

 

If it is exhaust crackle versus big backfires, that's normal due to the lean condition when the throttle is shut. But with the work you are doing you may want to reflash or do some other device to richen the mix.

 

thanks. Yes, it is having trouble compensating the change of easy outflow while restricted intake. On downshifts it's popping hard,, needs more air intake to balance,, and the only other snorkels I've seen are for kdx. Hoping to install new snorkel and filter, then remapping. Looking for advice from anyone that may have done this on efi klx250 or klx300 to eliminate some of the error from my trials.

 

Also looking for remap as well as dropping a tooth in front sprocket. Anyone done this?

 

While my KLX300 didn't pop much with a completely stock intake and a full aftermarket exhaust...



I removed all of the smog equipment




and blocked off the pair valve...



...and there is absolutely NO popping whatsoever, even with no fuel tuner or reflashing.

 

Ok. Got the kdx snorkel in. Huge improvement. Air flow definitely better balanced now. No back fires,, just strong gurgle on down shifts. Ready to remap and waiting for 13t front sprocket. Anyone done this on efi klx? Looking at power commander but would need some help with any tunes people have found that will save me some time.

 

We're on the same track...
I also installed a snorkel.



It appears to have about double the cross sectional area from the stock one.



I didn't notice any difference under 50 mph (3,000 to 5,000 rpm), which is about 90% of my riding as I just use my bike for daily road transportation. I'm sure it will make a difference at higher rpms.

There is zero popping even with no tuner. They're still out of stock, so it'll be a while before I get one.

 

What do you mean by blocked off pair valve. Can you explain to me what it is and what it does? Is it an 02 sensor delete?

 

I keep my bike in the happy 5k-7k rpm typically, even at lower speeds, and I definitely feel a difference. Feels snappier, and pulls harder especially though top end of PowerBand

 

No. The O2 sensor is attached to the exhaust midpipe near the muffler. It adjusts fuel mixture during partial throttle operation. I did not delete it. The pair valve is on the front of the engine. It injects air into the exhaust for emissions control. I deleted all of the smog equipment. That SmartMoto plate in the picture is on the front of the engine cylinder. That's where the pair valve used to be.