yz250fx throttle chop fix?

Hey fellas.

I've just bought a secondhand yz250fx, and so far I love the bike, except for one thing.. The throttle chop, when you let off the throttle, it's really just stops,it makes it really hard to ride smooth in single track, is there anyone doing a simple remap for the bike the have the throttle chop be more progressive and smoother?

up the idle speed

Gytr tuner you can change the map and fix it

Try the GYTR soft/slippery MAP and go from there.

I found it really mutes the throttle input in general. Feels like you have to twist it farther to open her up on wider hill climbs, but it was really smooth modulation for single track.

 

I was testing 250FX MAP settings on a little 10 minute trail loop yesterday. I would record max RPM (hill climb) as well as notes in performance after each change.

Funny that after the GYTR soft MAP I noted it as smooth and mellow, then checked max RPM and it was over 11k where the previous 3 MAPs I tried were all just over 10k!

It felt smoother, and slower, but I don't think it was!

 

Yamaha tuner and a hour meter that records max RPM make testing super easy and fun. I have a setting that makes this thing feel like a 2 stroke!

It felt to me like the soft map increased engine braking. But it is worth trying a few different maps.

 

Idle speed should be at least 1900 rpm I think. Don't have the manual in front of me.

Edited by ubu

Idle speed 1900-2100, I go right in the middle.

I thought the same thing when I first got my 14 YZF, turned the idle speed up at the end of the first single track and never thought about it again.

Engine braking was the most difficult thing for me to get used to but I finally got the hang of it. I've always been a 2 stoke kind of guy and never liked the 4 strokes. However, I have become vey fond of the FX once I finally got used to it. You may just want to ride it and give it a little time. Good luck

I hate enginebraking in general, with my old bikes i'd set the idle high deliberatly to minimize it, but with this, it seems if you set the idle higher, it doesnt reduce the enginebraking at all, the EFI just doesnt allow the revs to drop as well, but while riding it still feels light swtchy.

 

With the GTYR tuner, anyone have any tips of what to change to reduce how snachy the on/off throttle transition feels? more fuel on overun maybe (if that's even an option with this tuner)?

G2 throttle, a free flowing exhaust (FMF Q4) and maps that have a smoother bottom end response, like the one attached. 

 

In general, it is the lower left cells (low RPM and small throttle openings) in the table that contribute to the lunging effect just off throttle.    This particular map makes the engine seem almost like a 2 stroke. (Note fuel and ignition at +2 for low RPM and small throttle openings.)

 

I thought the engine was lurchy when I rode the bike stock.  It was much better with the idle set correctly and the FMF muffler.   Add in the map and it is 80% gone.

 

 

 

 

YZ20FX high revving map.jpg

THanks for that MidlifecrisisGuy!

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