2014 YZ450F + 250F bows

[celler]

Originally Posted by zeuszuki

The 450's flame out as well with a stock map in the woods. A remap + turning the idle up a fraction stops this, it's super easy with the tuner. I couldn't imagine the 250's being any different.
Hot start issues??? It's all in the technique .

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Do you still need technique with the EFI bikes?

[zeuszuki]

Originally Posted by celler

Do you still need technique with the EFI bikes?

The technique I use;
Engine is shut off using kill switch - locate TDC, one long stroke of the kick starter ( if you kick too quickly the EFI doesn't get a long enough power pulse to activate ).
Just crashed and burned - try above , if that doesn't work then pull throttle full on, kick over three times to clear engine ( full throttle while engine is not running stops the fuel supply ), close throttle and find TDC one kick and your away.
It's really that simple.

[zeuszuki]

Originally Posted by GMP

I had a Cannondale I did a lot of mapping on and it worked pretty good for what it was. I'm going to sit and watch this one, there wil be a fair amount of these showing up in my series and it wil be obvious if its a viable option. The light weight, adequate power, and clean external profile is very attractive, but there is no free lunch.

"Not sent from my iPad using Tapatalk HD", pretty funny.

Your right on the " no free lunch " bit. With the Yamaha's the trade off is a very crude injection system ( closed loop as with most other bikes ). The injection makes the throttle response very abrupt off idle, very noticeable on the 450 ( some of this can be tuned out of the OEM system ). With the tuner however the Yamaha's are easy to remap and it's surprisingly effective.
Otherwise I find my 450 pretty easy to live with TBH. One thing people never do is tune the "CO" setting, the GYTR tuner can not do this. Think of the CO setting as a mixture screw setting.

[GMP]

Yes I know I also did a lot with my Ducati. The C'Dale had a very flexible system, you could change everything. It ended up quite smooth and civilized. Maybe a bit premature to judge the 250F EFI?


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[zeuszuki]

Originally Posted by GMP

Yes I know I also did a lot with my Ducati. The C'Dale had a very flexible system, you could change everything. It ended up quite smooth and civilized. Maybe a bit premature to judge the 250F EFI?


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I am looking forward to sinking my teeth into the new 250. The old carb model needed a ton of work to get it fueling right but injection "should" resolve those issues. Being a new 4valve design the horrible step on the intake should be gone for a start ( one would hope ). This motor with its new architecture should technically really breath, a real bonus when your pulling some numbers.
Make sure you drop back with some feedback on them GMP , you guys will get them in the states long before us :-/ .
One thing I did notice was a single comp ring - better be prepared for frequent top end strip downs....