250 ktm sxf throttle body to yz250f conversion Can it be done ?

tzmike
Posts
437
Joined
2/22/2014
Location
Warwick, NY US
12/29/2019 10:28am
Heard a lot about benefits from the KTM body being used
Even Honda uses it. A keihen to keihen swap seems like the connections would be the same
Anyone do this to there yz ? And are dimensions close and is a harness required to be made for fitment
|
tzmike
Posts
437
Joined
2/22/2014
Location
Warwick, NY US
12/29/2019 10:31am
KTM Keihen sprays from the bottom as the others spray from the upper portion of the body
CarlinoJoeVideo
Posts
7140
Joined
11/30/2013
Location
Portland/Los Angeles, CA US
12/29/2019 11:09am
I think a lot of the race teams use KTM throttle body. I believe Twisted Development has done something like this. They also have the dual injector kit for Yamaha. I just dont know how plug and play everything is with the KTM throttle body on YZF or CRF.
1
12/29/2019 11:58am
I have same idea when i run yzf... But I don't know if it work... If it was me I will try the 2nd injector Smile

The Shop

tzmike
Posts
437
Joined
2/22/2014
Location
Warwick, NY US
12/29/2019 1:09pm
Thanks MadD ! You guys always come thru...
1
cwtoyota
Posts
1557
Joined
3/11/2013
Location
Tacoma, WA US
12/29/2019 4:27pm
tzmike wrote:
Thanks MadD ! You guys always come thru...
Some things you need to know about fuel injectors in general that will help when you swap things around.

1) There are different electrical values used by different injector types and manufacturers.
The easy check is to measure the resistance (ohms) of each injector and compare them.
Disconnect your stock injector and measure across its terminals with a multi-meter set to resistance (ohms).
Measure the new injector you plan to swap the same way with the same meter.
If these two numbers vary by more than 10% you may be risking your ECU to do the swap.

2) There are different injector sizes which are specified by each engine manufacturer. Injectors are either fully open or fully closed. The ECU sends a pulse of a certain length to the injector. The length of open time multiplied by the injector size is the amount of fuel delivered. Obviously if you go to a much larger or much smaller injector you'll be running rich or lean respectively. If you can't find out the exact injector flow rates for each bike up front, you'll have to be careful when you start it the first time.

With item number 2 in mind, and the probability that the airflow is improved (or at least changed) you're almost guaranteed to need to re-map your bike for the swap. With the YZ that may be pretty easy if it's within the range that the stock ECU and power-tuner can adjust.

With the price of used parts for 250F's being fairly low, it would be fun to try it. If you can't map the new parts correctly, you can probably find a shop to help go beyond what the YZ ECU can.
1
tzmike
Posts
437
Joined
2/22/2014
Location
Warwick, NY US
1/4/2020 6:38am
The bike currently has a Vortex ecu on it
Luckily, the bike owner knows 2 different guys with Dynojets
Will do a couple of runs with the Yam keihen, then swap it out and compare the #s. The Vortex is easily accessible in its current but NOT FINAL LOCATION. I'll jot down current settings, then play with it to see if more AND useable rwhp can be had. I'll update the post with RWHP from both set ups
Surprisingly the KTM part# is the SAME for the throttle bodies from the 250,350 and 450. Fyi. Using a 17 450 body.
3/23/2020 1:11pm
How does it go with the ktm throttle body?

Post a reply to: 250 ktm sxf throttle body to yz250f conversion Can it be done ?

The Latest

The Latest