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Emu · July 17th, 2020, 07:01 PM

I actually did a LOT of research on this topic and Danno helped a lot with the initial theory craft of everything.

This all starts at the flywheel, the stock 250 has 4 trigger teeth with one wide one, the 300 has 24-2 pattern.

If I recall correctly the 300 flywheel should fit in place of the 250. The ECU needs these trigger teeth on the flywheel in order for it to function correctly.

As for the throttle bodies. I found a japanese guy who has been trying to get his fuel injected race 250 (yes japan and europe/uk got fuel injected while we got carbed) to reach 180kph on the front straight of his local race track, actually fit the 300 throttle bodies on his 250. I'll link the video lower.

I have not looked into how big the differences are between the 300 and 250 wiring harnesses, I am looking at ordering a stock fuel injected harness from the UK soon (google ebay UK and shop around there for 250 ecu, harness, throttle bodies, etc).

Danno would know more than me about getting that harness to fit/modify to fit.

Next is fuel pump, again the uk bikes had tanks with fuel pumps built into them (found used on UK ebay) which would be the cleanest fit to get it to fit with limited space.

There are multiple little sensors you need for the ecu like air inlet temp, speed sensor at the front sproket, etc to fit so the ECU and dash are happy.

The last thing you'd need is to weld and O2 sensor bung onto the exhaust (ECU needs o2 sensor), you can go for the stock 300 (narrow band) or get an after market wide band to be able to tune it better.

This is a rabbit hole I have been navigating myself for well over 2 months now because I haven't seen too much on using stock kawasaki parts to do an EFI conversion.

https://www.youtube.com/watch?v=cNUUySSPmM0
I watch his videos with english subtitles, I think one of his fans has written the translations now because they were not this good the first time I came across his videos.

I'm sure others in the forum will comment if I forget anything and will add other stuff to the list of things needed.

I follow the 7 P's before I start any project, Proper Prior Planning Prevents Piss Poor Performance. With that in mind, I have been gathering an extensive list of parts and processes I will have to change/do in order to do this right the first time.

July 17th, 2020, 07:01 PM	#2
Emu ninjette.org member Name: Emu Location: Oklahoma Join Date: Jun 2019 Motorcycle(s): 2011 Ninja 250r Posts: 55	I actually did a LOT of research on this topic and Danno helped a lot with the initial theory craft of everything. This all starts at the flywheel, the stock 250 has 4 trigger teeth with one wide one, the 300 has 24-2 pattern. If I recall correctly the 300 flywheel should fit in place of the 250. The ECU needs these trigger teeth on the flywheel in order for it to function correctly. As for the throttle bodies. I found a japanese guy who has been trying to get his fuel injected race 250 (yes japan and europe/uk got fuel injected while we got carbed) to reach 180kph on the front straight of his local race track, actually fit the 300 throttle bodies on his 250. I'll link the video lower. I have not looked into how big the differences are between the 300 and 250 wiring harnesses, I am looking at ordering a stock fuel injected harness from the UK soon (google ebay UK and shop around there for 250 ecu, harness, throttle bodies, etc). Danno would know more than me about getting that harness to fit/modify to fit. Next is fuel pump, again the uk bikes had tanks with fuel pumps built into them (found used on UK ebay) which would be the cleanest fit to get it to fit with limited space. There are multiple little sensors you need for the ecu like air inlet temp, speed sensor at the front sproket, etc to fit so the ECU and dash are happy. The last thing you'd need is to weld and O2 sensor bung onto the exhaust (ECU needs o2 sensor), you can go for the stock 300 (narrow band) or get an after market wide band to be able to tune it better. This is a rabbit hole I have been navigating myself for well over 2 months now because I haven't seen too much on using stock kawasaki parts to do an EFI conversion. https://www.youtube.com/watch?v=cNUUySSPmM0 I watch his videos with english subtitles, I think one of his fans has written the translations now because they were not this good the first time I came across his videos. I'm sure others in the forum will comment if I forget anything and will add other stuff to the list of things needed. I follow the 7 P's before I start any project, Proper Prior Planning Prevents Piss Poor Performance. With that in mind, I have been gathering an extensive list of parts and processes I will have to change/do in order to do this right the first time.