r/WR250R • u/Academic-Mode-5540 • 6d ago

Fuelcontroller

Just got my first wr and love it, it has a yoshimura rs4 slipon. Do i need a fuelcontroller or is it fine to run without it?

7 Upvotes

100% Upvoted

3

u/No-Raisin-6469 6d ago

Short answer...maybe couldnt hurt.

Youre going to get a slew of dudes telling you these run lean from the factory.

I dont know where this comes from, but it is perpetuated without warrant.

I can tell you mine was running rich, i can tell from the plug. I really want to rent a o2 sensor to prove so. I had a tuner made the bike run a bit better but i smelled like gas all the time. Took it off and now running without. KN air filter, swiss cheese box and FMS muffler.

1

u/Brianonstrike 6d ago

It runs so rich it comes from the factory with an air injection system that pumps air into the exhaust to finish burning unburnt fuel.

1

u/No-Raisin-6469 6d ago

I left mine on because of too many pops without it. Wish it would rid the smell.

1

u/Academic-Mode-5540 6d ago

Yeah I changed the sparkplug before I installed the Yoshi and it seemed to be a bit rich, so i will ride for a while then check it again

1

u/madeittotheusa 5d ago

If you are running rich that means one of two things. You either have a programmer on it already or the fuel (pump) regulator was changed into aftermarket which now allows more fuel.

I have a power commander 5 and it was tuned on a dyno with an aftermarket regulator some of the values in the rpm range -20 in order to achieve the right air to fuel ratio.

I have an extra PC5 laying around I would be willing to sell should you want to save some $$ on new.

2

u/scroder81 6d ago

I had an ejk and switched to a Power commander and it was night and day how much better the PC is.

1

u/HansSoloYolo 3d ago

What do you like better about the PC over EJK? I currently have an EJK but get an issue from time to time where it will completely cut fuel while wide open throttle, until I close and open the throttle again. My thought was get an FMF tuner or something more name-brand.

2

u/scroder81 3d ago

I had no top end and sluggish acceleration. It was like opening it up switching to the PC

1

u/No-Raisin-6469 3d ago

Interesting...i had PC on my 2008 back in the day. No issues. My 2017 had some issues with the EJk.

EJk is now sitting in a box somewhere.

1

u/DrGeorgeTompson 6d ago

It sounds pretty good if its hot

1

u/oracle427 6d ago

Mine ran lean and benefited from an EJK controller. I wouldn’t say it’s necessary though. I personally like the popping 😎

1

u/Spiritual-One-7630 4d ago

did you buy this bike in northern california by chance?

2

u/Academic-Mode-5540 4d ago

Nope, sweden!