Hello Kawa forums!

6 months ago, I upgraded my 09 EFI KLX250 with a 292cc cylinder and piston. I used the EJK piggyback controller from Dobeck performance to increase fuel flow. Very happy with the increased power, not so happy with the TERRIBLE milage I have had since.

I've been monitoring my milage and trying to lean out the settings of the controller a little bit in hope that it would improve my milage. I've now reached a point where I cannot really lean it out anymore without impacting drivability, yet I continue to get poor milage.

Admittedly I ride my bike hard and i'm constantly pinning the throttle. I do a lot of city driving and I often hammer through the gears 0-60mph at stoplights and such. Best milage I got was 20km/l(47mpg) and worst was like 16km/l(37.5mpg) Average is ~17km/l(40mpg).

Before the big bore, I would consistently get 25km/l(58.5mpg) and now I consistently get 17km/l(40mpg)

Is there something wrong with my settings or is this normal? The range of my bike is terrible now. I cannot ride 60 miles without the low fuel light coming on.

I think I am going to call Dobeck performance since they have very good customer service, but I just wanted to gather some other experiences before I call them and try to figure out if anything is wrong.

I want to know what kinda milage you get on your big bore bikes? How do you ride to get that milage?

 

Not sure if this will help but I get that in almost stock form, I fill her up around the 60m range.
Dependent on how I ride makes no difference, I could pin it in every gear or ride very conservatively, fuel light always lights up around 60.

I always reset my trip meter when I fill up so when I'm nearing the 60 mile mark I know I'll soon be heading to the petrol station.

 

Wow, thats strange. Before I did the big bore. I would bare minimum go 75-80 miles(US) before the light came on.

 

I have a 351, but I'm carbed and am meticulous with jetting.

I usually get ~75mpg. Worst case is never below 65mpg. I'm not timid with the throttle, but don't abuse my equipment. With fuel injection, you should get as good or better mileage. I hope you can get the issue resolved...

Ron

 

Too rich mid range and wide open throttle jetting

 

Yeah, I'm a little surprised you dropped that much mileage with a 292 cylinder. I realize yours is FI and mine is a pumper carb, but a displacement increase of that size should really only help mileage instead of hurt. I did the 292 OEM cylinder, so my compression ration even stayed the same as the 250. I immediately got a small mpg boost as I didn't have to flog the bike as hard...ability to short shift and such.

I do very little highway mileage where I can get tank-to-tank mileage figures for pure pavement. However, on big loops that involves tough off road, easy dirt roads, and some pavement to connect the loop, I have gotten as high as 63 mpg with the pumper carb...55 is more common as the off road amount increases. I was pleasantly surprised to get better mileage with the pumper than with the CV, but I had seen it accomplished in other folk's bikes. Apparently it's the same effect that I got with the 292 cylinder...more torque, requiring less abusive wringing out of the rpm's on the engine. Unless you did other mods at the same time as the cylinder that are not mentioned, it doesn't make much sense that you would lose mileage...at worst you'd expect the same. With just a 292, did you try running the bike without the fuel controller? I would just about expect the stock setup to be able to handle that, especially if it's an OEM KLX300 cylinder with the same compression as the 250.

 

Yeah, thats kinda what I am thinking as well. The Dobeck performance lets you adjust fuel in 6 different modes. The first 3 modes are Cruise/Accelleration/Full Throttle. In the first 2 modes I use settings well below what EJK recommends. If I lean out any further it feels like the bike struggles and the throttle response becomes choppy. In the 3rd mode(Full throttle) EJK recommends the lowest setting so I cant go lower there.

The last 3 settings change the RPM at which the first 3 settings come into effect. I think this might be where the problem is. I need to be able to change something here I think. I am however confused about this and I think I need to call Dobeck and ask them what they recommend.


I flog my bike just as hard with the big bore as I did before. Atleast on the street, but I still would not expect milage this bad. Even when I ride slow the best I got was 47mpg. There MUST be something wrong.

Honestly even that is much better than what I get.

Actually, once the EJK broke and I had to ship it back (they sent me a new one on warranty no problems). I tried to start the bike without the controller, but it wouldnt even hold idle or throttle properly. It sounded like it was suffering so I quickly turned it off and didnt try again.

 

OK, you want 65mpg, this is the easy way.... and in your case the only way.

Bend down and look at the carb/cable situation, find a way to screw on or put on a retainer that will limit the throttle to 1/4 maximum. Install it. Fill it up with REGULAR and ride it. You will get 65mpg guarenteed!

 

Duriel I dont want 65mpg, just 55mpg like TNC is getting with a similar setup would make me happy

The fact that I am getting 40mpg seems to tell me something is wrong.

 

Well you can get 55mpg, just limit the throttle to 1/3. That was easy.