HELP! Getting poor fuel mileage
I don't have any plans to ditch it. I just want to find the sweet spot where I can run the KDX snorkle and FMF exhaust and have the carb jetting where I don't get 30 MPG. I should be able to do that and still get 45 MPG on the trail IMHO. I think its the pilot jet need moved back to the stock setting. Main jet probably doesn't make that much difference as its only used when your dang near WOT. I don't run WOT on the trails, so it kind of rules that out.
My air box is still intact. The only thing I did was switch out the stock snorkle for the KX snorkle, which by my guess lets 1.5 times as much air to the filter as the stock. The filter I posted is not a Uni, its either a No toil or OEM. Since nothing else on the bike has been modded ever, I am betting on OEM.
At this point with my work schedule I won't be wrenching on the bike anymore till next Thursday. Once I get back at it I think my first step is going to be pull the head cover and check the valve clearance. If one of them is out of wack for some reason any jetting I do may not help. So I want to check them before I continue. Then I will pull the N1TC needle and confirm the clip is in the correct slot 2. Then I am going to put a #35 (stock) pilot back in and drop the main jet from the 125 to 122. Install new air filter and plug, reassemble bike and take it for a spin and see how she runs and performs.
At this point with my work schedule I won't be wrenching on the bike anymore till next Thursday. Once I get back at it I think my first step is going to be pull the head cover and check the valve clearance. If one of them is out of wack for some reason any jetting I do may not help. So I want to check them before I continue. Then I will pull the N1TC needle and confirm the clip is in the correct slot 2. Then I am going to put a #35 (stock) pilot back in and drop the main jet from the 125 to 122. Install new air filter and plug, reassemble bike and take it for a spin and see how she runs and performs.
Couldn't agree more. I had some on a road bike with CV's and it worked out fine but that bike was built to run at all RPM. With this bike, I wouldn;t get too far from engineered success. Good luck Landon. I hope to catch you on the trail one day soon!
I ended up having my day free up today and got some things done...
Ok. I got the carb done and reinstalled. I put the stock needle back in and essentially did a 22 cent mod (place #4 flat washer under needle). I ended up leaving the mian jet at 125 and put the pilot jet back to stock 35.
I also checked the valves today. I was not really prepared to do that today and had to settle with a feeler gauge set from the auto parts store. It didn't really have all the gauges I would of like to have, but it had enough for me to figure out all the valves were within spec, although I plan to check them again with a good set of gauges withing the next 1000 miles as a couple of the valves seemed like they might be getting close to being out of spec.
Last thing I got done is pulled the OEM auto tensioner and installed and manually adjustable one.
My new air filter is in and I just have to go pick it up. Then install the tank, seat, and plastics and go for a ride.
Ok. I got the carb done and reinstalled. I put the stock needle back in and essentially did a 22 cent mod (place #4 flat washer under needle). I ended up leaving the mian jet at 125 and put the pilot jet back to stock 35.
I also checked the valves today. I was not really prepared to do that today and had to settle with a feeler gauge set from the auto parts store. It didn't really have all the gauges I would of like to have, but it had enough for me to figure out all the valves were within spec, although I plan to check them again with a good set of gauges withing the next 1000 miles as a couple of the valves seemed like they might be getting close to being out of spec.
Last thing I got done is pulled the OEM auto tensioner and installed and manually adjustable one.
My new air filter is in and I just have to go pick it up. Then install the tank, seat, and plastics and go for a ride.
Last edited by Landon; Jan 8, 2012 at 10:00 PM.
I replaced the spark plug also.
I don't know that I have it worked out yet, but in my opinion it the N1TC needle thats the biggest issue. I don't know if others using it have ever checked their MPG.
I don't know that I have it worked out yet, but in my opinion it the N1TC needle thats the biggest issue. I don't know if others using it have ever checked their MPG.
Dan
I have the N1TC needle with a 351. With mixed street riding,I usually get over 65mpg. I get correspondingly good mileage on the trails. For example, I got 60mpg on a 100+ mile loop on the Paiute trail system in Utah. That is mostly single track.
Jetting can be a complex issue. It's a matter of making everything (intake, carburetor, exhaust) work together.
Ron


