125-200cc What would the 144cc do to the gas milage?

Hearing of the fun factor the 144 brings to most 125 owners; trail riders, hare scramble and motoheads alike, I trying to talk myself out of it for various reasons...

The way the bike is set up now we just ran 2 1/2 hours with the IMS 2.9 gallon tank and have 4'' of gas left. A 2 hour wide open GNCC event with no gas stop!

The racer in me is saying go 144 to help offset the orange 150/200 horde...The extra tourqe and mid-range pull is VERY tempting.

The mechanic in me is saying don't mess with a good thing...the package is ripping. The last thing I want is more motor but having to stop for gas...

I've had some advice/guidence from some cafe people that would make the 144 switch almost too easy, but I am still hesitant.

Any input supporting the different mindsets; racer vs. mechanic would be appreciated.

I'll post the report later, but this weekend the no gas stop thing had him in 2nd until he pulled a ''Mullins like'' next to the last turn dive...wasn't pretty.

i know we had to go ALOT leaner on our jetting with the 144, i would think that would be better mpg but i dunno. i honestly thought in 125 trim our bike was quite a fuel hog...

I have my WR150 up to 18+Mpg. Jetting was part of it and float level was a major issue. I am running a Keihin PWK Air Striker. A 36mm off the 2011 KTM 150XC. The 38mm PWK AS was not much different but harder to jet. I have gotten better overall performance from the 36mm.

I would think you could go slightly taller gearing and come out the same or better.
GP

I am running 13/52 on my WR150 and love it. When I go to the 167 kit I wonder if I should go to 14/52 or 14/50.

Stock...my '08 125cr gets awesome mileage,no problem getting 2hrs on a tank of gas(mid pack b rider),will report back in a few weeks when I have the 144 kit installed.

Thanks guys...I assume with a name like scrambler we are talking 'Hare Scrambles'? And is that with the stock or aftermarket tank?
Mine is actually the '09 WR125 with an '08 ignition. Let me know how that works out...

The worst part is I really don't know if he will benefit from the extra 15% of cc, money better spent on having his suspension tuned again?
The bike is flat out ripping, and since I only have one for practice and racing I hate to mess with a good thing...

Talked to Fred Andrews before the race; cool guy, he came over and watched Andy's start from right behind him.
Andy did not get the best start again, Fred had a few pointers for a better start technique; have a few things to work on.
Andy did mention getting behind some slower riders that the leaders slipped in front of right before a really tight section. At one point he was held up; 8 bikes deep in the scoring area!

Check his lap times, if he can get off to a better start, he finishes strong. I have to post the report, he missed 2nd by going down two turns from the finish.

http://www.racer-results.net/results/gncc/2011/laptimes.asp?e=25&c=48&s=4&r=4

My 06 125 with a 36mm PWK got excellent mileage. If I took it easy on all the road sections I could do a 75 mile loop and sometimes not even hit reserve. This was with the stock 2.5 gallon tank and two extra quarts of fuel in my backpack.
My 09 144 with either a 38mm PWK or the stock 38mm TMXX eats gas at an alarming rate. I swear it uses twice what my 06 does. When summer comes and I want to do some long loops again I am not sure what I will do.
I don’t think the 144 is the problem though. From others reports the 144 usually does better.
I am suspicious that the new cylinder might be less efficient.
I highly suspect the 36mm carb made a big difference on my old 125. If range is a high priority I would start with a 36mm carb, jet it perfectly, and set the float as high as you can get away with.

I have the 2011 WR144 with the stock 38 carb and a IMS 2.9 tank. Two weeks ago was a 2 hour, pretty much flat out HS. I too had about 4-5" left in gas. I have jetted just a hair to the rich side (it runs perfect when you pin it, but may collect some oil at the pipe/silencer junction if it's a super tight trail)

Gearing is 12/52 and I am running the CR ignition. I used a bunch more gas here than the deep sandy course earlier in the year because it was so hardpacked and smooth. (that, and I can't go much more than 4-6 laps in that stinkin' sand)

Dollar for dollar though, I think you would be money ahead putting the money into the suspension. (assuming he is riding the 125 to it's full potential) You can take a slower bike motor-wise, and still win easily, as long as it's handling good.

Good luck!

MXR and NW...Thanks, that's the kind of common sense advice I needed...

This is really his first full size bike, and I have no skills to teach when it comes to wringing out a 125 to it's full potential. I think the motor is making very usable power, but of course, I'm the mechanic, what would you expect. If I knew he was riding the 125 to full potential than 144 it would be. You make a great point...why spend money to compensate for a possible rider shortcoming. He's been to a couple of off-road schools; Raines and Watts, both do a great job covering position, conditioning and attitude. I've actually been thinking about a motocross
lesson or two from some old school 2 stroke racers.

I'm a firm believer that the way to learn to race/ride is 2 stroke...and I think he enjoys putting the 125 up against the bigger bikes and ending up near to top...

Turning the attention to other areas may be the answer for speed instead of looking for more motor...

Thanks...

Here is a link to one of Andy's pic at racedaypix, which has all the weekend photos from the Big Buck GNCC...I thinking of buying this one for him...

http://www.photostockplus.com/home....o&photo_id=43893180&album_id=808439&pcount=44

I like my 36mm PWK Air Striker.

Yes hare scrambles/cross country.Stock tank,ideally it would be beneficial for him to try someone's 144.

The IMS tank is great. Good fit and doesn't feel wider. Good for 50+miles on a tank, with proper setup. An actual 2.85 gallons per Jay Hall.

Getting about 50+ on my IMS. Could not even get 35 on the stocker. Myself and Drew both had epic fails on making the 40 mile mark for gas at Ithica Enduro last year. I was pushing at 38....literally BBBOOOWWWAAHHH!...COUGH ....COUGH....WEEZ OH SH*T!

Too Funny now Joe, but I am sure there was just a tych of frustration at the time.