First off, I just discovered the speedometer on my bone stock KLX 250 is off about 3-8 miles per hour depending on the speed. When Im cruising along at supposedly 60 MPH, im actually doing about 53 miles per hour. when im banging er out at 75 miles per hour im only about 67ish... this was according to my GPS... Has anyone else experienced this problem? is it normal? if so, how can I fix it?

Next, if I installed the 351 kit and a pumper carb, could I cruise at 65-70 miles per hour at about 6-7 grand? I don't like to go above 7 grand on the hard stuff when cruising distances... I only weigh about a buck 68 fully clothed and heavy booted.. a bill 65 in shorts and shoes... I dont care to do any faster than 65 really, because I never ride on the interstate... just too wobbly and too many ********... you can literally feel the wind blowing you... haha, when i was behind my friend riding my bike, i could just see him swaying, and it looked pretty ****ing dangerous. haha.

Finally, how much will gas mileage reduce if I installed the aforementioned? Right now Im getting anywhere from 45 miles per gallon if I get all over her and wind her out, to almost 70 if I baby her and cruise no faster than 45-50...

THANKS AGAIN..

 

Speedo is normal they are all off.

If you are only riding on the road and you do the 351 you can gear the bike up a bit stock is 14/42 you could go 15/42 or 14/39, that would drop the revs around 600 - 700 revs or thereabouts giving you approx 5300 at 60mph indicated.

Fuel mileage shouldn't change a lot if it's tuned right, depends on how much you twist the throttle.

 

I'm running 15/39 with the 351. It can easily do 70 (gps) at about 7k, but I'm also running an sm setup. I haven't checked it with stock wheels.

 

stock wheels would be faster by...... 10%?

 

thats what im wanting to hear...

does anyone have experience with a pumper carb? i heard it REALLY gives the bike some pop with the snapping of the throttle.

 

The pumper gives you better throttle response, the trade off is it can be a little jolty at small throttle openings. You only notice it on the road when backing off and gently opening the throttle. The pumper carb also makes the bike a lot easier to start. One or two twists on the throttle, choke and the bike starts straight up.

 

so maverickaus, basically what im hearing is once i get the pumper carb and 351 kit, I will have ALL the power I need and then some? Im only interested in being able to cruise comfortably at 65 REAL SPEED... and mainly focused on "trail riding" power.. and I just want to have that snappy, poppy throttle response where the front wheel can be stood straight the **** up with a simple snap of the throttle and a slight pullage on the handle bars... but it's not like real jolty, or dangerously annoying with the pumper carb, right? ANd should I get the 33? 35, or 36? what would u recommend? and what are, if any, the key differences between the aforementioned pumper carb sizes?

Im so excited now.. I think rather than paying my bike off, im going to focus on these mods ...

Once again, pardon my ignorance, and thank you good sir for answering my questions...

 

you are going to upgrade to the 351, the 36 carb will give you the best performance. Do you plan on a bigger gas tank? Just curious.

 

The speedo for almost any motorcycle is going to be off. Mine was 5 mph too fast @ 50 mph. Just re-pluck the needle a little bit to correct the error. Its not perfect, but it works good enough.

A 351 should give plenty of power for speeds up to 75mph or even faster. Stock, the KLX can hold its own at 65mph but no faster. And with more power, you can re-gear to lower the rpm's.

Fuel range for a stock KLX is about 90~100miles on main, and 120~130miles till empty. So it is about 65mpg for the 250cc. It will probably drop to around 50~55mpg on the 351cc. Owners of the 351cc can confirm.

 

Its not exactly a chicken, now is it?