Kuyarico said:
cool, I'll recheck my floats. I'm pretty sure I've got the floats right. I made my own measuring tool out of an old credit card. I don't think there are any adjustments (notches on the needle). Do you know something about these carbs that I don't?
My wife has a Ninja 250(twin) and had a pretty serious surge problem going down the high way. It's stock other than a K&N filter. I rode it all last year that way and come hell or high water wasn't going to put up with it this year it was that annoying! I talked to to owner of the local dealership and he did confirm they were lean in the middle.
I was all set to jet it up,raise the needles and play with the float levels if need be. The dealer said to not mess with the jetting with the stock pipes and to my efforts into shimming the needles. I've done it on some past bikes,it's NOT a big deal and anyone can do it.
I used to have a bag of Radio Shack washers just for this task,but couldn't find them so,I got my digital calipers and went to the local hardware store. Went through a bunch of SS washers try to match up "mates" the best I could took a few home and install TWO each or .126" total and raised the needles. NOTE: You will probably have to drill the center out a tad larger to you needle to fit through. Remember to clean up any metal burrs,dirt,grease etc. off the washers so they will sit flat and not get metal/grime in your engine.
Turns out that may be just a tad too much for my bike(seems a little fat at abrupt throttle),but one thing for sure it made a HUGE difference in the mid and top end of the bike! I should have done it last year and kick myself for putting up with it for so long. The surging at constant throttle input at speed is GONE as in not there anymore. It pulls so much harder that it feel like the motor just woke up! Before would buck,protest and surge to pick up speed,but now just goes as it should have all along.
Before the bike WOULD not start and run without choking it and running it that way for several minutes/miles. That has be reduced greatly as well and I only have to chock it if I haven't started it in a couple weeks. Even then it only has to run a couple of minutes to be ready to go which is nice because before I would sometimes forget I still had the choke on until I went to stop for the first time!
I tend to lean(no pun intended) to the lean side,but in the 250's case it was just TOO lean as it came from the factory and I'm sure the K&N filter didn't help that any.
On my old FZR1000 I played with the float levels after gutting the header and modding a R6 canister for it(also had a K&N filter in place). It actually ran the cleanest and pulled the hardest when I could HEAR the floats rattle as it started to pull hard. I was too afraid that it would empty them dry and cause moments of lean condition over time,so I set them up couple of MM higher than that.
What ever you do,do ONE change at a time,take notes and do it in small increments. If it starts running worse back off to where it was before. Eventually you'll get close to where you need to be and don't forget to check the plugs for signs of too lean/rich.
Also make sure the carbs are clean and synchronized,no vacuum,carb boots,air filter,float or needle valve leaks.
Remember every bike is different,even two supposedly identical bikes from the same assembly line. Each machine has a mind of it's own and needs tuned accordingly. Ball park figures are just that and get you close,but they are the be all and end all.
