Just wondering- the stock 650's top out anywhere from upper 50's to almost 70. Does that mean that with no modifications other than carb. adjustment or different jetting that bike runnings upper fifties could at least get into the low sixties. If not, why are some bikes so much faster than others. Granted that elevation, outside temp, and humidity along with the driver's weight all affect top speed, but could a bike be finely tuned to gain more speed?

 

Hah! I wish there was a **** to turn it up. Maybe someone is cranking the throttle limiter on our ride without us knowing?

The belt wear affects top speed. you probably knew that.
The CDI was programmed to reduce power at high RPMs (or we would go faster)
Heavy tires kill it, you knew that.

You probably know all that stuff.

I feel that a lot of us aren't jetted right for top speed. I haven't gotten to the bottom of this theory yet, and I haven't spent much time on it. Maybe I will do a little on it tomorrow. Some people think we are lean some say rich. I have a bunch of jets. I may just go try a few sizes either way and just test for top speed.

The bottom line is we should be going faster with these airbox mods and aftermarket air filters. Aside from tires, I think our problem is fuel mixture.

If I'm right, it may mean getting main ait jets, since when we jet our dynojet kits just right, we seem to run better overall but lose top speed.

 

It is upsetting because I have spent money on a full exhaust system, jet kit, aftermarket air filter with box mods, (snorkel is to be here tomorrow) and still have bone stock 650s that are runnning faster. Maybe I need to spend more time trying to adjust mine better. I gained alot of low end power and 3mph, but others say they run 70 stock???

Nyroc, if I remember correctly, you live at a low elevation. Are you satisfied with your jetting combo? I am running 132f, 136r, and 5th notch. Maybe I am too rich.

 

I don't think you are rich if you are at low elev with a pipe.

I like my jet kit. With diameter correction, my 650 does 66mph. I just feel it should do more with the airbox mod, jet kit and filter.

I think I can sense it running just a touch rich and then leaning out a little about 50mph, and getting a little too lean over 60. The only good way to fix that is main air jets. My main jets are right on now, if I richen up the mains, it would simply be a fudge for not having the right main air jet.

I'm not sure though, since dynojet jets are supposed to richen up the top speed, maybe we are too rich. I could easily use a jet dril on the air jets and try that.

 

OK crash, DYNOJET claims that their main jets make the engine leaner at top speed. You can read it on their website. I really feel that this corroborates my lean theory.

Now I will just have to test it. I will go ridin with some richer main jets and see what happens to the the top speed. I could be wrong, don't care if I'm wrong, just wanna know.

I think we are all lean. I think kawi started the top end off a touch lean, then the airbox mods leaned it worse at top speed, and the dynojet made it worse yet at top speed.

 

I know in cars if you loose top speed then you are lean and need to go to bigger mains. I have only road it once in the past 3 week[img]i/expressions/face-icon-small-sad.gif[/img] and I am waiting to recieve my intake. I live in the city so it is hard to mess with the mains and test it after each mod. I plan on after the intake mod is to take it up to a buddies house up the mountain by the strippens and do some testing on it there. Keep us posted on what you find though.

 

I know you all probably know this already, but the P650 does come with a youth-quad like thumb throttle limiter. Meaning.. there is a lock nut and a screw that you can turn in to limit the thumb throttle travel. Thus limiting top speed. Mine is backed all the way out, but when my nephews were riding it, I had it adjusted down to where the quad wouldn't go over 13mph!! So that might be one thing to check if your top speed is in the 50's.

 

Buckeye---I turned your's down last Sunday, when you weren't looking. I was afraid you'd hurt yourself with those stock tires!

 

Try inflateing your tires with more air, you will go faster.

 

4-Man, I wondered what was up! HA! Yeah those stockers are dangerous, but they are long gone now!!! I'm on the Wrecks' Setup now.