air cooled 250r speed issue

[Auto_Demon]

i have a 1983 honda atc 250r and it is lacking major speed, its doing 70km/h, ive heard them doing atleast 100km/h, ive gottin a carb rebuild kit,uni airfilter and new bearings, what else should i do and what is happening to it??

[Xpress]

Have you measured that with a callibrated radar? That year should do probably a bit over 100kmh.

[dcreel]

What size are your tires, and what is your gearing?

[Auto_Demon]

im using a GPS, my tires are 22x11x8 and its the stock ratios but im getting a 15 tooth front sprocket this winter, how much change would that be?

[beets442]

Carbon built up in the tail pipe? that'll dog a 2stroke....Beets

[Rjfabwerx]

Carbon built up in the tail pipe? that'll dog a 2stroke....Beets

I took the guts out of my pipe and it was TERRIBLE like coal in there...cut that used-to-be-white crap out with my pocket knife, reinserted the steel guts and screws and it made a HUGE difference...

[D-dub]

Ill buy it.

[ebecme01]

Im going to piggy back on this thread if I can. I also have an 83 250R and have a question about the power it should have. Its by no means slow but I expected it to run differently than it does. First and second gear are over instantly and when you get to third you can feel how much power is there and where the power is. The odd thing is the powerband. The 2 strokes Ive had in the past didnt really have much power until high RPMs and then they were screamers. So I'm used to riding them in the high RPM range. My R has loads of power right off the bat but then seems to flutter in the high RPMS....so I shift and it pulls like crazy then again seems to flatten out. Is this because its stock? To get the power in the high RPMs do I need better reeds, jetting, and a pipe?

[Auto_Demon]

well its the stock pipe has no baffle and it does look very dirty but how do i clean it?

[Auto_Demon]

D-dub, im rebuilding it this winter and im probably going to sell it after that or trade for a atc 350x

[dma550]

Im going to piggy back on this thread if I can. I also have an 83 250R and have a question about the power it should have. Its by no means slow but I expected it to run differently than it does. First and second gear are over instantly and when you get to third you can feel how much power is there and where the power is. The odd thing is the powerband. The 2 strokes Ive had in the past didnt really have much power until high RPMs and then they were screamers. So I'm used to riding them in the high RPM range. My R has loads of power right off the bat but then seems to flutter in the high RPMS....so I shift and it pulls like crazy then again seems to flatten out. Is this because its stock? To get the power in the high RPMs do I need better reeds, jetting, and a pipe?

The "powerband" you are describing is a peaky powerband, like on a MX bike. Plenty of two strokes are tuned to perform at lower RPM's, it's all porting, pipes and induction, with a touch of flywheel and ignition "retard" to smooth things out. Honda didn’t just drop a CR250R engine in your 250r's frame, they detuned the engine through ignition and porting to make it mass-market friendly.

Also, CR's have always had more of a strong mid-range than other MX two strokes, and is why we mod them into Enduro weapons

[ATC-RYDA]

Puttin a pipe on there with a baffle will probably help or just getting a baffle for the pipe u have ... No baffle = no back pressure on motor

[Auto_Demon]

well im getting a DG silencer over winter so....

[KASEY]

Puttin a pipe on there with a baffle will probably help or just getting a baffle for the pipe u have ... No baffle = no back pressure on motor

ITS A 2 STROKE not 4 ,, it does not need backpressure..... it works on sound waves and a silencer won't make it faster,,,,,,,,,,,,

[Xpress]

Throw some alcohol in your fuel, that'll give you a good speed boost