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 :D

[bradshea]

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?

Are you running a stock pipe? What carb are you using and what jetting are you running?

[Rjfabwerx]

Not saying this is your issue but my neighbor kid who used to race motocross swears by replacing reeds...I replaced the reeds in mine awhile back and that also made a significant difference...don't waste the money if they look good though, mine looked pretty used, lol...

[Auto_Demon]

well does anyone els know what to do to make it faster, i.e parts wise

[Auto_Demon]

well im running a stock silencer stock carb and stock jets, hopfully after this winter it will be faster cuz were rebuilding it and getting new parts, i get some before and after pics

[ebecme01]

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 :)

I took my R out again and I think it was loaded up before. Its still powerful in the lower and mid range but after a few minutes of riding it started to clean up and seemed to pull all the way to the high RPM range. It does flatten out a little but it was sputtering or missing and sounded like it had a rev limiter before. Its still not as fast as I thought it would be though. My cousins Tri-Z is ridiculously fast...I knew an air cooled R wouldn't be as fast as the Z but I imagined it would scare me a little, it doesnt. His bike has a pipe and aftermarket reeds so I imagine that has something to do with it too. I knew you guys would know how each bike runs so I thought I'd get your opinions. I'd never ridden an R before, I've ridden the Tri-Z, a 400ex, Banshee, Blaster, some Polaris sport 400 quad, and lots of 200x s. Oh and I rode a mid 80s CR250 and THAT was scary fast. I only weigh 135lbs and that bike didnt even know I was there. I cant imagine what a new one must be like. I was into dirt bikes when I was a kid and had heard many times that the CR 2 strokes had a much more broad powerband, and I'm glad my R has nice ridable power in the mid range, I just want more. Whats the first step guys?

[beets442]

Forgot to mention this and I can't remember if the 83' had reeds or not, but old reeds will also make it run funny...Beets

[Auto_Demon]

ya mine has reeds they are the stock metal reeds, im getting new ones

[ebecme01]

So Auto_Demon, where are the pics of your ride?

[Dman450R]

My 83 is exactly the same. It's bone stock and on its original bore and first and second gear seem really short and are over in a hurry. It doesn't seem like the power comes on until 3rd. When I finished rebuilding mine I was expecting more out of it as well. I think it comes down to getting the performance parts to uncork the motor. I have a modded 87 250r and a built 450r, a bone stock 83 is just not going to compare.

[Auto_Demon]

well ebecme01 ill get some pics soon

[Auto_Demon]

but heres a vid http://www.youtube.com/watch?v=wG2miUi9d2c

[v8280z]

I just had my first ride on my '84 250r yesterday after rebuilding it for the last few months. I have the exact same problem. At about 2/3 throttle it starts to break up. If I shift up it takes off until the RPM's hit about 2/3 throttle and then it acts like it has a rev limiter on it or something. This is my first 2 stroke and I was expecting a little more performance too. Hopefully after getting it tuned in it will be better. If not I think I might go back to a 350x.... Except for the new Boysen reeds and the hollow unknown silencer I think it is all stock. My first guess is that it is jetting or timing.... I guess I need to tear into it again

[bigbadktm]

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?

I have the very same problem with a liquid cooled R , flutters at full throttle, cant figure it out

[HondaRidr]

I rode a 85 R that did just like you guys are saying, it would pull hard then the power would just quit. My 83 R doesnt do that, it has power from about mid end to high rpms. Its stock besides an aftermarket silencer.

[ebecme01]

Ive only ridden mine a few times, and it has seemed to run out of power at high RPMs. I rode it again yesterday and just did laps in the yard in 3rd and 4th where the low end feels cool... It cleaned out! It runs like I thought it would now. Pulls all the way to the high RPM range. Its still not as fast as the Tri-Z I rode but its pretty fast. I didnt adjust anything I just rode it hard for a while and let it really warm up. Ive been trying to ride a decent wheelie on this thing for days now, it will actually power wheelie now. I've never been able to do much of that with the 200X. Its cool!