Sounds like you are using the gearing calculator I wrote.....

The problem is that the 250R developed peak torque below 8250 RPM & 2 stroke engine power falls off very quickly after peak torque. A stock 250R pulling top gear much above peak torque is not likely.

Many mildy modified 250R's are down 15~20HP by 9500 RPM so if your's is pulling that high you must have some wild port timing or a real top end pipe, stock ones do not like to pull that high.

How were you measuring speed?

Anyhow, my point still stands - we were talking acceleration, not top speed. No one but kids cares about top speed, especially if we're only talking a few MPH.

 

Let's say in an 1/8 or 1/4 asphalt drag, you are telling me that in this drag, your stock 250r would have been even with a stock 400ex? I don't mean to be rude but there must have been something wrong with your ATC.

Also in my experience a 2 mph difference is about good for about 4-5 bike lengths, that is a whopping.

 

Typically ATVs are drag raced 300' in the sand or dirt -- a few sometimes run 1/8th mile on asphalt, but those are usually more serious drag racers with modified quads. No one drags 1/4 mile on stock or even mildly modified ATVs.

In the 1/8 mile stock ATVs are approaching their top speed but neither a stock 400EX or stock 250R will reach their top speeds in the 1/8th.

Yes, stock for stock it would be a very good race between my 400EX (when it was stock) and my ATC250R when it was stock in the 300'. 1/8th mile I'd give more advantage to the R. 1/4 mile drag racing on an ATV proves nothing but top speed.

My 250R still had the stock tires on it when I bought it... I've been riding for over 23 years now & have ridden numerous 250Rs. I currently own 2 3-wheelers (250R and a 350X), 4 bikes (2 Yamaha 80's, a RM250, and a CR500), and 3 quads (2 400EX's and 1 cannondale). I know when one is running right and when one is not. Stock 250R's are not "fast" by any stretch of the imagination. Modified 250R's can be scary fast. Watch sand drags sometime. Most Stock 250R 3-wheelers get spanked by nearly every modern 400cc+ quad, even with the lack of weight and less rolling resistance - I attribute this to the typical stock ones you see out there not running quite as well as when they were new.

The problem most people have is two-fold....

First, many people who don't own a 400EX have ridden a buddy's who hasn't adjusted his throttle or have seen someone race one with the same problem. Performance is lethargic - mine was this way originally and was only marginally faster than a 300ex. 400EX's to this day are shipped from the factory with the throttle cable adjusted all the way in which does not allow the carb to open up all the way. If your dealer doesn't catch it during PDI or you don't physically correct it, it remains that way and your quad is slow.

The other problem is the "legend". That is, either people who remember the stock 250Rs racing against other 3-wheelers & quads of the day & it was "fast" back then. Others have mostly ridden modified units & have forgotten how the power delivery really was on a stock R. Yet another problem is 2 stroke power delivery feeling stronger than it really is due to lack of bottom end.

Stock for stock a 400EX and 250R peak power levels are very similar when both engines are fresh, both in the upper 20's. The 400EX does have more power across the curve, the 250R a bit more peak. It all makes for a pretty decent race as I said in my 1st post. The advantage should go to the 250R, unless it hasn't been well kept - albeit not by a huge margin as some would have you believe...

 

now THAT is what i call knowledgeable posting! lol

 

yea I like reading Gabes post. allways full of good info.

 

Peak Hp at the crank on 250R was 38 hp the 400 ex is about 29. I have both and recently rebuilt the motor in my R. This is the 2nd R I have owned, I bought it about 8 months ago and the the first one I got in 1987 or 88 (the first was mint except for broken fender). The first 1985 R I purchased in 87 or 88 and it had barely been broken in, the kid had gotten it for Xmas and wrecked and put it up as he was scared of it. The R was not very mild, as in stock form, I quite often dusted Banshees and 350x's. It was radar clocked by a policeman at 78 mph on asphalt, as my buddy received like 10 or so tickets and a reckless driving speeding ticket of 78 in 55 zone. It was bone stock with the exception being new rear fenders! This was in 1988 or there about.

i bought a 400ex 1 year ago and it was slow and really still is in a drag race. I purchased a 1985 250R about 8 months ago and it had an engine in need of a rebuild and while it was sluggish on the bottom rpm range it would scream in the high (7000-9000) rpm range. We drag raced my 2 current bikes many times and the 400ex always got the holeshot and about halfway to 1/8th mile the 250 r would go by the 400ex like a rocket, this was pavement, freshly plowed field, sand or open fields. It was a complete joke in 1/4 mile drags the 250r would be 100-150 ft ahead in the end. It made no difference in either rider on either atv the result was always the same. Now with the rebuilt motor it is even a wider disparity in drag racing. This past weekend a friend with a piped Banshee and K&N filter was over and the 250r smoked his Banshee, no matter who was riding what and of course the 400ex was better at holeshot but just doesn't make anywhere close to the HP of the R or Banshee.

I guess in theory and the real world are 2 different stories. My EX has correct adjustment on the throttle cable and there is no way it can even compare to the R. My stock R would have had no problem beating the 400ex by a long shot as Banshees stock will beat the 400ex and my stock R regularly outran stock Banshees on a regular basis. I have no doubt! I have been riding 3 wheelers since 1983 and my real world experience is far different than the theorectical mess this other fellow is talking about!

Where I live there are so many 400exs and it is funny when some of these young guys think that their 400 can beat my 18 year old 3 wheeler. I also recently drag raced a Z400 and while it will outrun the 400ex everytime it also gets dusted by the R. I have hurt several peoples feelings with Craptors as they dusted my 400ex and then were dusted in drag races by the R. The feeling of the R coming on strong in the mid to top rpm levels and coming from behind (usually) to blow right by the newer 5 to 6k four wheelers is GREAT! So get the R and get her adjusted properly and you will know that same feeling!

 

The truth is that drag racing is different everywhere you go. Here in south florida, when we talk about drag racing we are talking pavement and 1/4 miles and high top speeds.

To you drag racing is sand or dirt, no one here would even think of dragging on dirt, the terrain is too rocky so whoever got the jump would roost the hell out of the opponent.

I'm not big into drag racing myself but some people are very serious about it, just this last sunday and the local riding spot, people where racing for $500 a pop. Being that this is about 1/3 mile the top speed is very important. You can believe that those extra 2 miles per hour come in handly when $500 is on the line.

 

First off, 1986atc250r- are you Gabe? (I think that is the name) And you have a nicely built 416? You used to be on here alot, like two years ago, is that right? Were did you go? You always had the best advise, and I see some things never change. I TOTALLY agree with you on every aspect. I have pretty recently built a TRX 250R with the starting point of an '85 ATC 250R. People think that they have superior speed even in stock form just because of the legend and the feel. In a strait line drag, the weight doesn't make that much of a difference unless you are in loamy sand or dirt where the extra weight up front on the quad will really have to push through and the trike would just float over it. The power is nearly identicle (besides smoothness) and on anything other than a nice smooth surface, a stock 250r will have a hard time staying on the pipe in sixth gear. In a steep hill shoot drag, I could slaughter almost anything on the trike and all it had was a pipe, filter and properly tuned engine. But on the straits, I really lost my advantages of weight and floating front tire.

When I finally got it together in quad form, I had to run a stock pipe for a while because of funding. Man was it a shock to realize how slow a stock 250r really is! Even after I got a pipe and had it running really good, a trip to Glamis really humbled me. I could only pull sixth gear on the flats or down hill, period. And I couldn't wait to read the GPS to see just how fast I was going in those eye watering, white knuckled bowls out there in so cal, but to my disbelief, my top speed was only 57mph! Granted, it was sand, but man I was pulling some serious G's in those big bowls. Also, I have taken mine to the local 1/8th mile asphalt drag strip. This was after I got a clean-up port job and it was running absolutely great- my best time was 10.362 seconds at 63.4mph. I was so embarassed. Now before anyone jumps to conclusions, please don't accuse me of not being able to tune my bike properly or say that it was not running right. I know what I am doing with my machines, it's just that most people exagerate emensely.

That 63 mph was not at full on top speed, but it wasn't far off. I expect with that very same gearing(stock), tire(holeshot xc's), and motor setup(bills pipe, mild port-n-polish, uni filter) I probably could have pulled down about 66-67mph in the long run. My guess is that a bone stock '86 ATC 250r would be able to pull a realistic and repeatable 67mph, but it would get there a good bit quicker than a stock 400ex.

Also, If I put some light weight tires on my R like the stock Ohtsu's, I think it would pull around 72mph. Just a guess though. It is great at holeshots, which is much more important to me.

JP

 

Markdb420 you are so full of it. A stock 250r never beat a banshee ever, and it is no where near 38 hp. I race quads at Glamis the toy capital of the world and never has a stock 250r ever even come close to a stock banshee. That is the real world get used to it.

 

speedmn


I don't know why you have a hard time accepting my real life experience. You are full of it! You must live in fantasy land like most others in California! It happened so get over it! Back in 1988 a 85 250r 3wheeler smoked several 1987 and 1988 Banshees, in my fathers fields! I was there, I did it, and I don't believe that in the Glamis litter box that has never happened. The 3 wheeler was way faster than the 4 wheeled 250r and it was pretty common to see 250r's and tecates (which are faster than 250r 3 wheelers) beat the Banshees very often! I guess reality doesn't come in to play in that kitty litter box! Stock Banshees were and still are overweighted pigs and aren't that fast until you pipe and re jet them!

The last drag we did this past weekend with piped 250r and piped Banshee, also ended with the 250r beating the banshee by 5-6 bike lengths in 1/8 mile drag, so tell me I didn't see what really happened, you must be a friggin moron, that cannot accept REALITY!