Wow !!! I just finished installing the 13 tooth front sprocket and took it for a test ride . Man what a difference 1 tooth can make unbelieveable . anyone who has a 300ex and has changed the factory tires from a 22" to a 20" should consider a gear change . Like I said in another post I had a 250x/350x conversion back in the mid 90's and could never get it to run like it did in 3 wheeler form . I thought it was from going from 3 to 4 wheels with the added weight . But it was the 38 tooth rear sprocket I never changed from the 250x . So I was running a 13/38 set up with 20" tires on the 250x frame . I still have a 14 tooth front sprocket but I dont know if I will be able to reach top speed in 300ft? With a 14/36 gear combo I will have the same final drive as a 400ex but with an extra gear . Anyone know if you reach top speed on a 400ex in a 300ft race? thanks again OHIO BOB

 

I tried the 14 tooth front sprocket and couldnt get it to launch as good as the 13 tooth front sprocket . I am still running the 300ex carb on the 350x . I bought a small cylinder hone from napa ($13.00) and honed my 300ex carb out . It made a huge difference and it was easy . The center of the 300ex carb tapers a lot so I honed it out and removed the choke butterfly . It improved my throttle response and it pulls harder thru the mid range . I like the way it runs and pulls with the new gearing . The quad drags are a week away . I plan on running a 400ex for sure and I am in interested in seeing if all my work will pay off . I will post results thanks Bob

 

i have a 2000 honda fl250 oddyssey with timing issues can anyone explain how to adjust it is backfiring out the intake so its to advanced how do i retard the timing thanks

 

Good day of racing . I did not get a chance to race a 400ex . Not a lot of people this time . I did race a couple of trx450's . I lost by a couple of bike lenghts . My bike ran great the track was a lot rougher this time . And I had trouble launching hard . I lost to the same blaster that beat me before . He has a 240 bigbore kit and a stroker crank . That thing is wicked fast . He ran 54.2 mph exactly 4 times straight . I ran 47 mph and my best run was 51 mph depending on my take off . I ran the 51 mph against the 450r that ran a 58 mph . That gives you an idea about how fast the blaster is . I ran 51 mph in 300 feet and I am starting to second guess Honda's claim of a 70 mph top speed . Yes my motor is in a four wheeler frame and I compensated for my gearing but I dont see it going another 20 mph . I am going yo guess my top speed would be around 60 mph ? My daughter took 1st in the kids quad division . Her Badger 80 ran 30mph thanks for reading my post

 

its good to know I'm not the only one who drag races.

 

As someone who bought a 350X brand new in 85 I can tell you the 350X would easily do over 70mph. This was verified by speedometer, radar, a proven mathmatical formula, and by magazine test.

A lot of it has to do with tires, many of todays tires are heavier then stock. 1lb. of rotating weight is = to 7 lbs of dead weight. Also, the stock tires would balloon up, or enlarge, as your speed progressed. While sitting still you had a 22" tire stock, at speeds over 60 they would increase in diameter to almost 25". this would change the ratio in favor of higher speeds. Most aftermarket tires will not do this.

 

thanks Clinton I like to drag race . You get to meet some good people . What are you racing ?

Black sheep Do you remember what magazine you read that in ? I have a lot of old magazines and cant find it anywhere . I have the first test ride of a 350x from 3 wheel action and the one before that listing the spec on Hondas all new 350x . I have 20" kfx400 tires I doubt they weigh more than a 22" tire but I will weigh my tires and I have a pair of 22" 300ex tires and I will post the difference . I can change my gearing again and make it go 70 mph but it will take forever to get there. In my post I even say I have the motor in a fourwheeler frame and know its heavier . You can even go a step further and say it has 4 tires creating friction instead of 3 . But is that really goin to make it go 10 to 15 mph faster ?

And the tires balloning up to a 25" tire ? Can someone else confirm this .

Another myth about the 350x is it has a 34mm carb its a 31mm .

27hp stock . really around 22 depending on if you go by the flywheel or rear wheel .

a quadzilla topped out at 78 mph . A 350x would not be anywhere around that

This post was suppose to get to the truth about the mighty 350x . I love the old atc and I am searching for a frame to put mine back to an atc . If you have a mathmatical formula to determine top speed by all means post it .

Everybody has a cousin , brother , uncle that has a radar gun or beside them in a car checking with the speedometer. I am looking for facts that can be proved not what someone remembers from 20yrs ago .
Thanks again

 

don't know if I'm reading your statement correctly- but a larger tire will decrease the "displayed mph" not increase it-
unless you're saying a larger tire will increase your top-end mph, in which case is correct, but you'll need more torque to keep those larger tires turning at top speed / top gear.

 

It was the May 1985 issue of Dirt Wheels.

You would be suprised at how light the old Ohtsu tires were. Much lighter then todays tires. (also **** to flats easier, probably why they don't make them like that anymore)

Don't get to hung up on "exactly" ballooning up to 25", I said "about". Keep in mind I am not talking about a quick acceleration moment like a drag tire, I am talking about cruising at a high rate of speed.

No myth on the carb size...it was a misprint in some service manuals.

Quadzillas, were not "fast" at all, they have good torque and power but my 86 ATC 250R would beat one everytime on top speed.

I got the formula from Sidewinder Sprockets, It too was featured in some magazine test and proved to be very accurate. It used to be on thier website, not sure if it still is. If not you can try and call them and get it. I used it to confirm what the magazine said "just over 70mph", what a speedometer said, 72 mph, and what the radar gun said, 71 mph, The formula told me it should be 72.2mph. So for me, that is four differant confirmations. This was done with a bone stock 350X that was less then a month old, on flat pavement. I was able to reach those speeds in less then 1/2 mile.

As far as the four wheeler frame vs 3 wheeler frame? well I have some experiance in that as well... TPC Trikes ...I can tell you that in addition to the additionl weight and the tire drag you mention, you also have aerodynamics. A trike will cut throught the air much easier then a quad. It might not make a differance at 40mph or less but, over 50mph arodynamics start kicking in. (Try wearing a MX helmet with a visor and see how it starts to lift up your head at 50+mph when the wind catches the visor. Then do the same without the visor)..on a side note, another thing people do not know about the 350X, Honda actually did air flow testing in a wind tunnel to check the air flow over the engine and oil cooler. The front fender was designed to channel air towords the oil cooler and over the head to keep the heat down.


Keep in mind during the early and mid 80's things were differant then now, Both the 350X and 85/86 250R's had a 6th gear that was ment as an overdrive. Since 1987/88 with the C.P.S.C. and the concent decree act, ATV's have been heavily regulated by the government and manufactures. No way in hell will we ever see a "overdrive" on a ATV again.

Whether you belive my "memory" or not, is irrelevant to me. I am not some kid on a message board trying to impress anybody. I am simply stating my results from testing this very thing back in 85. Keep in mind that your 350X engine is now over 20 years old, any number of things can hamper it's overall top speed after that many years.

I just read one of your earlier post that mentioned you trying 13/36 gearing with 20" tires. I tried that same thing and was shocked to see I actually lost a lot of speed. Topped out at 65mph. I attributed this to two things, The 20" tires (turf tammers) were heavier, and they did not "ballon" up like the stockers.


Beergut,

I was not refering to "displayed speed" as you put it. I was talking actual speed. As far as torque, the 350X has plenty of it to spare.