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Buddy's RMX

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MY buddy has a 1989 RMX with Pro Circuit exhaust, wiesco piston, higher compression head gasket, and an Airstriker carb. My question is will his bike honestly go 100MPH or more with stock gears, he also says it will dyno right at 50 or better horsepower. I am just wondering how accurate his estimates are?

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I kept telling him maybe 65 mph tops because my newer 250EXC beats him every time and I know it isn't that fast. Of course everytime we race he says, "It just isn't running like it used to."

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With stock gears? No way. With those mods and assuming it's running right he may be able to get to 70.

Get him to do a dyno run on it - I'd like to see it. I believe they put out a little over 40 hp from the factory. Tweaked and configured to RM specs it could be putting out over 50.

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You guys are all wrong. The top speed (terminal velocity) an RMX - or any bike for that matter - is completely independent of it's gearing. In a free fall, an '89 RMX250 will stay "neck and neck" with any year KTM 250EXC, accelerating at a rate of approximately 32 yds per second, per second until obtaining a top speed of almost 200 mph !!!

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66: too funny.

Though an RMX may not bounce as high since it weighs a few lbs. more...

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I actually found a couple of old magazines that have the '89 RMX in it (they were in "the dusty pile". Anyways, the power is rated at about 38 and it has a stock geared top end of about 70mph.

Anyone interested in a couple of old magazines?

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Figure roughly 15% drivetrain loss and it's around 44hp stock. Add RM gaskets, porting, pipe, reeds, carb, etc. and it ought to put out some respectable power. I know mine is a whole lot faster than when it was new.

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the only way my rmx would hit 100 is if it was dropped out of a plane......

just as AJ sayd

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MY buddy has a 1989 RMX with Pro Circuit exhaust, wiesco piston, higher compression head gasket, and an Airstriker carb. My question is will his bike honestly go 100MPH or more with stock gears, he also says it will dyno right at 50 or better horsepower. I am just wondering how accurate his estimates are?

If he says it will hit 100 mph ... I would find more honest buddies ,and dont let him around the wife :) I dont know even if geared tall enough if it would break 100 .

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Not that this is "gospel", but this site http://www.suzukicycles.org/All-Suzuki/all_suzuki_models.html shows that the RMX produced 40hp up to the '94 model, jumped to 51hp for the '95 - 97 models, then back down to 40hp for the '98. However, it also lists '99 and later models which were not sold here in the USA. Consequently, this may not be an "apples to apples" comparison for RMX's sold in the USA. I would have to assume that the 40hp figure is more applicable to (stock) USA bikes since our models came with the very restrictive (but quiet) exhaust, lower compression, etc.. A.J.

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I'm interested.

I have a ton (about 70 ~ so not really a ton) of older magazines that I'm in the process of organizing for sale. The RMX tests did catch my attention, oddly enough they never actually spell out the actual hp or did a dyno pull, but none the less they did like the RMX in '89 a lot.

Although I do remember reading an article on my '90 RM250 and that was rated at 38 hp (the RMX is only slightly less due to it's exhaust). I also did some high speed runs on a friends MX track with a gps tracking top speed. With my '90 RM250 I hit 67mph, on his '91 KX250 I hit 68mph and on his KX500 I hit 76mph. The 500 had more in it, I just ran out of track.

The issues that I have UA that would maybe be most interesting to you is the April '89 Dirt Bike (I've got 2 of those) and June '90 issue of Dirt Bike Magazine. The April issue is a test between the RMX and the Yamaha YZWR-250, KTM-250EXC, ATK-250 and the KDX-200.

It was a very different group, the RMX was their favorite with the KTM, ATK and Yamaha somewhere behind it. The KDX was good with great low end but it just didn't have the beans to run with these dogs.

The June '90 issue was all about changing an RM into an RMX and even changing an RMX into an RM... weird but true. The main deal was the ability of the RMX to hook up because of it's larger flywheel and different power valve setup gave it a midrange advantage. Although the RM with a larger RMX tank was a plus. They were mainly of the opinion that in 1990 if you bought an RM to ride off-road instead of the RMX, you blew it. For $100 more you got way more than $100 worth of goodies (bigger tank, wide ratio trans, lighting coil).

Oddly enough it appeared that an RMX made a better RM than a RM made an RMX (if that makes sense).

UA send me a PM if you are interested in the magazines.

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Yeah my buddy is like that with everything he owns, its all the most powerful and the fastest. No matter what anyone says he will never believe it anyways, I was just curious how accurate he was with all of this. I know he says he can beat any new 450 out there and thats hard for me to believe.

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