RMX sits low in the stroke front and rear, which limits the amount of useful suspension travel and makes slamming into hard objects a metal-to-metal proposition. The standard fork springs on this bike have been replaced with
heavier .42kg Race Tech springs. The stock shock spring was replaced with a
heavier Race Tech 5.0kg spring. The swap makes the bike sit higher in the stroke and has also made it less , twftchy. Spring Swap: $309.

The RMX250 became a big sales success when Suzuki had the good sense to ADR the bike so ordinary blokes could ride it legally on the road. (There's nothing worse than dodging coppers on the way to your favourite riding spot, then being nabbed coz you couldn't outride Constable Grinder, right?)
It's common knowledge that the current RMX250 was devised with input from Australian riders, and no surprise to anyone that the bike has sold so well. The RMX retains a few old-fashioned accessories, the headlight and somewhat dated plastics, but it's a very nice bike to ride and has all the attributes for which Suzuki is renowned. Australians wouldn't buy it if they didn't like it. and but it they have.

As you'd imagine, the factory set out to make this bike as attractive to as many trailriders as possible. That, of course, made sense, but a certain amount of compromise was necessary. Building a super-aggressive bike was pointless because the thing was supposed to be a trailbike. not an enduro bike. So Suzuki gave it punch, but not a killer punch. The same could be said for the suspension. The bike had to be sprung for trail work and short-to-medium stints on sealed surfaces, so there was no point giving it McGrath suspension in a supercross package that'd pulverise your organs. "Hey. Ma. I'm bleeding from the liver" was not the name of the game.
No indeed. So what compromise eventually produced was a damn nice bike, but one that was softly sprung and. for hardcore desperados, one that lacked the aforesaid killer punch.

The stock PJ38mm Keihin carb won't idle cleanly because the choke and the idle control share the same air passage. If you adjust the PJ for good idle, it will run on. and if you adjust out the run-on, it won't idle. Bummer! Race bikes don't have to idle but trailbikes do. The solution is to swap the PJ carb for the more tuneable 38mm PWK Air Striker carb. The Air Striker was the carb used on the 1997 RM250. From the 98 to the 2000 carb. the only difference is the addition of a powerjet. RMX owners who went to the Air Striker said it makes a profound difference to the bike's performance and gives much better throttle response. Jay Foreman can jet the Air Striker for you. or you can DIY. Here's Jay's jetting: 45 pilot. 1468 needle on the centre clip, #7 slide and a 178 main jet. Air Striker carb: $340.

The standard pipe Is a twin-skin unit with an integral baffle. It's heavy and stifles performance. Fitting a Pro Circuit pipe and silencer freed up the exhaust system and made the engine more responsive. Exhaust system swap: $634.
We've ridden the modified bike, so we know how much better it is. but we didn't leave it there. We also dyno'd the RMX250 to make sure the fast parts were actually doing what they were supposed to do. The test unit was a Dynojet 200. set up at Graeme Morris Racing in Newcastle. The RMX was assessed in standard trim first - no restrictors and the standard carb - then with the Pro Circuit pipe and silencer and the larger 38 PWK carb.
As you can see from the graph, the Suzuki picked up about 2hp and the effect kicked in at about 7200rpm. The stock RMX250 made a sfiver more than 36hp at about 8800rpm. With the mods fitted, output peaked at about 38hp at 8500rpm. so the Suzuki was making better power at lower revs. There's very little significance in the comparative outputs until 7500rpm, so most of the horsepower gains were made in the top end.

Ergo, the RMX250 needed more suspension and more motor.
There are several ways of going about this, not least of which is transplanting RM parts to the RMX engine and chassis. But that's expensive and definitely doesn't make sense if one of the reasons you bought this bike was the more-than-reasonable purchase price.

We're not all millionaires and. of course, increased performance always comes at a price. The components we're about to discuss will set you back about $1300. That's a lot of moolah. But the upside of this particular cash exchange work is noticeably better performance, more surefooted handling and a tingle in the arse that tells you your RMX250 is now better than it ever was. If you invest in this particular powerplay, we guarantee you will have a more capable enduro bike and a machine that will also serve you well as a club day motocrosser.

All the components discussed here can be purchased from Suzuki race team manager Jay Foreman. (02) 49668097. The components can be bought separately or as a package. Ring Jay. He's a nice bloke.

How to make your RMX-250 go like a dog shot up the ass!!












Article by: Dirt Action Magazine

The RMX responds very well to some tuning work, even if you keep all the standard
components. Starting with the simple things, removing the airbox lid helps a little
with airflow, but removing the mesh inside the dual wall exhaust is a bit more difficult.
There's also a few opportunities for weight saving if you've got the cash, including a
lighter headlight unit and replacing the whole rear subframe/tail-light unit with one
from an RM. The standard bars are crap and have never been popular with complaints
about their width (too narrow), their shape (too swept-back) and their strength
(or lack thereof). I replaced my bar with a TAG Metals bar purchased from Action Suzuki
in Parramatta ($85), I found them to be light and very strong. Also some riders swap
the standard rear SOT sprocket for a 49T.
Suspension $309
Carby Swap $340
Pipe Upgrade $634
Handle Bar Upgrade from $65
Mesh Removal $0
Lighter Headlight from $80
TOTAL : $1430