RMX top end question

[YELLOWSTREAK]

I've heard that I can use an RM base gasket when I renew the top end on my '98 RMX250 to boost compression and low end power. But I can't tell from the various gasket manufacturers' part numbers which is the one I need. Looks like there was a change in the RMX motor in about '95 and RM's use different gasket numbers almost every year from the late '80's through the '90's. The parts guy at the nearest Suzuki shop to me said, "there's no such thing, it must be a RMZ", so I won't get any help there. Any former RMX owners familiar with this?

 

[placelast]

Most shops won't be much help.

The '89-'95 RM250 & '89-'98 (US) RMX appear to share the same base gasket. See http://www.alpha-sports.com/suzuki_parts.htm.

Eric used to recommend the RM250 '94's barrel and head for the RMX, but he took that sentence out of the second edition of his book.

I send a spare barrel to him and he took some material off of the base. As such it slightly softens the mid hit and makes running in a higher gear a bit easier; highly recommended. While he has your barrel have him port it, reshape the head, and clean the exhaust valve. Good work and pricing. If you have any doubt you can try mine - it needs minor cylinder sidewall cleaning (Scotchbrite; sp?) before use.

 

[YELLOWSTREAK]

Thanks very much for the info. That's exactly the sort of experience I was hoping for. I think I'll look around for a spare cylinder to have Gorr work over. My favorite thing about my '80's-tech scooter is that I can buy whole donor bikes for cheap.

 

[placelast]

I do not know what part of the country you are from but I have two barrels: one for desert and the other for mountains/woods. EG ported both; the only diff is the base machining and head gaskets. Next time I send him work I'll have the other (dez) barrel machined down too, so you may want to do the one you already have.

E-mail me, hit-n-miss@(remove to send)dslextreme.com and I'll share with you all my RMX experiences.

 

[KaTooMer]

I used to use the optional thinner head gasket on my RMX's to get more compression. I think there's an OEM part number specifically for it. Not sure if that's the way you want to go, but another option anyway.

 

[kevlan]

Rmx

For a 98 RMX to improve compression, you need to fit the head gasket off a '96 RM. there is about 2 years differrence in the models from the 97 RMX forward so take the year of your RMX and subtract 2 years to get the equivelant RM part.

Fitting the RM head gasket (Not the Base) will improve compression and give more bang for your bucks. To continue the process open up the airbox by removing the "snorkel" type lid and either get a performance pipe or have the restrictive lining removed from the stock unit - it is a heavy twin wall job with steel mesh inside.
Open up the tail pipe also and remove the wire gauze around the inner pipe before repacking.
Go with an Iridium plug - BR9EIX and set the needlt 1 clip higher in the carby.

Bigo - you have an RMX with its charecteristic low end bang combined with a healthy increase in mid and high range power. This thing will now embarress 2002 and later model MX bikes and scare the bejesus outa your friends! lol

Good riding

K