Clutches

**Rmxer** · 19th May 2007, 16:52

Hi there, have a 98 RMX250 and was wondering how you can tell if your clutch is functioning properly with out pulling the thing to bits. Just wonder sometimes if it is pulling up top end as much as it should some times.

cheers

**Buddy L** · 19th May 2007, 17:11

Just remember that the RMX dosen't have the top end power, that a RM has,
Have a quick look at the clutch leaver and make sure that their is a little bit of play in it. (might just be wrongly adjusted), if you have run out of adjustment it may be time to get some new clutch plates.

**cheese** · 20th May 2007, 19:49

Sounds like its slipping. you need to pop it off to look at the plates. Probably need new plates though.

**F5 Dave** · 21st May 2007, 17:53

Why does it sound like it is slipping? Can you hear it all the way from Auckland?

The test is to (once bike has done some miles & is properly warm) uphill load it up (say 3rd) coming into power. If the revs soar it is slipping.

Better yet would be a sandy section & whap on the throttle.

Chances are the RMX is badly jetted/filter/plug & it loads up so doesn't pull cleanly. Just a thought from my short ride on a neglected one.

**cheese** · 21st May 2007, 18:42

I have super ears, like that person on heroes..

**Rmxer** · 21st May 2007, 21:02

cheers for ya help
theres no way it slips under load i was thinking it could just be slipping up in the high rpms, but thinking about it i guess if it was stuffed it would slip under load and not high in the revs.
No this isnt a negelcted RMx thats for sure, when it goes good it goes real good , wouldnt trade it for any other 250 2stroke that would be down grading!

What jetting etc woudl you guys recommend? Mostly trail ride, mixture of fast and slow stuff, do the od enduro.
i also read on here that the RMXs need a B8RES? this true??
i just use a B8ES

cheers

**F5 Dave** · 22nd May 2007, 10:16

The R is just a resistor to reduce interference. Google to find the right plug, but some RMs of that era had expensive plugs that were more robust as vibration failures were common, guess RMX would be similarly affected.

Really jetting is specific to a particular bike if modified, but a good starting point for base model is sometimes gleaned from tuning info available. Lot of KDX info about, maybe there is a RMX website, failing that try DRN.net. Eric Gorr covers the RMX comprehensively in his 2nd edition of his excellent tuning book. -Which reminds me my copy is out on loan.

Start with decent airfilter & confirm carb is clean & emulsion tube (that needle goes into) isn't ovalised, even slightly & the slide hasn't gotten grooved. With any of these faults you can't get started. From there it is a trial-feel approach concentrating on throttle position, not revs. Plenty of articles on the internet on jetting 2 stroke carbs (that are quite different to CV carbs).