Ive owned the bike for about 1 year now, 2001 rm 125 have never changed the oil or done anywork on the clutch other than a couple of levers and cable.It worked fine but i didnt ride for it one year and when i got back on it id start it up and put it 1st gear and nothing would happen???

I am sure it's a wet clutch. Pop your bike in neutural. Remove your clutch crank case cover and, using a screwdriver, separate the plates manually. Put the tip of your screwdriver between the edge of the clutch plates and turn the screwdriver. It will break the seal of your plates and spacers. Put it all together again. Do a fluid flush and refill your oil to recommended levels. Get the bike running again and give it a go. Should be fine. Good luck!

You can run Motor Oil in the Tranny or we run Automatic Transmission Oil in ours and we change it alot. We also run Lucas 2 Stroke Oil at 40:1. We run our Banshee and Yamaha Dirt Bikes on that also. Hope this helps.

Have you made any adjustments to the clutch cable at the lever?
This is basically the only clutch adjustment. If the adjustment is maxed out then it's time for a new clutch. Depending on your riding experience, riding conditions and total time since the clutch was replace or it not then since the bike was new, it's an item that needs to be replaced now and then just like the brakes.

If you know this great. If not read on.

If you intend to continue to own and ride this or bike you are going to want to learn as much about them as you can. This experience is just as important as riding experience. I have been riding my entire life and at least 1/4 of my off-road rides would have ended if not for knowing how to wrench on the bike anywhere.

Changing out a clutch is not difficult unless you have zero mechanical skills and no tools. But if you have basic skills and tools it should be no problem. The picture below is a diagram of your clutch, (under the clutch cover). It can be done in 3 to 4 hours.
Although someone with good mechanical skill could do it using just the diagram, my advice is buy a repair manual.

I really hope this helps but if not or the clutch is new and giving you these problems please let me know and I'll help from there.

It does have a small bolt on the clutch cover, with the bike standing straight up, fill it untill the fluid runs out of this hole.

First, try the cable adjustment at the lever end, if no more movement re-adjust inwards, then adjust at the clutch end.
If no joy, then it is either the lifter mechanism or the clutch its self.
Ride Safe
Bike-Doc

Please mark this as useful (if it has been!!)

What type oil in your crankcase? Wet clutches go on strike with wrong oil. Engine oil is a no no.

Okay, this may take a couple of comments back and forth but I can get you back on the road. First, Have you done any work on the clutch lately? If so, what and why? Did the clutch work okay after the work? Have you changed gearbox oil in the last month or so? If so, EXACTLY what oil did you put in the gearbox? i.e. "10w40 Mobil Super Blue fluid with silicone friction limiters". Just post a comment to get back to me.

Adjust the clutch cable to allow about 1/4" free play at the end of the clutch handle. Don't put the bike in gear until the rpms are near idle speed. The clutch is working fine if the bike does not lurch forward when going into gear at idle speed. Dirty, gritty oil in the gearbox can make the clutch grab. Consider changing oil if grabbing is the problem. The "crunch" you hear is the slider gear engaging into the driven gear. The higher the engine speed when being put into gear the louder the crunch. The slider gear engaging "dogs" can break. Crunching into gear is hard on the gears.

Post a comment to let me know how you come out on this.

You are saying that with the clutch lever pulled in the bike still wants to go forward. Generally that is caused by dirty, gritty oil in the gearbox. Go ahead and change the oil. 10w40 motor oil is what you want. I think that will fix the problem assuming the clutch plates were installed properly. The first plate installed and the last plate installed should be a fiber friction plate, 8 plates total. A metal pressure plate goes between each fiber plate, 7 plates total.

Be sure the lever assembly arm is installed so that it gets full movement of the clutch cable. If the full range of movement is not present then full disengagement of the clutch is not going to happen.

cape cod bob did you a good service in the manual referral. Be sure to say thanks.

1) Can you push the bike while it's in gear with the clutch pulled in? [If so, clutch is disengaging OK]

2) If not, check when you pull in the clutch lever that it pulls all the way through to the actual clutch [If not, replace broken clutch cable]

3) If so, clutch is binding. Either fix it properly by stripping the clutch.. or just brute-force the plates apart. :-)

Brute-force clutch plate separation: First make sure you have enough oil in the engine (wet clutch), then basically you're looking at either riding it with the clutch lever pulled in until the plates come apart or with the rear wheel in the air CAREFULLY running it in first gear against the rear brake while the clutch is pulled in.