What oil for yz 125?

If the clutch drags you need to check the plates and the worse thing to do when a bike wont crank is to pop start it you just do more damage and defiantly only use the right oil

A very common problem with wet clutches is that many folks do not use the correct oil. The plates in the clutch are sandwiched under spring pressure and there is nothing in the mechanism to release them, so if the oil creates too much "stiction" then the plates can become suctioned together.

I suggest first trying an oil change using an oil designed for use with wet clutches. Then, get a running start, hop on the bike and drop it into gear. Then pull in the clutch and while holding the clutch lever in, rev the motor to break the plates loose. If this fails after a few attempts, your plates could be rusted together - possibly from a leaking waterpump seal or a ride through deep water. A simple tear-down of the clutch will tell the tale and this can be done without buying any parts if you are careful.

This sounds like dirt and grit in the oil is causing the clutch to grab. Change the gearbox oil. Ride the bike for a couple of hours using the clutch often. Now drain the oil again and put in fresh oil. This will flush out the dirt and grit. Use 10w40 motor oil. Stick with the major brands; Pennzoil, Quaker State, Mobil or Shell. Do not use synthetics or oils with "special" additives.

Other possible causes are > a need to adjust the clutch lever for 1/4" free play at end of the lever > warped clutch plates or friction plates > Clutch has been worked on and assembled wrong > low oil level in the gearbox > frozen clutch hub bearing > Incorrect clutch cable being used.

Please post a comment after the double oil change. The 2x oil change is a cheap way to eliminate a possible cause and hey, it isn't gonna hurt anything. If you still have the problem I can help with a clutch rebuild.

if you know how to split your case, take the broken case to an engeneering shop that can can do alloy tig welding and get it welded

The problem did not start untill the 10w30 Honda transmission oil went in. It isn't the 10w30 thats the problem. It's the TRANSMISSION oil as opposed to MOTOR oil. There is a difference. As I said before, the swelling may or may not go away.

Best wishes Ryan :)

Nothing significant, don't worry about it. You do NOT want oil marked EC, signifying energy conservation. Such oil will cause the clutch plates to slip and premature clutch wear. If the oil you put in does say EC on the small round type seal simply drain it out and put in the correct oil. Not critical but the sooner the better.

The clutch and gearbox share the same oil. The oil for the motor is 10w40. Stick with the major brands; Pennzoil, Quaker State, Mobil, Yamalube or Shell.

hi m8,,this might sound stupid,, but in winter dayz and salty conditions ,cables corrode in side,,so i can start some where to help,, 1st take the cable off the handle bar,, and the clutch casin,,get a little bit of oil in a jam jar or any thing like that,,dip one end of the cable in the oil ,and keep pullin and pushing the inner cable as if u were trying to draw oil up threw the inside of the cable ,, turn cable the other end and repeat,, try that 1st m8,, still have probs come bk, and il go threw the next step,,

Lose the Honda transmission oil. It may have swollen the cork on the friction plates. Go with 10w40 in the gearbox. Any major brand; Mobil, Shell, Quaker State, Pennzoil, etc.. Try the new oil and give the cork a week to shrink back down > if they will. You may need to put in a new set of plates.

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.