Clutch hub.... Success!

I posted last week about a stubborn clutch nut and got some feedback from the Yamaha facebook group. I put the bike in 4th gear and used my socket with extension bar and still couldn't get the nut to move. What I really needed was an impact wrench but my compressor was 50 miles away in my other home.

There are electric impact wrenches which have become popular recently , I've seen the ads in my fb page, and I was toying with the idea of getting one. I got off work a bit early on Friday and on the way back I stopped by a hardware shop near my house and they had a promotion for power tools. The promotion was for an unheard of brand called DCA which is from .. China! Well for the limited used that it will see I think it should be fine. At around USD75 its not too expensive.

I got home and hooked up the e-wrench, on the second press of the trigger the nut unscrewed right off! Next was the crankshaft gear nut.. one more press of the trigger and it came off (left-handed nut). Should have gotten one earlier, would have made life easier when doing the brakes on the MB!


Here's a pic of the right side of the engine with both the clutch hub and crankshaft nuts removed.

I tried rocking the clutch shaft, not much where present. That sound is basically the front sprocket moving the drive chain and taking up slack.

And this is the tool I bought. Not bad at USD75.

Next is to get the stuff on the left-hand side of the engine off. Flywheel, contact-point/coil plate, gearshift stuff, front sprocket (another opportunity to use my new tool!) before I drop the engine to get deeper.

Trying to solve the engine rattle.

Well I've finally decided that the engine is too noisy and that I need to take a closer look at whats going on inside.

Since the engine was running I started it to warm up the oil before draining it. Theres not much oil.. about 500ml is what it takes.

Next job is to remove the footrest, you need to remove the 14mm bolt (which has a 14mm nut on the other end) and 12mm bolt which bolts in the body. Yamaha conveniently mounted the main stand on the body so you can still work on the bike without resorting to other methods to keep the bike upright. Once the foot rests have been removed, you need to either remove the exhaust or remove the right footpeg rubber. I decided to remove the exhaust as its simple enough.

I then removed the outer cover, this reveals the carb, clutch actuator and two-stroke pump. These are easy enough to remove. The hose needs to be pulled out of the oil-pump and withdrawn from the airfilter base. a bit of oil will come out, raise the end of the hose higher that the 2T tank (or oil level in the tank and the oil will not flow. I secured it to the oil-tank knob with a zip-tie.

Once that is done I removed the inner cover, bit of oil will leak out so have some newspaper handy. This will reveal the clutch. There are six bolts .. remove these evenly with a 10mm wrench. You will notice some rubber spacers between the clutch plates, these can be gently peeled off. Next you will find a 20mm nut which holds the clutch hub to its shaft. This is where I get stuck. On most bikes you will hold the clutch basket with a simple tool but here you need to hold the hub stationary while turning the bolt. I can get the hub to stay in place by putting the bike in gear and jamming the rear wheel but these bikes are lightly built and there is a strong possibility of breaking something. I probably need to make a holder which bolts onto the six screw-posts in the hub. Anyway I'll stop here and check around before I break something.

Here's some pictures of the clutch basket and hub.

Stay tuned!