So several months ago I began to notice that my clutch started slipping. At first it was just under extreme load, such as wide open throttle up a hill. I couldn't be real upset about it, the bike had over 33k miles on it and I am at least the third owner. I don't feel like I'm particularly hard on the clutch but who knows about the previous owners.
Knowing there was no chance of the problem going away I decided to look for options. I'm the kind of guy that, if there is a better than OEM part out there, I'm probably going to get it provided the cost is reasonable. I was somewhat disappointed, but not especially surprised to find that there aren't a whole lot of aftermarket clutch options for the 650. There were a few options, but most were plain organic discs and 5-10% stiffer springs. I finally came across KG Clutch Factory which offered kevlar friction discs and 20% stiffer springs. Naturally this costs a little more than OEM but not 2x more so why not? I figured that with the small power level of the 650, this would be the last clutch I would ever need.
I ordered the friction discs as a set and also ordered new steels from KG. Technically you don't have to replace the steels if they are flat, but I didn't know without tearing the bike apart so I decided to get new ones anyway. Looking at the exploded parts diagram there is ONE odd thickness steel plate that KG did not sell, so I ordered Yamaha OEM on that one as well as a Yamaha engine cover gasket. I got everything in months ago but didn't have time to replace it and I wanted to get the most out of my last oil change. I kept riding the bike with the clutch getting progressively worse. By the time 37k miles rolled around, I could make the clutch slip easily by going wide open throttle on level ground.
Finally, this weekend was the time to do it. I began by soaking the new friction discs in clean new oil.
I then drained the oil. Once empty I put the drain plug back and set about raising the bike on my motorcycle jack. It's a harbor freight piece which JUST doesn't quite work with my bike, at least not how I like it. The engine on the vstar hangs down ever so slightly below the frame rails so the jack lifts the engine instead of the frame, also making it wobbly on the jack. I made a wooden "adapter" plate to catch the frame rails and clear the engine.
Just because I'm not stupid, I put a strap around the bike to keep it on the jack.
My bike has Vance and Hines pipes, with the lower pipe being in the way of the engine cover. This had to come off, which required removal of the floorboard on that side. All of this is very straightforward, but may or may not be required on a bike with factory exhaust.
Once the exhaust was out of the way I could start removing the oil filter cover bolts. I've fought this battle before so I made a cardboard template that I could use to keep the bolts in their proper locations.
I did the same thing with the engine cover. After a little persuasion I was able to get the engine cover off and reveal the old clutch. Don't believe in synthetic oil? Look how clean this engine is. Ever since I've owned it, it has had nothing but Mobil 1 and later Amsoil.
To remove the old clutch I carefully remove the bolts in a criss-cross pattern, loosening them a little at a time to avoid potentially warping the pressure plate. I removed the entire stack of clutch discs and steels as a unit and set them aside. In this manner I would have a point of reference for re-installation should I somehow get confused about the order.
With the new components in hand I cleaned all of the steel discs with mineral spirits to remove any manufacturing / protective oils, and then carefully installed them along with the new friction discs. Once the whole stack was in place I put in the new springs and proceeded to carefully re-install the bolts. Again using a criss-cross pattern to avoid warping the pressure plate. Using an inch pound torque wrench I torqued them all to 70 inch pounds. (Actual spec is like 69.6).
Everything looks good, ready to go.
I tried the clutch lever and WOW was it out of adjustment. This lends credit to the idea that the factory clutch was fairly well worn. I adjusted the free play and made sure that it did seem to release.
Now the fun part, the &(*&(^*( gasket. I suppose I was lucky, the old hard factory gasket adhered 99% to the cover and only 1% to the block. It had hardened and was a royal pain to remove, but about an hour later with a razorblade, being exceptionally careful not to gouge the mating surface, I got it cleaned up.
Re-installation was a breeze because I had kept the bolts organized. The floorboard and exhaust went back on with no problems at all. With three quarts of fresh Amsoil 20w50 it was time to start it up. With the bike still in the air I verified that neutral did still work. I pulled the clutch and put it in first gear, and even with the clutch disengaged, the tire wanted to spin, but you could stop it with just a little bit of drag.
I shut it off and put it back on the ground. The lever feel was fantastic and the weight of the bike and myself provided enough friction to keep it from rolling in first gear with the clutch disengaged. The only trouble was that it was virtually impossible to find neutral with the engine running. I figured that this was simply because everything was new and very tight, combined with cold 20w50. I figured everything would loosen up after some riding but it was pouring down rain. I wasn't about to take my otherwise clean bike with a clutch that MIGHT not disengage out in the rain so I just packed it up for the day.
The next day the sun finally dried up all the water and it was time to take it for a spin. Neutral was still impossible to find, but it's just been sitting so I wasn't surprised. I decided to ride up to a little town about 20 miles up the road and see what happened. Even though I couldn't find neutral the lever pull was VERY good. Firmer than stock but not unbearable. The free play felt very good and there was no evidence of slippage, although I tried not to beat on it too hard for a few miles anyway.
When I got into town I pulled into a parking lot and was a little dismayed to find that I still couldn't quite find neutral easily. With everything up to full operating temperature I decided to beat on it a little. I took a different route home that allowed for some higher speeds. I ran through the gears a few times at wide open throttle and was happy to notice no slippage at all. At one point I took it up to about 90mph then chopped the throttle and clutched it for several seconds. I figured this maximum speed differential would help loosen everything up. When I got back to my town I was happy to see that I could again quite easily find neutral. Lever pull is still firm and progressive. Most importantly it is not at all "grabby." I didn't think it would be, but this is always a concern when changing to a more aggressive clutch.
Overall I'm very happy with it. Using basic hand tools and a few hours in my garage I was able to upgrade to a stronger clutch and total cost was less than it would have cost me to have a shop put in an OEM unit.
Here is a close up of the old discs. Notice the brownish discoloration on the outside edges? That's what happens when non synthetic oil (thanks previous owner) sits on a hot component. Overall though the discs just look worn, nothing burned or warped to indicate a major problem. Here's hoping for many more happy miles!