81 Maxim xj650 shifting problem

I own an 81 Maxim XJ650 and love the bike. Bobber project in the making. But I've recently lost 2nd-5th. Lately 2nd & 3rd seem to have been slipping at higher RPM's (around 5-6000) and it had me in interest. Now i cannot shift past first at all. It feels stiff trying to shift from 1st to second as if someone has hammered a chisel between gears. I've read through a few forums on here and a few similar problems have occurred with other owners. I've taking the right steps in flushing out the system, pulling the cover and checking for any dirt, dust or metal particles that could have possibly wedged their way into the gears. But to my surprise their is no such issue. I'm at a dead end on thoughts and would like some input on what else it may be. I'm the front-man of Michigan based band "Underground Fight Club" and don't have alot of free time to tinker around to find the issue between recording and touring. If anyone knows anymore about this issue please ask me any question to help diagnose this issue

 

Let's do the easy stuff first.
What oil are you using?

 

10-40 fully synthetic amsoil. I've got it diagnosed down to being the shifting fork possibly.

 

1. Should using regular dinosaur oil

2. Sounds like your chain guide is breaking up, even if you don't see the pieces caught anywhere. Read up on the guidectomy again, just to make sure---

3. Yes, it could be bent shifter forks though---

 

Is their a chain inside the gear casing? The 81's are shaft driven bikes and I haven't seen signs of chains unless it's in the bottom end. Today I'll be flipping the bike upside down and pulling the oil pan from the bottom and taking a look at what's going on in there. It's either that or pull the motor and crack the case witch is rather not do. More updates to come.

 

There are two chains inside:

Starter chain, and timing chain. Your symptoms are very much in keeping with the primary chain guide breaking up.

If you remove the left shifter cover, you can take a look, and retrieve offending pieces. It's a temporary fix, but get you shifting again til you can do the proper repairs. Here's a link:
http://www.xjcd.org/emergency_guidectomy

 

I think Hogfiddles made a typo. The chain guide the breaks up (most often) is for the starter chain, which is the primary chain guide.
When mine broke up I cleared the chunks, and later found a big piece on top of the gears, which was causing me to miss the shift into second occasionally. I also found a half-chewed-up oil nozzle, caused by the chain slapping into it (which is why clearing the detritus alone is only a temporary fix).

 

Typo corrected

 

As was mine. I typed "tyop" three times before I got it right.

 

Lol!! Spit my coffee out on that one!!!

 

So I've got the bike flipped upside down like a bicycle, oil oan off and gears exposed. Theirs no cracks, fractures or chunks of metal or rubber anywhere to be found. But I did see on some build up on the shift cam where, I'd have to say the dog ears, slide around it letting it smoothly shift through the gears. Something must have been locking the gears from sliding since now I've got it upside down all 5 gears shift properly.

 

The chain guide is on the upper case. When you flipped the bike the bit of guide that is likely the problem would have fallen back onto the top of the case, and out of the way. You may be able to find it with a good flashlight and a bit of wire to poke around with. Carefully removing the oil pump will give you more room to work. Have a look at the oil nozzle that resides just above and slightly to the rear of the oil pump. If it looks chewed up then you may not have much riding time left before you absolutely have to spilt the cases.