smoke from exhaust header

Silly me. I saw the hex head and assumed it unscrewed. If I have to pull the cam cover, I guess I should order a gasket. Is there anything else I should do while the cam cover is off?

That hex head is a confusing detail for sure. While you have the cover off you should check the valve clearances. They probably are fine as they rarely require adjustment, but they're simple to check and you won't need to pull the cover again for quite a while to check them if they are ok. I write down each of the valve clearance measurements in the back of my manual. I can then compare the previous readings to the current each time I check them to see if they have changed. Ed

Ok. I did order a Service Manual on CD. It's supposed to be 3-7 days delivery. I'll look for that procedure. Thanks again.

In your opinion, will I need any other gaskets other than the H shaped one for the cover? If I have to order parts again, I'd rather get everything at once.

You may want to pick up the gasket for the ignition cover (right side of engine near front). The ignition timing advance mechanism should be cleaned and lubed from time to time, and if the old gasket self destructs when removing the cover it would be good to already have one on hand. Also, the 90mm O-ring that goes on the oil filter cover would be good to have on hand. Some oil filters come with a new O-ring for the cover, but some don't. If that O-ring gets really old and flattened the oil filter cover can become difficult to remove. Ed

Mine was missing the fiber washer. And the Inner seal was a pain to get out. It's all together now. Didn't have time to fire it up though.

The whole 13091/ 13091A situation seems a bit like an engineering last minute fix. But I guess it works.

djturnz wrote: .....The whole 13091/ 13091A situation seems a bit like an engineering last minute fix. But I guess it works.

That 13091/ 13091A configuration baffles me too. Especially considering the earliest KZ650 models used a very simple "tachometer stopper plate" that works perfectly fine and is not so weird. Some engineer must have been bored and decided to re-invent the wheel. Here's a pic of mine and of the earliest KZ650 parts diagram which shows the part number. Ed

The photo you posted looks like a better system, simple because it's one piece. But it still seems like a hokey system. I can't believe my tac cable didn't even have that GEAR GASKET (cardboard washer) in there. The o-ring around the Guide housing looked great and the OIL SEAL looked pretty good too. It seems to me that there should be something between the gear and the guide at the spline end.

I'll confess I did booger up the threads on the guide for the tach cable, but ut still threaded on. The channel locks slipped. lol

Ed, thanks for all your help.

I have learned something today, the grief that those 2 parts 13090/13091 have given me on my 81 gpz is,heartbraking. I will order a 650 part and do away with those 2 pesky pieces of metal.

chirpy999 wrote: I have learned something today, the grief that those 2 parts 13090/13091 have given me on my 81 gpz is,heartbraking. I will order a 650 part and do away with those 2 pesky pieces of metal.

You may have a problem finding 13169-015. The only NOS one I was able to buy came from a parts place in Sweden. Ed

Ok so I've been putting off repairing this forever because the bike wasn't running. Now that it's running decently, i can't hear the engine over 40 mph so I don't know when to shift. Do I just need to replace the gaskets and seals in the engine or should I also buy a new tach cable?

I am having a similar problem with an 81 kz750.
I have smoke from the connection of the manifold to the pipe of number 1. I changed out the copper ring and it still smokes a grey smoke. The smoke is increased when revving. Any ideas are helpful.

Valve guide seals.
Steve