stock 1981 kz550 - running lean lean lean

Yeah, it's so counter intuitive, it gets a lot of people.

As far as adjusting the valve lash, it's one of those things that takes a lot of time the first time or two, but after a few times you know the tricks and procedure well enough that it just gets routine.

A big part of it is having just the right tools. It doesn't take any special tools, but just the right combination of nut drivers, screwdrivers etc.

The first time will eat up a day, though, but most of that is cleaning gasket material.

The big thing to remember is to dig out every last bit of sealant from every bolt hole. It's weird how silicone in the hole makes it so easy to strip out a hole. It lubricates so you just can't feel the torque, and the silicone will not compress much (similar to a liquid) so the bolt just cleanly removes the threads in the head, just about the time you say say to yourself, "hmm this feels strange".

loudhvx wrote: Yeah, it's so counter intuitive, it gets a lot of people.

As far as adjusting the valve lash, it's one of those things that takes a lot of time the first time or two, but after a few times you know the tricks and procedure well enough that it just gets routine.

A big part of it is having just the right tools. It doesn't take any special tools, but just the right combination of nut drivers, screwdrivers etc.

The first time will eat up a day, though, but most of that is cleaning gasket material.

The big thing to remember is to dig out every last bit of sealant from every bolt hole. It's weird how silicone in the hole makes it so easy to strip out a hole. It lubricates so you just can't feel the torque, and the silicone will not compress much (similar to a liquid) so the bolt just cleanly removes the threads in the head, just about the time you say say to yourself, "hmm this feels strange".

Dang that is good to know. That silicone is a gotcha. I'm glad you posted that -- this backyard mechanic stuff on my part is looking like there is a lot more wisdom that you'd expect. I've run across a few stripped holes in the top end, this was a late-70s Kz1000, I always thought 'the guy who did this was a sloppy mechanic' -- I would now ask forgiveness for that accusation -- I can easily see myself allowing sealant to help me strip the threads of the camshaft caps like this prior owner did. Thank you for the benefit of your experience.

Okay, I pieced it all back together -- I started this thread thinking I had a carb problem due to the lean running, had no idea it was a carb problem yet a completely different one.

The bike makes no more noise, not at idle, not off idle, it's fine.

I very carefully inspected the valve cover bolts to see *any* sign that maybe someone in the past pulled the valve cover then forced it back on, forgetting to do the cam chain tensioner cap removal. I wanted to 100% eliminate the cam chain being the source of noise. There was absolutely no sign of the valve cover bolts ever being wrenched on. The valve cover bolts also have a Phillips screw head, and no sign of a screwdriver ever being used on any of them.

At 14,000 miles, I don't think this bike has ever had its valve cover off. So the cam chain was never the source of the mechanical noise -- it was the primary chain I'm going to assume.

I learned a real critical lesson here. For my style I prefer hands on experience rather than reading about possible causes -- this was a great opportunity to see and hear the profound effect of carb sync. This lesson is far more memorable than any troubleshooting list, it was like a lab experiment.

Thanks to everyone for your patience and expertise -- the bike is 'normal' now. It runs great.

Good to hear.
But, yes but, I really believe you should check the valve clearance. I believe the stock valve cover hold down bolts will have a 10mm hex nut, no Phillips. You can cut a gasket, I do.
PM sent.

If your compression numbers are good after a long hot ride, then dont sweat it.

You will feel a difference/loss of power in the engine many miles before you will have the massive performance issues caused by a valve starting to burn up with no clearance.

Although... I believe 14000 miles is almost 3 times past due for clearance checks :whistle:

You never said..., did you use the Morgan unit and sync everything?

Doesn't take long to Check, and then you know. Look at the recommended service interval from KAW.

TeK9iNe wrote: If your compression numbers are good after a long hot ride, then dont sweat it.

You will feel a difference/loss of power in the engine many miles before you will have the massive performance issues caused by a valve starting to burn up with no clearance.

Although... I believe 14000 miles is almost 3 times past due for clearance checks :whistle:

You never said..., did you use the Morgan unit and sync everything?

I was going to bust out the Morgan but man oh man the bike is so radically better I doubt it would change much, however I may do it still, but first -- this has been a long week of wrenching and I am looking fwd to a bit of riding it for now!

Let me tell you the changes. First, when I start it, it seems to start and get to ambient running in a lot less time -- and I have set the idle low, just below 1000rpm, that is the payoff, at least for me, because at that low idle it just purrs man. I was ashamed to ride the thing before, it made so much noise like 'that guy must be poor, he cant afford a good ride', just embarrassing. It's like pulling up to a stoplight in a smash-up derby car. They feel sorry for you, no question. No one likes being embarrassed like that.

I'm having fun riding it. It makes a cool jet-like sound, probably the stock intake setup that I'm hearing, it sounds cool and has lots of power.

Inside the carbs, there was yellow dots of paint that the Kaw factory must have dabbed on to the throttle slide adjustment screws/nuts. On carbs 1, 2 and 4, those paint dabs cross the top of the threading adjuster screw and over onto the stop-nut so you can tell if the slides have been messed with.

Until I disassembled slide linkage on #3 carb, the yellow paint was *unbroken*, it was clear no adjustment had ever been made.

So it was real easy to re-align that #3 carb -- the spaghetti gauge system initially had carbs 1, 2 and 4 all lined up so I just brought #3's adjustment to match. I'm sure the Morgan will fine tune it, but after being down for a week you just have put on your riding hat and enjoy the outcome of your efforts.

I did see the valve clearance check is overdue per the manual, I will get to it, I suspect from looking at the fasteners it's never been done.

I didn't read the entire post, but if the sound was sort of a knocking noise down low, louder when it was colder or at lower idle, then yes it's probably the primary chain. All of the 550's seem to do this, at least every one I've dealt with. Some are louder than others. But it usually should go away completely if you can get the idle smooth at around 1300 to 1400 rpm after it's warmed up.

I've seen some 550 valve cover bolts that were just hex and some that were hex with a philips cross in the head. Kaw may have changed from one type to the other at some point.

At 14,000 I would expect to have to do a valve clearance check, but maybe not quite a shim swap. The 550's mostly came with 2.50, 2.55, and 2.60 shims when new. There may be an odd 2.45 thrown in there. You can use the same shims as 650s and 750-fours.

Here's how you know when you need a Valve clearance check.
If the bike rides fine and idles fine on normal to hot days, then there is at least enough clearance to run at normal temps.
To check high-temp conditions: Ride the bike on a warm day at a sustained 65 to 70 mph for at least 15 to 20 minutes, then take an off ramp and come to a stop and see if the bike stalls.
If it just idles fine as if everything is fine, then I wouldn't bother checking the valves.
If it stalls but will restart fine, and run ok as long as you keep moving, but has a really rough idle for a few minutes till it cools down slightly, then runs and idles fine after about 5 or 10 minutes, it's likely a valve lash issue. (Don't ride the bike on the highway any more until you do a clearance check/adjustment.) That's the classic valve-lash-too-small early symptom.

If the lash is really bad, any hot day will let it idle fine until it warms up, then the bike will like to stall on you. The hotter it gets, the worse it gets.

The best part is you check it by riding the bike.

If it comes time to adjust the valves, I have a page for the camshaft info on 550's:

home.comcast.net/~loudgpz/GPZweb/CamsKZZ...KZZXZR550500400.html

I also have a lot of other 550/Tk-22 info on that site.
I hope to have a few pages dedicated to the tk-22 carb info specifically.

BTW, one of my 550's make that jet engine whining noise too. i don't know what it is, but it sounds cool. Sounds like it's coming from the alternator area, and it's done it for years.

loudhvx wrote: If it comes time to adjust the valves, I have a page for the camshaft info on 550's:

home.comcast.net/~loudgpz/GPZweb/CamsKZZ...KZZXZR550500400.html

I also have a lot of other 550/Tk-22 info on that site.
I hope to have a few pages dedicated to the tk-22 carb info specifically.

BTW, one of my 550's make that jet engine whining noise too. i don't know what it is, but it sounds cool. Sounds like it's coming from the alternator area, and it's done it for years.

Thanks for the heads up on the 'early warning' sign for the valve adjust -- it's funny, I'm 51 now and been riding street bikes since 1976, I have in fact had the exact experience on some of my rides -- pull off the freeway and the bike stalls then is hard to start. Now I know why. Thanks for that tip and the link.

That jet-like turbine wind-up sound is a 100% trip -- I chalked it up to the fact that the bike is all stock and in great condition, and figured the intake noise sounded like that on all of them, wherever it's from, it's really distinctive. For those of you who've never ridden a vintage Kz550, it sorta sounds like when you're inside a turbocharged road car and the turbo is winding up -- really a rush. Mad Max's V8 Interceptor in Road Warrior is also a close match, think that was his supercharger.