Puffing smoke - need an opinion

So the last time I had the bike out, it was getting a little cold around here and I noticed that my 82 650 started puffing white-ish smoke. Now that it’s 5 degrees, we have reached the perfect weather to start flingin wrenches outside so it’s time to dive in.

The compression checked out good so I reasoned (my wife laughs when I use that phrase in her presence) that the rings are sealing fine so the issue must be the valve seals. My plan, if you want to call it that, is to replace the valve seals without removing the heads. I’ve heard of an old trick of feeding a small diameter rope into the cylinder with the piston down, then rotate the engine slowly to hold the valve in place while you take the spring off and replace the seal.

My question is; am I barking up the wrong tree? Do these Kaw’s ever have an issue with valve seals or am I wasting my time? Should I be looking elsewhere like carburetion?

You can also keep the valves in place by pushing compressed air through the sparkplug hole. I've done this on a Chevy 350 while replacing seals. Ed

It quite posible its the seals, but if there gone ,the guides may be as well. How will u compress the springs??

mark1122 wrote:

It quite posible its the seals, but if there gone ,the guides may be as well. How will u compress the springs??

I couldn't figure that out either. You have to compress the springs and remove the keepwers and springs to get the seals out. I don't think there is a "top side only" compressor tool for these valves.

CSRchopper wrote:

Do these Kaw’s ever have an issue with valve seals

That's like asking if Rosie O'Donnel ever attacks the donut tray. My KZ750 is currently on it's third set of valve seals. Get VITON seals if you can find them, they last longer than butyl rubber.

Ironic this was brought up for I just have been reading & studying my shop manual for my final engine build in my project and recorded these notes....

Exhaust Smoke Colors: KZ900 Manual page 147...

NOTE: I realize you stated KZ650 but should be close to the same for T-shooting!

WHITE:
Piston Oil Ring Wear
Cylinder wear
Valve Guide wear
Engine Oil Too High!

BLACK:
Air Cleaner Clogged
Main Jet Too Large or Falling Off
Carb Starter Needle (Choke) Stuck
Float Level Too High

BROWN:
Main Jet Too Small
Intake Manifold Loose
Float Level Too Low

Also take a look at your spark plugs... Ceramic Insulator colors?

Are the carbs adjusted correctly, plugs may inform you if your running too rich...

OMR

Maybe I'm off base here, but the thought of trying to analyse exhaust color at 5 degrees is a waste of time. since no degrees is freezing and a natural by -product of combustion is water, doesn't it follow that white exhaust would be either steam or condensation? are you using oil? are you fouling plugs? the thought of tearing into a running engine without due cause leaves me a little....well cold. G

Somewhat true but I can't believe he'd (or anyone for that matter) even be out wrenching in 5 degree weather. Assuming he has it in a garage/cover of some sort.

As written as well, plug color... Don't even need to start it to check that...

Same time, unknown if this just started, only happens when cold, if goes away once warmed up, has been occurring for some time and now just getting to it etc...

He asked and we don't even know the color of the "SMOKE"...
Nor did he mention pinging noises... thus possibly bad rings... nor has he gotten to compression testings (low) for bad valve seats, sticking valve, guides/seals just as few to mention...

It can be one of many or multiple issues but to do nothing but wait for summer! What fun would that be...
Besides, at that temp, WTF else you going to do all winter...

OMR

OMR, Idle hands.... and a quick ADD, from no creditable source, just my own experiance, White exhaust, coolant, usually combined w/the obvious smell of burning etheline glycol.grey/blue,oil.common with piston/ring /guide/seal failure/wear, or buildup inside exhaust system from prolonged failure. black, fuel. stuck choke,leaking needle/seat, rich jetting, oil contaminated w/fuel,dead cyl. brown, I'm not intimate with, but high exhaust temps and combustion occuring in exhaust tract after the fact would logicly result in breaking loose old build-up. idle thoughts, G

when does it smoke when you start it,under power ,when you back off throttle?

coolant, usually combined w/the obvious smell of burning etheline glycol.grey/blue,oil.

...

Assuming this is a KZ900-1000, these are air cooled motors so not sure where the anti freeze is coming from...

Or am I totally missing something here...

OMR, YES.