Kz650 valve stem seal replacement

So i have some white smoke coming from my kz650 B3's left exhaust. From what i have researched and my mechanic has told me, it seems the valve stem seals might need replacing(2hrs @ 69.95hr) or worse, the valve stem guides might be worn(7hrs @ 69.95hr). I have also found that this is a common problem on bikes that have been completly rebuilt? My kz was by the previous owner, though mechanic said was in "excellent condition besides leak." Anyone else have this issue?
The bike only has ~10,000 miles on it so im hoping its not the guides..
Maybe needs viton stem seals?
Compression check showed
#1-114 #2-110 #3-110 #4-111

Left spark plug, how i got it. Right spark plug, after ~100miles.



Also what level do you rate changing valve stem seals as far as DIY?
This is my first bike and never worked on a motorcycle before except changed oil and spark plug . I am quite handy and have found some people using the "rope trick" so they do not have to take off the head. What tools would i need? Valve keeper? www.amazon.com/gp/aw/d/B0012S61IO/ref=mp...22554&sr=8-2&pi=SL75

If I needed valve seals replaced and could get it done my a competent mechanic for $140 labor charge I would pay to have it done. To me, that seems like a very reasonable labor charge for that job. Ed

Amen, $140 labor for that is a steal. He might be going to do it without pulling the head.... cotton rope stuffed in the spark plug hole to keep the valve up while he takes off the keeper/spring/seal.

Be sure to get VITON seals. The butyl rubber seals do fail, my bike is on it's third set (seem to last about ten years). Vitons are much better.

FYI: I bought a set of valve guides to use when I did my rebuild at 75k miles and the guides all measured like new. Still have the new guides available at a discount.....

Yeah if they will be able to actually replace all the seals in 2 hrs from start/finish Id pay to buy a ticket and watch these guys work.

wireman wrote: Yeah if they will be able to actually replace all the seals in 2 hrs from start/finish Id pay to buy a ticket and watch these guys work.

Good point; they should make a video.

sounds like a "quick and dirty" with no head removal. At $140 if he's r&r the head ,it's a steal.

I see your running ngk b-7 (hotter) to keep from oil fouling? :blink: . the 650 can use ngk b7es :evil: or ngk b8es (standard plug) like the big fours I thought :huh: .

Id say its a little tough to check guides without pulling head off

Thanks for the replies everyone. I do agree that it is a good price and will take it in as soon as I get the new seals.
I found these, should work.
item.mobileweb.ebay.com/viewitem?itemId=230759695057
So he really wouldnt be able tell if the guides are worn when he changes the seals?
I guess if the problem persists after the new seals are in then its probably the guides.

turboking wrote: sounds like a "quick and dirty" with no head removal. At $140 if he's r&r the head ,it's a steal.

I see your running ngk b-7 (hotter) to keep from oil fouling? :blink: . the 650 can use ngk b7es :evil: or ngk b8es (standard plug) like the big fours I thought :huh: .

They are the b7es.

gbot9000 wrote:

turboking wrote: sounds like a "quick and dirty" with no head removal. At $140 if he's r&r the head ,it's a steal.

I see your running ngk b-7 (hotter) to keep from oil fouling? :blink: . the 650 can use ngk b7es :evil: or ngk b8es (standard plug) like the big fours I thought :huh: .

They are the b7es.

B7ES is the correct heat range for normal riding. Ed

It never ceases to amaze me what people call a rebuilt motor.Or "gone through" A rebuilt motor should have a completely rebuild cylinder head including guides if needed.

The motor has not been "gone through" if the head has just been washed up and valves lapped.

Did you do the compression test with a fully charged battery and the throttle held open? What altitude are you at, because the higher you are the lower the #'s. If you did the above, and are under 6K', those #'s are to low. You may replace the valve stem seals and see no change. The problem is more a piston ring/ bore problem. If you are going to Do it yourself, you can do all the simple stuff. Leave the machine work to a qualified machine shop who knows bike heads/ cylinders. You first need the Factory Service Manual for your year and model. It will show you the tear down procedure, as well as all the specs for clearances. How to re-assemble, torque values etc. It will also tell you the Compression Limit, and how to do it.
The stem seals can be changed with the Head On, but you sound as per compression #'s and the plug reading that you need to look further.