KZ440 LTD... Help! White smoke, oil on spark plug

Okay, i'm new here and new to bikes so i'll try not to be a total newb.

Background - Bought and 82 KZ440 LTD with only 6400 original miles for $300 bucks. I got it from an estate sale so who knows how long the bike sat.

Since purchasing - I've taken the carbs apart and cleaned, changed oil (20w-50 API SF), replaced oil filter, clutch cable, battery, spark plugs (NGK B7ES gap .030)

After doing the carbs the bike would idle fine and seemed to run well (not great)

After changing the oil I noticed that the left exhaust pipe had white smoke and seemed to have a misfire. I checked the plugs and noticed the plug had oil on the tip. I put a new plug in, fired it up, and as soon as an throttle was given it started with the smoke and misfire.

I took the plug out and noticed oil on the plug. I did do a compression test PRIOR to changing the oil and PRIOR to this problem and both cyclinders were 120psi

WHAT IS THE PROBLEM??? Any advice? Is it the valve steam seal?

Why 20w-50 ?

82KZ440*801 wrote:

I took the plug out and noticed oil on the plug.
WHAT IS THE PROBLEM??? Any advice? Is it the valve steam seal?

The valve stem seals are notorious for causing this. They do on my 750 twin, exactly as you said. Oil runs down through the open valve after you shut off the engine and coats the plug.

(NGK B7ES gap .030)

The 750 twins run the hotter B6ES. That can help if you are oil fouling plugs which is what yours sounds like.

I did do a compression test PRIOR to changing the oil and PRIOR to this problem and both cyclinders were 120psi

If that is hot reading, I think it is right on the service limit. My twin has standard compression of about 155. Sounds like yours needs a valve job maybe, or at least valves adjusted.

Well, I did 20w-50 cause that is what the Clymer manual recommended (again, this is new to me, I am more familiar with cars)

And how hard is it to change out the stem seals? The Clymer manual (which is horrible) makes it seem like a huge involved process. What would the cost be associated to a repair of this nature?

Also, when I first start the bike, it does take more choke to get it going. Initially the bike seems fine, but as soon as your remove some choke and give any throttle it immediatly starts with the white smoke and "puttering" (misfire) only in the left cylinder. Also, the smoke really isn't terribly bad at idle (it just idles really rough, barely idles) but as soon as you give it any throttle you can see it come out.

Is there anything else that could be causing this that is less expensive and less involved I.E. bad air filter, valve clearances needing adjustment?

I have never done a valve job, but really it's all nuts and bolts ( with a good manual i'm sure I could figure it out)

Also, in regards to compression - The manual has a range of 156- 109 being the limit, so I figured they were a bit tired but not terrible.. am I wrong?

Also, I have not adjusted the valve clearence yet since i've owned it, so again, bike has 6400 miles and who knows how long it sat, and when they were last done.

Could sitting for a long time cause the seals to go bad? I figured with the low miles, the motor should hopefully be in good shape. Previous owner worked for Kawasaki but passed away (not on the bike) hence the estated sale

what is your altitude the higher up you go the less air there is available to compress roughly 3.5% less per thousand feet of elevation increase so if your at 10'000 for example you would have about 35%less air to compress then at sea level. there folks is my lesson for the day. thanks for coming out and playing

Well, i'm in SLC UT so I believe it's 6,000 ft or so.

The only thing that changed that made it go from running and idling smooth to idling rough with white smoke was an oil change. I put in 3qt cause I also changed the filter. Is it possible that the oil on the spark plugs and white smoke is due to over filling the oil?

Maybe a combination of valves needing adjusting, dirty (old) air filter, to much oil?

with the old oil (not sure how old) there was no issue as far as smoke and oil on plugs, in fact, the motor was running lean do to the carbs not being secure with the air box, and broken exhaust studs (which is now resolved) there was white on the firing tip of the old plugs.

do your eyes water if it runs for awhile. by the way this is a serious question.and if your at 6000 ft. your compression numbers will be lower by almost 20% than at sea level.

82KZ440*801 wrote:

Well, I did 20w-50 cause that is what the Clymer manual recommended (again, this is new to me, I am more familiar with cars)

And how hard is it to change out the stem seals? The Clymer manual (which is horrible) makes it seem like a huge involved process. What would the cost be associated to a repair of this nature?

If you pull the haed and carry it to the machine shop, a valve lap and new seals would be about $200.

82KZ440*801 wrote:

I have never done a valve job, but really it's all nuts and bolts ( with a good manual i'm sure I could figure it out)

With a good manual, it's doable.

82KZ440*801 wrote:

Could sitting for a long time cause the seals to go bad?

They are rubber. Old rubber = bad news.

82KZ440*801 wrote:

Well, i'm in SLC UT so I believe it's 6,000 ft or so.

The only thing that changed that made it go from running and idling smooth to idling rough with white smoke was an oil change. I put in 3qt cause I also changed the filter. Is it possible that the oil on the spark plugs and white smoke is due to over filling the oil?.

Did you check the oil level?

timebomb33 wrote:

do your eyes water if it runs for awhile. by the way this is a serious question.and if your at 6000 ft. your compression numbers will be lower by almost 20% than at sea level.

Interesting. That would drop nominal from 155 down to maybe 125. I guess 120 would be OK.