Another "Head Gasket or Rings" Thread

Bike's been running perfect, perfect tan plugs, carbs synced yesterday, valves adjusted perfectly, awesome. While riding home on the freeway I exit and come to the stop light, notice white/blue smoke on the right side exhaust and I'm idling kinda high. Check the oil sight glass, little low, #3 plug is all oiled up but still fat blue spark. Here's what I've done.

Compression Test
Cold/Hot with wide open throttle 110/118
After tsp oil added 155
(All other cylinders other than #3 are between 110-120)

Leak Down Test (poor man's method)
Can hear/feel air coming out of oil filler but not out of valves/head

Upon start up, #3 header is slow to heat, slower than the others.

Faint smoke coming out of crankcase breather.

Of course my next question is, do I start pulling the top end off or what? Bike has over 50K on it and I'd hate to tear into it now because it's prime riding season but I don't see another choice.

One more note to add. The temp in Phoenix is mid 90's now and I added half a quart of 10w30 (moto oil) prior to setting out for that day.

Change the oil to something like 20-50 or a straight 30 wt then see what happens.

baldy110 wrote: Change the oil to something like 20-50 or a straight 30 wt then see what happens.

Are you thinking the oil is too thin and maybe slipping past the valve guides/rings? Just feeling for ideas.

When it leaks past the rings it goes to the bottom end out the crankcase vent or filler plug . Bad Valves, leakage comes out the valve cover . I think 30 wt is to thin for the summer 10/40 is fine (air cooled) . Those plugs are a little rich # 3 is black looks a little shinny (oil). Is this plug check at idle or a few mile ride ? When you run a motor rich with no exhaust rotator all you do is carbon the valve seat and when it gets hot it will pit the valve and seat . Then you need a valve job . Then you get a miss .

I idled the bike in my garage for a few minutes, took it around the block a few times and pulled the plugs.

Edit
So I did the poor man's leakdown test on the other cylinders and the #3 didn't sound any louder out of the filler tube than the others. I might add that it seems to only be smoking now under acceleration, not idle. Where is the oil coming from.....

Quick update
Changed to castrol jaso 20w50 with the same results. No metal shavings on drain plug, I even took my flexible magnet inside the drain plug and swept the pan, still no shavings. Swapped plugs around and #3 was oily again. Still slight bluish smoke on hard acceleration.

I have had engines in the past that smoked when the oil started breaking down. I would change the oil and the problem would go away. It sounds like it's time for a top end overhaul if all the cylinders are leaking. In a pinch and to make it till the season is over I have used 50wt Aeroshell aviation oil. It is really good stuff with all the additives needed for these air cooled engines. It is thick and will slow the oil consumption down the only downside is it's $$$.

The 20w50 was definitely thicker than the stuff I pulled out. The smoke was absolutely less. I know this is a shady shade tree thing to ask but... has anyone successfully used automotive ring seal in their engines. I imagine it wouldn't work well with the wet clutch but just thought I'd throw it out there.

BTW if anyone has any leads on where I can get a set of rings for the KZ1000E I'd appreciate. It doesn't appear Z1 or Schnitz has them. Thanks.

Any thoughts on possible valve stem seals leaking? It just seems that compression across the board is good enough to prevent this much oil burning.

quick question(s)...

Is it just carbon build up or is it gas or oil on the plug...?
Was this occurring pre-carb sync...?
Carb float settings to spec...?

How many turns on the pilots are you set at...?
Possibly carb idle/pilot circuits clogged etc...

Good spark on #3, possibly swap sparky cable/boot with #2 to see if it follows...

Just some thoughts pre-removing the engine...

Thanks for the reply. The #3 has an oily residue on it, does not smell like gas. This also did NOT happen prior to carb sync. On the way home from sync I opened it up on the freeway, took it up to around 100 for a bit and let off. This is when I noticed it, when I came to a stop at my off ramp.

Float settings are within spec, pilots are set at 1 1/4 with K&N Pods. It may be worthy noting that pre carb sync the #3 was furthest out on the mercury meter.

Spark on #3 is fat blue, even with oily residue on it. Like I said I have a hard time believing the rings/head gasket are bad considering compression across the board is 115-125 which I realize is slightly tired but should be enough? Also that #3 pipe is still slower than the others to warm.

I'm going to take it out today for a few miles and see what happens.

You can have good compression and still have leakage past the rings. Changing out the valve seals on a KZ1000 motor is not an easy task and if I was going to do that I would just tear the top end apart and re-ring it cause your into the engine anyway. Those mechanic in a can snake oils do not work.