oil in exhaust pipes-rings

Must remove valve cover for access to cam lobes where clearance is measured with a feeler gauge between low side of lobe and bucket atop valve stem.

On a KZ650 "measuring" clearances is the easy part, and all the clearances may be just fine, with no adjustment being needed. Especially where the engine performance and compression is already acceptable. Many KZ650's run a long time without needing any valve clearance adjustments. But the clearances should be checked (measured) per the routine maintenance schedule.

Typically, wear causes the valve clearances to gradually tighten, until eventually a thinner shim is needed to afford the factory specified clearance (gap).

However, as and when adjustment eventually becomes necessary, that's the more difficult procedure where the shim underneath the bucket is exchanged for a different size, which requires removing the cam shaft in order to lift the bucket and get to the shim.

Please do not attempt cam removal, etc. without studying, understanding and following instructions in the official Factory Service Mauual. Otherwise, expen$ive mistakes may me made.

Good Luck!

Thanks Patton, I was reading in my Clymer manual about some of that stuff,
Clymer is a little vauge about that procedure:blink: . I need too get a KZ
manual. Thanks for the heads-up.

TODDSTER wrote:

Also forgot to ask. What is a valve lap? Thanks in advance.

Cold compression test first, then squirt a little oil into the spark plug holes to seal the rings and retest. It tells about the ring/cylinder wear if there is a big change.

Valve lap is cutting the valves and valve seats to get a good seal. If you are going to put in new seals, lapping the valves is very little extra work in the process.

Are the spark plugs oil-baked or sooty(rich condition)? If oil is coming from the engine, it might not all be washed off the plugs, and cause fouling, or build up from being baked on the plugs, and piston tops, and combustion chamber. What type of oil are you using?

You gotta know the valve clearances are within specs, or the compression test will not be that accurate.

Why a cold, not a hot compression test, both dry then wet with throttle wide open? What would the cold show that the hot wouldn't?
Side Note: Cold starting issues usually tend to be a lean condition, and hot starting issues tend to be a rich condition.

I just recently did a compression test on a used engine(13,000 miles) hot dry, then hot wet with the throttle wide open and got about 15 psi difference in the dry and wet, but till had low compression in one cylinder(not changing wiht adding the oil). Make sure the battery is at a full state of charge during compression testing. Checked the valve clearances, and an intake was tight, too tight for the smallest of any of my feeler gauges to slide between. I replaced the shims needed in all to get them within specs, and the rest is history. This was a used engine, and was running fine before the test, but I could feel something wasn't right in acceleration. From now on, I check compression on a warm engine, and then check clearances after. It's easier that way.

Age and valve seals, well we know which one loses every time.

Plugs have a nice light greyish color. They don't seem to be filed. I'm using
10w/30 Kawi oil. I'll try the compression test both ways. What the heck, I'v got nothing to lose.:woohoo: Your logic makes sense, but regardless of outcome.
I've got to figure this out & I,m open to all suggestions, theories, & hypothesies.
Thanks for all the imput from all who contributed, thats what makes this such a
great site. The amount of imput & concern from fellow kz'ers, well it makes me feel warm and fuzzy all over.:laugh::laugh::laugh: :woohoo: Thanks Again

MFolks, bountyhunter,Patton & Beat poet. Comp. test on my kz650 D1A sr with motor at op. temp. are as follows
#1-135 lbs
#2-140 lbs
#3-140 lbs
#4-150 lbs
#1 plug was fuzzy sooty blk. What do yall think. :huh: Didn't get to the wet comp. test yet, maybe later today or tonite. 15 lbs of seperation=10% ??? Let me know what your thoughts about this might be. Thanks TODDster

TODDSTER wrote:

... Comp. test on my kz650 D1A sr with motor at op. temp. are as follows
#1-135 lbs
#2-140 lbs
#3-140 lbs
#4-150 lbs
#1 plug was fuzzy sooty blk. What do yall think. :huh: Didn't get to the wet comp. test yet, maybe later today or tonite. 15 lbs of seperation=10% ??? Let me know what your thoughts about this might be. Thanks TODDster

Imo compression figures are acceptable.

Sooty #1 plug might be from weak spark with perfect fuel mixture, or ample spark with excessively rich fuel mixture (due to whatever reason), or both.

Would replace #1 plug with brand new NGKB8ES (or whatever factory specifies -- might be the one step hotter NGKB7ES???) Never go more than one size hotter than standard plug. Sometimes the one step hotter plug is an approved alternative where extended low rpm plonking around city riding is causing the plugs to load up (without an occasional high rpm blast to help keep them clean). But should do all the following checks first before resorting to a hotter plug.

Assure good battery, fully charged, with clean tight terminal connections, and a good ground connection where negative cable attaches to engine or frame.

Are plug wires old, hard, worn-out and leaking voltage (30 years old)? Are plug caps faulty? Would at least measure ohms on secondary loop winding. (Measure from cap to cap, then remove caps and repeat from wire end to wire end.) Expect high ohms, such as 10-20K (refer to manual for specs). May test for leakage by running engine in a dark garage while spraying water mist over plug wires and watching for sparks where voltage might be arcing to ground.

If not already done, may be time to consider new green Dyna coils and Dyna solid core plug wires (from Z1E of course).

If not already done, would also assure correct service fuel level using the clear tube test method. A too high fuel level can result in excessively rich mixture with otherwise perfect carbs.

Could also experiment by leaning out the pilot circuit -- turn side located pilot air screw out counter-clockwise 1/4 turn and see it makes any difference.

Finally, could resort to addressing carb internals with emphasis on attaining a perfect as-new pilot circuit (both air and fuel passages, and pilot jet).

Good Luck!

Are the valve clearances within specs as well? Check that before going any further, with the a cold engine.

Oil seeping down a vavle seal will normally result in smoke on start ups.

Usually the factory recommends rebuild when compression is 14% or greater difference between cylinders.

the compression seems ok,, since the plugs are not oil fouled I dont think there is a ring problem.
I am thinking a valve cover leak, tach cable leak, something along those lines.
does the bike seem to somke out the exhaust at all?

Hey Patton, Corey, & BSKZ650 thanks 4 the replys & suggestions. Coils & wires are original. PO said after 1st service(dealer) he did his own maintenance. Don't know. Said he had carbs cleaned,speced,& synced. She sure shoots & scoots so I think he did those things like he said. Not sure what clear tube test is. I take it your referring to carberation? I'm thinking valve burnt or no seat or not closing completly due to carbon build-up or spring or some such nonsense. But then what do I know, thats why I'm typing here. As for the Dyna wires & coils they'll have t$$ wait. Dollars are tight like she(bike)used to be.:woohoo: Cleaned & regapped all plugs & got one on list for replacement. Haven't checked timing yet, but if its out its only a wee wee bit.:blush: Depending on bat. grnd. coils & wires I may go to a warmer plug on #1. Turn out pilot air screw on #1 dirty sooty bitch.:ohmy: Yea good idea. Haven't checked valve clearances yet as I'm saving that for win.....ter. Thats hard to say at my age, what with every passing yr. & going deeper in debt.Cost of fuel. What with the economy being the...Oh,Oh yea phew,:blink: I'll ck. valves when I take her down this Win..r She smokes when I start her up. I'm startin to see a pattern here. I think I found the problem.:silly: Bwahaahaaha Should have got a male bike. No P.M.S. Well rambled to long. These things happen when ya start going up the steps fallin down. I think I'm "Nucken Futs". Later ya bunch a krazy kz'ers & thanks....for puttin up with my sanity...LAter;)

If you replace the seals, be sure to replace the guides as well. It's always best, that if you remove the head, and you have a lot of miles, do a top-end rebuild. Save you alot of time and money, to do it right the first time.

Thats what i'm gonna do Royal1MC. I don,t think i'm gonna get to many more rides this season. Just got back from 35 mile ride with my brother, 34 degrees & 25 mph winds burr. Your right i'll just start gettin things together & tear the top end down & redo the whole shootin match. my self adjusting cam chain tensioner doesn't work anyway & with it blowin oil, its time to do major surgery. I just need to get the parts together, make a list & get them on the way. Not lookin forward to working in a cold 12 x 16 shed(no garage). oh well. It smokes when I start it. Seems to be loosin hp & zipp, Maybe carberation problems also. Ya gotta love it or you'll cry & that don't solve nutin. Thanks for the advice & all you others who chimed in. I'm out!!!