1981 Kz650 running rough. looking for suggestions

Been working on my 1981 KZ560 for a few months now. It sat a couple winters in a heated garage without being winterized.

I took the carbs apart and cleaned them so far, replaced the spark plug wires, ran some sea foam through the engine.

Before replacing the wires it was bogging down after I rode for about 15 minutes to the point where it had zero torque. The new wires helped a bit but it just has no go. It revs super high as soon as I accelerate and has a real high pitched sound in it.

Is this just needing to rebuild the carbs entirely. I've never checked engine compression before so I'm not sure how that's sitting either. I recorded a few seconds and uploaded it to YouTube. If anyone has any suggestions it'd be much appreciated. I'm stumped

Also curious about the heating on the pipes. They've been blue for a long time and they all seem to heat evenly.

Thank you
Matt

Valves adjusted?
Steve

kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882

Haven't attempted that yet, found a decent overview of it here.
www.kzrider.com/forum/2-engine/600223-valve-adjustment
That should hopefully get me through it and I'll try to find it in my manual. Got a project for this evening now, thanks!

Before re-installing the valve cover. After checking the valves, remove the cap, cross wedge & spring from the auto tensioner, then re-install the cover. then lubricate the wedge & re-install the spring, wedge & cap.

Compression check. make sure the battery is good & fully charged. remove all 4 spark plugs. Install the compression tester into the #1 spark plug hole. hold the throttle grip at WOT. press & hold the start button until the pressure stops rising. about 5 or 6 seconds. note the highest reading. also notice how the needle pulses. then do the other 3 cylinders the same way. write down the numbers immediately after checking each cylinder.

Kawasaki service manual. jarlef z650. the 1981 KZ650 pdf is in the Files section.

so while checking the valves i just got the readings:
1 .005
2 .006
3 .006
4 .006
5 .008
6 .007
7 under .004
8 .010
Ive never done this before, does it seem correct?
I'm reading the manual as saying tolerances are between .08 and .018 so on the majority of them I'm not even there, does this call for replacing shims or is there any other way to adjust?

Also seeing a lot of fluid left in here. Does that seem normal or excessive?

compression test
1. 130
2. 137
3. 122
4. 135

usable range of 137-209 with 14 psi difference between any two cylinders... so thats low.. i did have the camshaft cover off still though, was that a mistake? giving me inaccurate readings or shouldn't matter?

Keep in mind, when checking compression.....

1. Engine must be up to normal operating temperature.
2. Battery must be fully charged.
3. All spark plugs must be removed.
4. Throttle must be held fully open
5. Crank starter until highest compression reading is reached.

Checking compression without those requirements being met can give bogus readings.

If compression is found to be low check valve clearances to ensure vales are closing all the way.

If a compression problem is suspected run a leak-down test to isolate compression leak since it may not be related to piston rings. Do this BEFORE removing cylinder head.

Ed

I'm reading the manual as saying tolerances are between .08 and .018 so on the majority of them I'm not even there, does this call for replacing shims or is there any other way to adjust?

If the figures above are in a HAYNES manual and are in mm then its probably a missprint. The Haynes manual for the 750 fours says valve clearance should be .08 to .018mm but it should read .08 to .18mm. I suspect yhe same missprint carried through to other manuals

On the other hand your readings for valve clearances look very much like inches. The equivalent spec in inches would be .003 to .007 i think but please double check.

Lots of oil in the cam area is a good thing

650ed wrote: Keep in mind, when checking compression.....

1. Engine must be up to normal operating temperature.
2. Battery must be fully charged.
3. All spark plugs must be removed.
4. Throttle must be held fully open
5. Crank starter until highest compression reading is reached.

Checking compression without those requirements being met can give bogus readings.

If compression is found to be low check valve clearances to ensure vales are closing all the way.

If a compression problem is suspected run a leak-down test to isolate compression leak since it may not be related to piston rings. Do this BEFORE removing cylinder head.

Ed

ah, engine was not up to normal operating temperature as I was checking valve clearance prior to the compression test.

JR wrote:

If the figures above are in a HAYNES manual and are in mm then its probably a missprint. The Haynes manual for the 750 fours says valve clearance should be .08 to .018mm but it should read .08 to .18mm. I suspect yhe same missprint carried through to other manuals

On the other hand your readings for valve clearances look very much like inches. The equivalent spec in inches would be .003 to .007 i think but please double check.

Lots of oil in the cam area is a good thing

Okay so converting it to mm gets me within spec on 1-6 but 7 is either barely in or under .08. my feeler gauge didnt go any smaller. 8 is around .254mm

Trumpology101 wrote: ...Ed ah, engine was not up to normal operating temperature as I was checking valve clearance prior to the compression test.

That could make a difference. When cold, the top of each piston is actually a little smaller in diameter than the bottom of each piston. The theory is that when the engine is at full operating temperature the piston tops are hotter than the piston bottoms and therefore expand a bit more than the bottoms. At that point that expansion should seat the piston rings properly in the cylinder bores. Below are a couple pics of stock KZ650 piston top and bottom measurements. Ed