Very low compression

[96Zx600]

I went to ride my bike the other day (1996 ZX600C) and noticed it was acting very weird. Without being choked a little bit it would eventually sputter out at lights. As soon as I gave it throttle thought it was fine and pulled like it always had. Couldnt find a problem with fuel or spark so I did a compression check. I got 65, 45, 45, 45 on cylinders 1-4 respectively on a warm engine. I upon seeing that I was shocked it was even running. Wet compression yielded almost no difference. Before this it was running great and pulled almost 30mpg last fill up.

So on to the reason for this post. This bike was not very well maintained before I had picked it up. It has 27k on it and I doubt it has ever had the valves adjusted. My question is if the valves are not set up right and thus not sealing, could this be the cause for such low compression numbers? Leakdown test is coming, but I just havent had time for it yet. Any guidance is appreciated. Thanks.

[Gary - K7GLD]

YOU guessed it - the valves need adjusting - BAD!

Keep riding it the way it is, and you will likely be in deep trouble - soon!

[96Zx600]

Yeah I havent ridden it since it started acting up. Im still planning on doing the leakdown test, but Im glad to hear I am on the right track with the valves. Hopefully nothing is to far gone in it since it was running great just a week or two ago. Is there anything else I should check out while I am doing the valves?

[96Zx600]

Also, does anyone have or know where I can get the specs for the valve clearances? I dont have a FSM and dont see anything in my repair manual. Thanks again.

[MFolks]

Manuals (Some of these websites sell used manuals, just ask)
Repair Manual | Owners Manual | Haynes Repair Manual | RepairManual.com
ManualsNMore.com: Factory Service Motorcycle & Auto Repair Manuals
http://www.midwestmanuals.com/
Books4Cars.com - Every Repair Manual, Service Manual, Owners Manual and Book for your Car, Truck and Motorcycle
RepairManualClub Download Area
Motorcycles maluals
Vintage and classic motorcycle manuals and literature

[96Zx600]

Well finally got the valve cover off to check the specs. That thing is a ***** and a half to get off. I was shocked at the clearance, or lack there of on my valves. Intake was <.038mm across the board while exhaust was .127mm on all except #3 which I was just barely able to get the .152mm gauge in. Needless to say This was what was causing my horrible compression. I have one question about adjusting the valves though. What do you use to turn the adjustment screw? It looks to be a square head about 2.5-3mm in size. I dont have any wrench or socket to turn it and there is no slot for a screwdriver or anything. Thanks for the help.

[MFolks]

Pictures? We(that is the forum members) can probably advise, if we have an idea of what the adjustment screws look like.

[96Zx600]

Here ya go.

[MFolks]

Maybe a 3 or 4mm open end wrench for the square screw head, and possibly a 10 or 12mm wrench for the hex jam nut(it could be a 13mm too).

[96Zx600]

Jam nut is no prob, its the head of the adjustment screw I was looking for. I guess Ill just measure it with a caliper and head over to sears to see if they have anything that small.

[96Zx600]

Sears didnt have anything small enough and there is not enough room for an adjustable. Anyone have any ideas?

[MFolks]

Contact Z1 Enterprises, Inc. - Quality New Parts for Vintage Japanese Street Motorcycles and ask if they have a source for special Kawasaki tools. Also if you have a Snap-On or Mac tool supplier in your area, they might have or can order a small open end wrench that will fit the square head of the adjustment screw. Maybe a 1/4" drive deep socket with a square opening will fit.

Call the Kawasaki dealer, they should be able to tell you what tool is needed(and maybe can get it for you.....

[96Zx600]

Thanks for the info. I just figured out something to make it work. Its not the fastest, but I used a pair of needle nose pliers to break the screw free and then I can spin it with my fingers. Ive only done the outside cylinders so far so if the inside ones are an issue I might give them a call tomorrow after trying that socket trick. Thanks again.

[MFolks]

These forums can usually come up with solutions to problems, so don't give up, someone has been in your situation before.......

[96Zx600]

Just finished adjusting the valves. Man is that a pain. I did a quick leakdown check with the cover off to check and make sure things were sealing better. Tried number 1 and it didnt hear any hissing from the intake or exhaust. I tried 4 next, but when I did the engine rotated from the air pressure. I was only using ~60psi to check, but the piston will not stay at TDC in number 4. It either rotates a little forward or back depending on whether the piston is a hair before or after TDC. Ive never had that happen before from a leakdown test. What would cause that?

[MFolks]

Tried pulling the sparkplugs for the other cylinders? Or rotate the engine a few times before trying the leak down test?