compression problems?

I have an issue with my 1980 KZ1000 G1. It just doesn't seem to have the power I think it should. it's kind of balky until it gets really warm. It shouldn't be an issue, except this:

when I put new plugs in, it's really peppy for a day or two, then it settles back down to kind of sluggish.

Plugs in 1, 3, & 4 are a little oily. plug 2 looks good.

I checked the compression cold today and here is what I got: I checked each one 2x.

1: 145 to 150
2: 140 to 145
3: 150 both times
4: 150 to 160

then I put some oil in #2 and rechecked it and it increased to 150 both times.

I have not checked the valve clearance yet, I wanted to check the compression first.

Are these compression values ok? Is #2 a concern? Are the oily plugs a sign of ring problems?

Sorry for all the questions. Oh yes, I am running the original EFI, so there is not really any adjustment, although I could change out my fuel filter and run some seafoam throught it i guess.

Any other thoughts?

thanks much.

Your "Oily Plugs" symptom does not appear to follow the compression results.

The oily plugs can be caused by the intake valve leaking some oil into the fuel intake and coating your plugs.

However, intake valve #2 is probably OK.

Best of success.

Thanks Bill, I guess the next step is to check my valve clearances.

At this point I doubt it's valve clearance. That would affect compression but not oil fouling.

More likely need new seals on the valve stems. If not then new valves. If not then new valve guides. IMHO.

Best of success.

Oh, didn't realize that might be an issue. Looks like I'm taking the head off this year. thanks for the help.

The valve guides could be worn,and the valve stem seals are probably dry and cracked all leaking into the cylinder(s).

What mileage do you have? are you the original owner?

No, I'm the 2nd or 3rd (2nd for sure). Miles: a little over 31k. I've had the bike since 2004 and I bought it with about 27k.

I had planned on doing a clearance check this summer and I already have a valve cover gasket. Looks like I need to take off the head too.

IowaKZ wrote:

No, I'm the 2nd or 3rd (2nd for sure). Miles: a little over 31k. I've had the bike since 2004 and I bought it with about 27k.

Has the head ever been off? If those are the original valve seals, they are probably hosed. They let oil run down the valve and into the cylinder and foul the plugs badly.

I have not had the head off. Can't speak for the PO. I have to assume that the head has never been off.

this should be exciting. I've never taken one of these apart before. Now I have to find the time before it gets too cold out.

Maybe I can spring for a heater for my garage?