Newbie ring job attempt -*updated!*

Well here's my story, I hope you guys might have some advice for me...

I just got a 1999 KZ1000 police with 20,000 miles on it. They guy I got it from rode it about once a week last year, then parked it for the winter. He then went and tried to turn it over and it wouldn't. He had someone check it out and it turned out to be bad compression which improved with the oil down the sparkplug hole test, so I knew the rings were bad. I pulled it all apart and everything looked ok, not too much fouling on the pistons and head, no scratches or anything in the cylinders. I don't have very good tools and when I would drop the pistons in from the bottom of the cylinder and measure around the skirt with a feeler gauge (like in the clymer manual)they came in spec (one was barely though). I threw new rings on and bolted it all back together (after swearing for 3 hours trying to find were the cam chain tensioner pivot had gone -- making sure that it was not in the case by pulling the oil pan and looking all over creation -- I guess it was not there to begin with?? so I had to cut down some 8mm stock and fab one up) Also I did not have a hone, so it was not rehoned...

Well still have bad compression, in fact worse than before 1 and 4 show about 30 and 2 and 3 don't even show. Again compression improved to over 120 by putting some oil down the holes.

As money is a big issue.... would re-honeing fix anything or is this something that I would have to re-bore and buy over sized pistons? If I do have to get new pistons, is there anywhere I can get them cheaper than $400?? (ouch!)

Also something that was a bit worry-some, while I was rebolting the thing together two bolts on the exhaust camshaft cap (the upper left on #1 and upper right on #2) would tighten down with my torque wrench then suddenly spin free-er -- not like the bolt broke, there was still some tension on it holding it down... I left them cause they were holding things down and I didn't want to make things worse -- I just wanted to get it back together. Did I bust the threads or something, how hard is it to re-tap the aluminum cylinger? Remember I have basic hand tools -- I would have to go buy a tap, but saving money is key....


Does anyone have some words of advice? Thanks!!

Post edited by: Beepy, at: 2007/05/12 23:55

Will it start? Will it run? If yes, how long have you run it? Rings take time to seat.
My local engine guru was telling me that with new rings the latest theory is no honing if you haven't rebored, so my advice is, if it startes and if it runs, put some miles on it, and not necessarily easy miles, either.
About the cap bolts, :ohmy:
I haven't had experience with that, so let somebody else chime in.

Will it start? Will it run?

... nope not enough compression to get it to start (and when I did the last oil test compression I tried it in all cylinders to get it to start, but by that time the battery was dead ... so I need to charge it)

These things are pretty intricate. Maybe not as refined as a turbine engine, but still. . .

A 20k motor with no compression, and stripped cam saddle hold-down bolts.

The cam saddle holes can be repaired with a heli-coil. You will have to plan on about $25.00 for the kit and the drill bit. You will get enough inserts to repair up to ten holes I think. Sometimes more. What did you torque them to? There is a couple of ways to do the cam reinstallations, some of them wrong.

Low compression on all four cylinders indicates that maybe something is off besides new rings. Maybe valve timing. Or something worse.

Hones are cheap. Usually less than 40$. A machine shop might have honed your cylinders as a courtesy. At this point, I don't know if honing will help or hurt. For all I know, maybe your rings are installed incorrectly.

Did you really think you could rebuild a four cylinder engine for less than 60.00?

Maybe you can take the cylinder and the head to the machine shop and they will take care of issues for less than what you want to spend at this point.

I don't think you need pistons.

But since the job was not done right, it is going to have to be done over.

Did you replace the head gasket, or reuse it?

Beepy wrote:

... 1999 KZ1000 police with 20,000 miles on it...parked it for the winter...tried to turn it over and it wouldn't...bad compression which improved with the oil down the sparkplug hole test...all apart and everything looked ok, not too much fouling on the pistons and head, no scratches or anything in the cylinders...measure around the skirt...in spec...new rings...not rehoned...still have bad compression, in fact worse than before 1 and 4 show about 30 and 2 and 3 don't even show. Again compression improved to over 120 by putting some oil down the holes...would re-honeing fix anything or is this something that I would have to re-bore and buy over sized pistons? If I do have to get new pistons, is there anywhere I can get them cheaper than $400?? (ouch!)...two bolts on the exhaust camshaft cap...would tighten down with my torque wrench then suddenly spin free-er -- not like the bolt broke, there was still some tension on it holding it down....Did I bust the threads or something, how hard is it to re-tap the aluminum cylinder?....

Should not need new pistons after only 20,000 miles. Were end gaps on new rings staggered when reassembled? Would check valve clearances anyhow. Was all compression testing done with throttle held wide open, all plugs removed, while spinning over with electric starter?

Believe some threads are stripped inside the aluminum head where the steel cam cap bolts screw into. Might do a search for "cam cap bolts" in the search box above for some good articles about repairs with heli-coil and how to re-install cam caps with less chance of stripping.

Post edited by: Patton, at: 2007/05/10 14:28

Beepy wrote:

... not enough compression to get it to start (and when I did the last oil test compression I tried it in all cylinders to get it to start, but by that time the battery was dead ... so I need to charge it)

All that oil added into the combustion chambers probably prevented any ignition of incoming fuel mixture. Believe any motor would be difficult to crank under those conditions. Suggest removing excess oil residue from combustion chambers, and not put anymore oil in them, even for testing.

I used all new gaskets and rings. I was careful to stagger the rings like the clymer manual said. I also couldn't get the valve springs compressed (the two auto compressors I had wouldn't work), but the valves held solvent without leaking and they did look in good shape. I was going to go back and do all the valve clearances when I got it running and broke in....

I did think of getting a cylinder hone, but did not trust myself to keep it from getting out of round with and electric drill!

Beepy wrote:

... going to go back and do all the valve clearances when I got it running and broke in....

Would check valve clearances before installing valve cover and especially before attempting to crank up the engine.

Hate to tell you this but I would bet that when the previous owner parked it for the winter he did not winterize it. When the bike sat the rings got stuck in their grooves. Then when you try to start it, low or no compression. I have had this happen to me many times when I bought someone elses bike. I poured Marvel Mystery oil down the cylinder, let it sit for a few days and the compression comes back.
Your current problem is most likely something was assembled incorrectly. I would recheck your work. You can re-use the gaskets if the engine had not been started so it shouldn't cost anything to re-check the work. Good luck.
The cam cap bolts are stripped and need to be repaired.

If you aren't showing any compression at all on 2 cylinders it seems that the valve timing is off. Recheck that before doing anything else,,, hopefully you haven't bent the valves.

where are you and the bike?

Hmmmm... the stuck rings are possible, I will talk with the guy today. I am planning on tearing it apart this weekend to re-check everything, this is my first motorcycle build -- though I have done some chevy 350's before. I am pretty sure the valve timing is right though, I followed the clymer manual to the letter (ie the 44th pin facing the in mark, both cams at thier indexes while #4 is TDC) I will check that this weekend too.

I am in Spokane WA.... Thanks for the help so far!