Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: 0 compression!!!! WTH?

0 compression!!!! WTH? 09 Jul 2020 08:48 #830201

  • krazee1
  • krazee1's Avatar Topic Author
  • Offline
  • Member
  • Member
  • Posts: 100
  • Thank you received: 46
A little embarrassing, but I am willing to share so others may learn from my experience yesterday. Exciting day, first fire-up of the engine that has been disassembled on my workbench for ten years. When I started the project I was going to build a dragbike, so I had a 74 crank indexed/welded, bought some high compression Henry Abe two ring slipper pistons, APE cylinder studs/nuts, a set of APE cams which required modifying the head for lobe clearance, high performance springs and shim under bucket followers. My priorities changed, but I wanted the bike back together so I sold the big cams and installed a set of Webcams with .395 lift. I touched up the valve seats with a Neway cutter, lapped the valves in and did my initial valve clearance adjustment on the bench one cam at a time. I installed the head on the motor to check for piston/valve clearance and did the final valve clearance measurement. When I did the final assembly and checked valve clearance again, I had 0 clearance on the #3 intake, WHAT? Cams back out, shim SOMEHOW had popped out of the recess in the retainer! Cams back in final measurement, everything cool except #3 intake is .18mm which in retrospect probably would have been fine! The next morning I decide to just pop out the intake and reshim #3 to get it in the .10 ti .15 range. I loosened the front cam removed the intake, reshimmed and back together. Yesterday, initial start-up, fires right up on 3 cylinders! #1 exhaust cold, spark, check, fuel, check, compression 0!!!! Remove exhaust, set #1 cylinder at TDC on compression stroke, peek into the exhaust port, and the valve is open. DAMMIT! Remove camshafts, AGAIN! and discover that the shim was popped out of the retainer! Back together, check clearance on ALL cylinders and everything is cool, motor sounds great! I think I was pretty lucky to have a mild cam profile and plenty of piston/valve clearance or it probably would have been a sad day! I can't explain how the hell the shims "popped out" TWICE, but it did happen. I didn't even need to use the shim under bucket with these cams but I had the parts and decided to use them. I should have had all this documented on video like Swest, but the audio would have been X-rated!

Happy now! Mike
Former M.E. at Kawasaki Motors Manufacturing, Lincoln, NE
1966 W1 (the Z1 of 1966-50H.P. and 100mph!)
1974 Z1A (disassembled)
1976 KZ900B LTD (SOLD!) it's in GOOD Hands!
1978 KZ1000 LTD
1976 KZ900B LTD pile O parts!
The following user(s) said Thank You: SWest, Rick H.

Please Log in or Create an account to join the conversation.

0 compression!!!! WTH? 09 Jul 2020 11:15 #830214

  • Rick H.
  • Rick H.'s Avatar
  • Offline
  • Member
  • Member
  • Posts: 579
  • Thank you received: 116
Thanks for the update Krazee! Interesting story to say the least and yes, you really lucked out on this one.

Rick H.
Rick H.

1977 Kawasaki KZ-1000A1

Please Log in or Create an account to join the conversation.

0 compression!!!! WTH? 09 Jul 2020 13:44 #830217

  • Scirocco
  • Scirocco's Avatar
  • Offline
  • Expert Boarder
  • Expert Boarder
  • Never change a running system
  • Posts: 2883
  • Thank you received: 1260
CanĀ“t belive that shims under bucket followers are popped out the shims. On high lift cams shims under buckets are required to prevent shim popped out like on shim over buckets. You must did something wrong during the shim instalation.

Please Log in or Create an account to join the conversation.

0 compression!!!! WTH? 09 Jul 2020 19:47 #830239

  • krazee1
  • krazee1's Avatar Topic Author
  • Offline
  • Member
  • Member
  • Posts: 100
  • Thank you received: 46
Not really much you can do "wrong", with the installation? Shim fits in the recess in top of the valve spring retainer and then you install the bucket. After a day of reflection, I was using copious amounts of cam assembly lube on the lobes. It is possible(maybe?) that the follower stuck to the cam lobe when I loosened the camshaft and slightly pulled it out of the bore, with the shim sticking in the bottom of the follower and then falling off? Like you said, once they are assembled with correct valve clearance there isn't physically room for the shim to come out of the top of the retainer. My lesson learned was that I should have rechecked that ALL cylinders had valve clearance after removing the intake cam and just loosening the exhaust cam. I was just too damn anxious to hear the thing run! Now I'm waiting for a 2" longer rear brake hose(slightly extended swingarm)and bleeding the brakes and it's test ride time!

Mike
Former M.E. at Kawasaki Motors Manufacturing, Lincoln, NE
1966 W1 (the Z1 of 1966-50H.P. and 100mph!)
1974 Z1A (disassembled)
1976 KZ900B LTD (SOLD!) it's in GOOD Hands!
1978 KZ1000 LTD
1976 KZ900B LTD pile O parts!

Please Log in or Create an account to join the conversation.

  • Page:
  • 1
Powered by Kunena Forum