Engine Rotation Locking

  • Buffalo515
  • Buffalo515's Avatar Topic Author
  • Offline
  • User
  • User
    Registered
  • Posts: 66
  • Thanks: 15

Engine Rotation Locking

Today 13:22
#925529
Been rebuilding this 1985 zx550A. The entire engine has been taken apart and put back together. When i try to rotate the engine with the cams in it stops at 2 places. Heres some troubleshooting ive done so far.

-No bent valves. I pulled the head after this condition to make sure again after this. 
-Timed the cams according to service manual and louds graphics. 
-engine rotates freely with cams removed so i think bottom end is fine
-Checked valve clearances for each valve. All meet the minimum clearance so its not a lack of clearance. 
-Ive removed the tensioner and still experience this condition while rotating with hand pressure keep the chain on the sprockets. 
-Everything is oiled with a light coat of oil and the caps are torqued to spec in order of service manual
-It stops at the same two spots every time. (Intake 1 and Exhaust 2 depressed / Intake 3 and Exhaust 1 depressed). 

Ive included pictures of my cam timing and of the positions of everything in these two spots. Let me know what you think im kindve lost. 
Travis
Maryland
1981 GPZ 550 -gone
1984 GPZ 550
1985 GPZ 550

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

  • StreetfighterKz
  • StreetfighterKz's Avatar
  • Offline
  • User
  • User
    Registered
  • Posts: 1633
  • Thanks: 227

Re: Engine Rotation Locking

Today 14:15
#925530
You show multiple “timing mark” pics as far as I can tell.  The cam lobes for #1 are typically facing directly toward each other when 1&4 are at TDC. It’s really hard to tell from your pics is that’s the case.

Later, Doug
1978 z1000 Streetfighter
1976 z900 ‘Stripfighter
1978 z1000 w/RC Turbo
1979 z650 Resto-Mod
1983 Gpz750 Resto-Mod
2018 Z900RS

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

  • StreetfighterKz
  • StreetfighterKz's Avatar
  • Offline
  • User
  • User
    Registered
  • Posts: 1633
  • Thanks: 227

Re: Engine Rotation Locking

Today 14:22
#925531
The lobes on #1 can also face away, as that would be the compression stroke as the exhaust lobe would be close to opening the valve.

Later, Doug
1978 z1000 Streetfighter
1976 z900 ‘Stripfighter
1978 z1000 w/RC Turbo
1979 z650 Resto-Mod
1983 Gpz750 Resto-Mod
2018 Z900RS

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

  • Wookie58
  • Wookie58's Avatar
  • Away
  • Moderator
  • Moderator
    Registered
  • Posts: 6532
  • Thanks: 4123

Re: Engine Rotation Locking

Today 15:25 - Today 15:34
#925532
As well as the timing marks have you confirmed correct pin count between the sprockets ?
you say it locks in two places, have you forced it past the first one to find there is a second?
rotating the motor while trying to tension the chain with your hand is a recipe for disaster. Reset the marks with the tensioner removed and the correct pin count, refit the cam cover, reset the tensioner then try to rotate the motor 
Last edit: Today 15:34 by Wookie58.

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

Moderators: Street Fighter LTD
Powered by Kunena Forum