Checking the valve timing on a 400.

[McCabe-Thiele (Ted)]

Not sure if it's genuine shoots of recovery or that we opened a bottle of red this evening but I was driven into the garage for just 15 minutes this evening.
With spark plugs all out with some soft bungs wrapped in cloth over the plug holes checked the valve timing (again) as directed by Bryan.

Started with number 1 cylinder at Tdc mark - gently rocked the T bar a few  degrees either side of T - no movement in the Inlet or Exhuast valve rockers. CHECK

Rotated the engine a full 360 deg turn so mark on Tdc again (exhuast stroke) -gently rocked the T bar either side - both Inlet & Exhuast valves moved immediately  up & down at the same time  either side. CHECK

Looks as though I had just forgotten how I did it all those months ago so all anxious over nothing. On re- reading my CB400 & CB550 Haynes Manual I do recall it flitted between the two models but the photo markings in the book clearly show the T mark.................................relief.

Anxiously awaiting affirmation from Bryan ...........

[Bryanj]

Sounds good to me and the valves cant be hitting as it turns over easily!

[McCabe-Thiele (Ted)]

Sounds good to me and the valves cant be hitting as it turns over easily!

Thanks for your guidance Bryanj. Cheers Ted

[McCabe-Thiele (Ted)]

Yesterday I spent some time reading my Project Board Rebuild  Blog from the start there was a photograph I had taken from when I fitted the timing chain - including the timing mark at 1/4 TDC all that angst for nothing! lol

P19 there was this  photo here so I did fit it at TDC mark - I took a photo but did not type text in my documented log.


TDC crank marks by Macabe Thiele, on Flickr

[McCabe-Thiele (Ted)]

Not sure if it's genuine shoots of recovery or that we opened a bottle of red this evening but I was driven into the garage for just 15 minutes this evening.
With spark plugs all out with some soft bungs wrapped in cloth over the plug holes checked the valve timing (again) as directed by Bryan.

Started with number 1 cylinder at Tdc mark - gently rocked the T bar a few  degrees either side of T - no movement in the Inlet or Exhuast valve rockers. CHECK

Rotated the engine a full 360 deg turn so mark on Tdc again (exhuast stroke) -gently rocked the T bar either side - both Inlet & Exhuast valves moved immediately  up & down at the same time  either side. CHECK

Looks as though I had just forgotten how I did it all those months ago so all anxious over nothing. On re- reading my CB400 & CB550 Haynes Manual I do recall it flitted between the two models but the photo markings in the book clearly show the T mark.

[scifi]

Most four strokes have a position where at TDC the valves are 'Rocking'.   So if you get your multi cylindered engine to TDC, one set of valves will be rocking.
For real accuracy, you could measure the piston movement with a Dial Test Indicator ( DTI.)

There may be some very rare exceptions to this rule, where there is some designed asymmetry of the camshafts.