Topic: wrong camshaft ?

[Lozscott]

Hi all , really hoping someone out there can help . I was posting last week ( 'gutless engine' ) about my 400 that wont rev and lacks power , it was suggested i had got cam timing wrong .I was very disappointed to find the cam timing was fine , sprocket lines level at TDC ( would have been a quick easy fix ) . After a bit of head scratching i decided to check valves to the angles in my haynes manual , can anyone verify that they are correct ? 
    ( There was supposed to be a pic here but cant get that to work either ! )
The 5 degrees BTDC for inlet opening was an easy check , should be close to static timing mark , mine was well before the advance marks , about 35 degrees ish BTDC . Exhaust closing was well off too by about same amount .
  Right ...this is a bit odd ! , so off with rocker cover again , moved chain one tooth ( lines definitely not level now ) , cover back on , re checked and IO and EC now look correct ( as best as i can guess ) Went out for a spin , engine now revs a lot better , still down on power and wont tick over any more
    I re checked compression , it wasn't great at around 120/125 psi last check , now its around 100 psi
  So please has anyone got ideas Are there any other cams that could have been fitted at some point . My cam sprocket is a solid one , are there 2 types as most pics show one with holes in , but it is same no of teeth and bolt holes at 90 degrees to lines
    I have a timing disc in the post so will check valves more accurately next week , Loz

[American Locomotive]

I'm not too familiar with the construction of the camshafts on these bikes, but is it possible the cam-gear hub could have rotated on the camshaft? I've seen it happen on Honda's offroad bikes before.

[Bodi]

Checking valve timing depends on what the "rules" are, and the Honda book doesn't specify them: commonly you set zero lash in the tappets and the spec open/close angles are at .050 valve lift. This info may be in the common service manual but I don't know what Honda specs but measuring at 0.050 doesn't match the angle specs. Better to measure the open and close angles at some arbitrary lift, calculate the lobe centre from them, and compare to the calculated centres in the specs. That's what I've done with cam timing, anyway. It eliminates needing the lift spec where the open/close angles should be measured. It doesn't let you measure the duration to see if it matches the spec, but wtf... not something you can change anyway.

[dave500]

the cam sprocket is solid they cant slip,your marks are correct you've checked,if its had a hotter cam fitted that you don't know about that will lower the dynamic compression,thats often why static compression is raised when a hotter cam is fitted,im using the hot cam term here loosely,youve been right over your ignition?

[Lozscott]

Hi all , the problem continues !! I fitted a timing disc and re-set cam back to marks , verified that valves opening early and closing late . I then used angles in the haynes specs to set valves with zero clearance at opening points , they also close at correct angle now . Compression now increased to a healthy 140/150 psi . Unfortunately i had to back adjusters off by 2 full turns to achieve this ( about 1mm ) so tappets are like nodding donkeys at adjusting position . bike runs a lot better if a bit noisy !
  Thinking i might have a rogue cam i have bought another one ( yet to arrive ) but i cant see it really . Got cam out again and it looks fine , Does anyone know if cam followers wear flat , it may have spent many years with crap oil and bad adjustment ?
   Any ideas greatly appreciated , Loz