Valve Timing Advice

[Paul Hardy]

HI I have just checked and adjusted my Valve clearances on my 95 TB. I was pretty careful when I took of the cam bearing caps and moved the cams to get at the shims to not loose the timing by zip tying the cam chain to the cam sprockets. and I also put a zip tie around the base of the chain above the crank sprocket however I only did this as a second thought after I removed the cam tension-er.
I also made the basic mistake of not checking the timing marks before I started to pull things apart.

So anyway my problem is after the re shimming etc and putting the cams back in and checking the timing as per the Haynes Manual things are not quite right. mainly if I line up the arrows on the cam sprockets as per the manual The TDC mark on the ignition rotor does not line up with the center of the pick up coil. ( See Photos) SO has the chain slipped a tooth or to on the crank sprocket or is this some sort of timing advance or retarding as part of specific engine tuning. Any help of pointing me in the direction of some would be much apriciated.

 

[shanered6]

Yes I would say you've slipped a tooth or two ! But does it line up on TDC or on the firing stroke BTD ? Just a thought !

 

[Paul Hardy]

Yes I would say you've slipped a tooth or two ! But does it line up on TDC or on the firing stroke BTD ? Just a thought !

HI shanered6

Yes I have been looking at this a bit more and I think your right about slipping a tooth. Ignoring the manual and thinking trough the process I think I have got it sorted. When I set number 1 at TDC with both valves fully closed and the cam lobes horizontally opposed and setting crank timing mark to the correct position I was out a couple of teeth. Now when I turn the motor through the firing cycle every thing lines up IE. number two TDC both valves fully shut the timing wheel lines up with the number two TDC mark and number three etc. . What I think through me out was the timing arrows on the cam sprockets are opposite to the Hayes manual they point out rather than in. My only explanation for this is that someone has reassembled the wrong sprocket on the wrong cams at some stage maybe ?

 

[shanered6]

Sounds like your sorted !
Your probably right about the cam sprockets as they fit both ways for some reason ? On most bikes the holes are off set so they can't be swapped, well good luck getting back to get her and fired up .

 

[Paul Hardy]

Just a follow up. The bike starts and runs, so not quite sure why the cam sprockets would have got swapped around, I am sure you could remove the cams without removing the sprockets, Maybe some one has fitted new cams or something, could have even been done at the factory maybe.