This bike is still not running right. I've changed the plug, coil/ht lead, and cdi unit and carburettor. I don't think there's anything else so maybe the valve timing is out? I'm putting a blog on this as these later 12v machines just don't seem to be covered in "Haynes".
The Generator/starter cover doesn't need to come off, remove the two plugs. You can rotate the motor through the side cover and check for marks through the top.
The top plug has an indicator groove.
Rotate the motor (spark plug out) until the "T" mark lines up with the groove
The camsprocket cover is a mystery as unlike earlier models it has no obvious bolts securing it.
In fact it's held on by a long bolt centre of the finned cover on the opposite side.
Loosen this bolt and the camsprocket cover pulls off (care with the gasket if reusing)
This shows I have the motor at tdc on exhaust not compression, the O mark is opposite the indicator not next to it!
Rotate the motor to the next "T" mark and the "O" aligns perfectly. Sadly this means valve timing isn't my problem!
Should add that I once had a moped where the camshaft had been changed and the markings were no longer a useful guide. In that case I had to check valve timing manually. Ive now acquired a used motor. I checked both for the position at which each of the valves open. Both behaved similarly so I think the motor must be right.
