Originally Posted by Egrafx
1968 TR6R with points ignition.
Basically, I would like to adjust timing as a first step to try to eliminate pinging/pinking. Bike is rebulit and runs and idles excellently, just pings likes crazy when warmed up and under load.
'68 can be "FUN" ,but still easier than earlier models.
You have an inspection plate oth the primary case,over the rotor.The rotor has a timing mark stamped on it,but there is no pointer on the primary case to line up with it.
The pointer was a separate tool D2014,only used during service.You could file a notch in the hole to line up with the rotor at 38 degrees BTDC,and you wouldn't need that tool.
You need to accurately find 38 degrees BTDC.If you have a timing plug hole at the lower front of the lower front of the crankcase,that will be the 38 degree hole.If you only have a timing plug hole behind the cylinder barrel,you can locate BOTH 38 BTDC and TDC from that hole with the timing plug tool.
You can use a small socket with a Phillips screwdriver in it,instead of the timing plug tool,to locate the 38 degrees BTDC notch in the flywheel.Start with the pistons at TDC,then rotate the engine backward until the pistons have dropped 0.415".The timing plug tool should find the flywheel notch for 38 BTDC.
Provided the rotor is not loose on its centre,you can now make a reliable timing mark to line up with the rotor mark.Your mark will be approx 38 degrees forward from the rear bolt hole for the inspection cover.
THAT WASN'T HARD.NOW YOU HAVE A TIMING MARK for 38 BTDC.
You will need a timing mark,and you need to know the degrees BTDC when it lines up exactly with the rotor mark.
Standard ignition timing for your engine was 38 degrees BTDC,when it was new and good fuel grew on trees.35 degrees would be a safer bet these days,if you want to avoid detonation and holes in pistons.That puts the rotor about 0.075" anti-clockwise from the timing pointer.
You could just connect a timing light to each plug lead,and check the timing of each cylinder at full advance.You need to rev the engine until it stops advancing (reaches full advance),which will happen above 2000 rpm and possibly even 3000 rpm.
If the timing is too advanced on both cylinders,undo the 2 pillar bolts at the points plate and rotate the points plate clockwise about 1/2 as much as the timing error you saw at the rotor.Check the timing again.
If you check the timing statically,as described in the manual,you don't actually need to lock the AAU at full advance.You can just twist it clockwise to the fully advanced position,and see if the points open.You need to have the engine at 38 degrees (or 35) BTDC when you do this.Set the engine position so the rotor mark lines up,or lines up where you want full advance.
For more information,do a search on this site: "secondary plate" or "2ndary plate".