69 tr6r
When the engine is under load like going up a hill and accelerating the engine will knock but sounds more like a rattle. The throttle is usually between 1/4 and half throttle when this happens. If I down shift or roll slightly off the throttle it quiets down.
I cannot tell what rpm
I get the knock.
"up hill", "accelerating", small throttle opening, that it goes away if you "down shift or roll slightly off the throttle" suggests detonation or pre-ignition. Both are very bad for any engine.
Take a look at the piston tops. If patches of piston are visible, instead of a uniform covering of soot, those patches were cause by detonation blowing off the soot in those areas. That is very bad. If you do not fix the causes, the engine will hole one or both pistons.
the bike did run ok the last time it was on the road in 1996
That was 25 years ago.
messed up the ignition advance unit. So I installed a pazon electronic ignition
the bike runs good but still knocks when hot and under load. I set the timing as best I could
my tachometer is frozen and broke the cable
I cannot tell what rpm it is timed at or what rpm I get the knock.
So your problem might be nothing more than you have not set the timing accurately, possibly too far advanced?
Set the timing accurately. If you cannot fix the bike's tachometer, a near match Emgo pattern one for sixty bucks is much cheaper than an engine rebuild.
Or buy a cheap one that works attached to an HT lead. Or use a strobe with a rpm indicator. These might require some calculation because they are usually set for a four cylinder engine and distributor, where each spark plug fires only every other crankshaft revolution; otoh, your bike is effectively a single cylinder firing every crankshaft revolution.
Once you know the timing is set correctly, one possibility to alleviate the symptoms the bike is experiencing is retarding the full-advance setting by one or two degrees.
engine is under load like going up a hill and accelerating
throttle is usually between 1/4 and half
Mark the throttle housing beside the handgrip where you can see the mark when seated on the bike.
Mark the handgrip beside the throttle housing with four marks corresponding to 1/4, 1/2, 3/4 and wot.
When you are riding and experience an unusual condition look at the handgrip marks, you do not have to guess the throttle position.
engine is under load like going up a hill and accelerating
throttle is usually between 1/4 and half
Try using a lower gear and more engine rpm. A '69 TR6R is not a Hardly Dangerous, you cannot ride it like one.
