Motorcycle Repair: cb77 jetting, air leaks, core wires

Question
Hi,  I have a 1964 cb77 that has a hesitation right off idle that wont go away.  I have tried every needle position posible and the best position is at the very bottom (richest position).  It runs the best at the bottom, but it still hesitates. It seems to me that it needs more fuel and I was wondering if you thought a larger main jet would affect the mid throttle.  I have a 135 main and 42 piolot.  My altitude is about 1600 feet.  I have also set the timming to exactly what my manual says and I have new points, condensor and plugs.  The wires and coils are original and that brings up another question.  The original wires are solid core.  Have you used supresion core wires with any luck?  My bike doesnt seem to run well with these and I am having a hard time finding solid core wires.  Do you know where I can get some new wires?  Any help would be greatly appreciated.

Thank you
Eric  

Answer
Eric, 1600 ft can be a threshold for actually leaning the motor out a bit, at least on the main jet. First, you do have to review all of the other factors...
Compression... same on both sides?
Intake air leaks... O-rings at spacer and carb body and possibility of warped carb body flange causing air leaks.
Ignition timing... I don't know which book you are reading for tuneup, unless it is mine, which says CHECK the timing with an automotive timing light, engine running. Be sure that neither side is over-advancing beyond the II marks on the flywheel/rotor. Once you have determined that both sides are maxing out at 45 degrees above 3300 rpm, then look at the initial idle timing. It will probably be F mark on one side and T mark at the other side. This is due to slop in the point camshaft, running inside the right side camshaft. You can't compensate for this with worn parts. What happens is that one side is starting from TDC and the other side timing is 5 degrees BTDC, so they are never a match until the spark timing hits 3300 rpm. All this is dependent on the wear in the advancer sprocket parts (springs and rivets). If the springs are stretched or broken, the timing comes out too soon, plus it is uneven on both sides during acceleration! The only real cure for the timing issues, besides replacing the sprocket, springs and point cam is to install the electronic ignition system, that I helped develop.

As far as plug wires, check with speed shops, tractor supply shops and perhaps Brit bike shops for solid core wires! Also, the spark plug caps are non-resistor, too! Putting resistor wires/caps on these bikes will hamper spark output, usually, as you have found out.

http://www.racingjunk.com/post/605280/MOROSO-SOLID-CORE-IGNITION-WIRE.html

Maybe check with vintage VW repair shops for wires like that, too.

Keep reading your spark plugs (D8HA NGKs), looking for signs of over-richness, lean-ness or detonation. Use high test gas, but no octane boosters or lead additives are necessary.

Bill Silver
www.vintagehonda.com