Motorcycle Repair: Honda GL1000, valve stem seals, ballast resistor

Question
Hello Bill,

I have a '75 GL1000 that have have been putting back together for the last 9 months.  Its a long story that I won't bore you with but I bought it as a rolling frame with 4 big boxes of parts.  My problem is that I have it running but not well.  It uses way too much gas and has a back firing problem.  The timing is set per specs and it has new points and plugs.  I have replaced the wiring harness and the wires from the points to the condenser is new also.  (so is the condenser)  Any ideas where I can start trouble shooting?  Thank you in advance for your help.

Mel from NC.


Answer
Mel, Wings aren't my speciality, however there are a few suggestions I could throw out there for you...

Sounds like you tackled a big project.... do you know why it was in boxes, in the first place?

Did you check the mechanical spark advancer for proper function? If the timing is good at idle and at 3500 rpm, then it should be fine, but they do get sticky and seize up. If you only statically timed it, the advancer may be causing some issues. You have to use a little special sight glass to screw into the timing hole to check the timing with the motor running, as I recall.

Going back to the basics.... check the compression to be sure that all 4 cyls are close to specs. If one side is lower than the other bank, you may have the cam timing off a tooth. Hopefully, pistons/rings and valve stem seals are all in good condition.

If you are satisfied with the spark timing, check the spark plug cap resistors and plug wire connections. Resistors should be around 5k ohms and again all 4 should read out close to each other. If all of this seems okay, have the coils tested for output. There is also a ballast resistor in the circuits that could affect spark output.
Leave the point cover off and watch the points for excessive arcing. If one side is arcing a lot then the condenser lead is loose or the condenser is defective.

The central air chamber unit has fuel passages running through it and is sealed with a large gasket around the edges. If that fails, you can get fuel leaks inside and the fuel gets drawn into the intake system unmetered. Intake manifolds have to have good O-rings sealing to the heads and of course the carb sets all have to be clean and adjusted to specs.

Check with http://www.classicwingclub.org/homepage.htm
for more possibilites...

Bill Silver www.vintagehonda.com