Author Topic: 1978 cb750  (Read 1039 times)

0 Members and 1 Guest are viewing this topic.

sheldonth

  • Guest
1978 cb750
« on: August 06, 2008, 09:22:34 PM »
Could anybody tell me , (once and for all), what the firing order is on my 750k? I need
the piston numbering from left to right as your sitting on the bike, and the order of
the coil, (which nub to which cylinder). The mechanics tell me one thing, the book another,
and my stomach, yet another. This bike started as a rat bike, but when I got done, it
had turned out too nice to call a rat bike, and it was running enough for me to cruise around town for an hour.
   I then decided to clean the carbs, and when I started her back up to check her out,
I think I lost my coil. I do not understand the book, as it says to test between yellow
and blue leads for around five ohms. There is only one blue lead, and one yellow,
so do I touch the other end of my testor to ground?
   Last night I tried yet again to get spark, I got intermittant spark, but nothing
steady.  Any advise would be greatly appreciated.

p.s. I think I posted this to welcome area by mistake, (I'm new), I apologize
if this is the case.

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,802
Re: 1978 cb750
« Reply #1 on: August 06, 2008, 11:12:43 PM »
As you sit on the bike #1 is on the left, then 2, 3, 4.

The coil with the blue wire fires 1 and 4.

The coil with the yellow wire fires 2 and 3.

If you want to test coils, the FAQ has some info already typed up. But, you measure primary resistance between the blue (or Yellow) and a Black/White leads of each coil. (About 5 ohms.)

Make sure your point contacts are clean.

Cheers,

Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.