CA 77 Only right side running

mattybpt · Post by **mattybpt** » Mon Sep 09, 2013 9:09 pm

I have a 1967 CA 77: Symptoms: firing only on the right side, fouling the right plug (black carbon) within 5 minutes at idle, having difficulty setting idle.
Carb cleaned and jets cleaned twice, original jets, new float, rebuild petcock, new fuel lines, pin set in original position at 2nd slot. Timing and valves set to speck, compression 150 each side, wet compression test had expected increase pressure, good spark on both sides, replaced with used coil on ebay.

brewsky · Post by **brewsky** » Tue Sep 10, 2013 6:12 am

Clipped a little off plug wires?
New spark plug caps?

mattybpt · Post by **mattybpt** » Tue Sep 10, 2013 9:46 am

I did clip a little off the wires and used the original caps.

mattybpt · Post by **mattybpt** » Tue Sep 10, 2013 9:12 pm

Originally when I got it running after sitting for 15 years it was running just on the right cylinder. I replaced the coil and both cylinders began firing, but I was having difficulty setting the carburetor to get a steady idle. Could the replacement coil bad? Should I change the spark plug caps? What in the electrical system cause the coil to go bad? Very Frustrated!!! Almost to the point of taking it to a vintage motorcycle mechanic even though I wanted to fix it myself.

brewsky · Post by **brewsky** » Wed Sep 11, 2013 5:37 am

If you can do everything you said in your first post, then you can figure it out.

If you have good spark both sides, your coil is probably fine.

How did you check the spark? With plugs attached?

To run you need: fuel and air (right mix), compression (above 90 or so), and spark (at the right time).

Re-check your tune up specs, something is off.....float height too hi, float valve stuck open (or in backwards), float hung on gasket, timing or points gap off, idle air circuit in carb plugged.....

Eliminate the possibilities one by one.

mattybpt · Post by **mattybpt** » Wed Sep 11, 2013 9:55 am

Brewsky,

I checked the spark by putting the attached plugs against the engine and had strong spark on both sides. How to you measure spark plug cap resistance with ohm meter? What are the settings? How should the float valve be put in? How do I check the idle air circuit in the carb? I did change the float height a few weeks ago so I will check all the specs again and see what happens. I know something is just off... I will let you know what I find. Thanks.

rrietman · Post by **rrietman** » Wed Sep 11, 2013 10:01 am

M;settle down and start over. the coils rarely go bad. revisit the points/timing first. old coils/wires can sometimes benefit from a slightly larger points gap. set your gap to 16-17, INSTALL NEW PLUGS, get it to fire and run both sides before messing with the carb too much.
Good luck
Randy

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