I just got a 1965 CA77 a few weeks ago and seem to be having carb problems. I keep fowling plugs due to a rich mix (black dry plugs). I took off the original air cleaner because it was well, old and no good to see if that might help....nope.
I noticed when I got the bike that the air screw was turned all the way in. I turned it out 1.5 turns and played with the idle screw tell it sounded good. I drove it about 8 miles and it ran great yet wanted to die at idle after a while. The next day it wouldn't start. Pulled the plugs and found them fowled. I cleaned them and it ran fine but the fowled again.
There is gas coming out of the over-flow on the bottom of the carb. Not a lot but enough to drip down the case and onto the ground to make a half-dollar size puddle.
I am running NGK D8HA plugs. Should I try D6HA plugs? What is the gap for the plugs?
What are stock jets for the carb? I am at sea level but the bike came from Seattle (which I think is also sea level).
I have ordered a new set of points and a new condenser and am looking for a new coil.
Any suggestions on a new coil?
And any suggestions on what I should try next?
carb Problems CA77Sounds like you need to get intimate with the carb.
Remove it and clean all the passages and blow out with compressed air. Remove the jets and make sure all the holes are open. 120 main and 35 slow jets are stock. Make sure the float valve is not sticking, and the tip is not deformed. Make sure there are no pinholes in the float. Set the float level to 26.5mm from the gasket surface of the carb body when the float tang just touches (but not depresses) the valve tit. Set the air screw (closest to engine) to 1 1/2 turns out. Set the idle speed screw till it just contacts the slide. Make sure the mounting flange is not warped and don't overtighten the nuts when re assembling. (around 4 ft-lbs is plenty) This should get you in the ball park. 66 dream, 78 cb750k, 02fz1, 09 wing
I did EVERYTHING you suggested with no luck. I bought a new set of Keyster stock jets but did not swap out the needle as I was told that the Keyster needle will only add to my problems.
The only thing I am having probs with is setting the float. I can't seem to get it right. One setting poors gas out the overflow and the next time I try it isnt getting enough fuel. If I can get the float setting right and it still is too rich, should I move onto the needle setting? Right now it is smack dab in the middle setting. If it is too rich I assume I need to bring the clip down a notch, is this right? And if I move it all the way down and am still running too rich, Do I need to get a smaller (33) or a larger (37) size air jet? (I am assuming that the sizes go by 2's like the main jet does). I also have a new set of points, coil and condenser that I will be putting on as soon as I can figure out the carb problem.
I think my prob is that too much gas is getting past the valve-set and into the bowl even when the float is all the way in it's highest position gas still flows in. Is there suppose to be a paper gasket between the carb and the valve-set? Mine has a very thin metal washer. Is this right?
If the float is all the way up in the highest position, should there be NO gas getting into the bowl? L: yes a metal washer on the needle valve seat is correct. setting the float level shouldn't be that tough. with the keyster needle valve installed and the level set, everything will work. unless your float has a leak, which sounds likely. put it in a bowl of solvent for 30 minutes, see if it floats or sinks. you must get this right before going any further. as far as setting the jet needle, consider it this way, lowering the needle into the jet (raising the clip) leans it. raising the needle out of the jet(lowering the clip)richens it. also you MUST competely clean the carb/passages/jets with carb cleaner/compressed air. paying particular attention to the idle jet and passages.
good luck Randy
I did clean it out with compressed air and put in the new jets (all stock sizes). The only think I didnt replace was the needle as I have heard that Keystear needles are horrible, so I kept the original one in.
When I shake the floats I hear no gas inside but, I will order a new one just in-case. That way I can eliminate that as the problem. Should gas get past the valve-set when the bowl is all the way up?
uh-uhdon't think so.. no expert here, but this seems easy so I'll take a stab at it....I'd check the valve stem and seat. might be less messy to hook a clean hose to banjo and blow gently (by mouth) to check it. '62 CB77. "It's a rider."
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