Author Topic: '78 cb550k #4 cylinder intermittent misfire  (Read 839 times)

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Offline tylersilicate

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'78 cb550k #4 cylinder intermittent misfire
« on: September 08, 2011, 09:05:12 AM »
So my #4 cylinder will work fine at idle and then randomly stop firing while I am riding. If I come to a stoplight and let it sit in neutral it will start firing again rinse and repeat. I touch the pipe while I am riding it is ice cold and then while I am idling it is extremely hot just like the others.

What I have done so far:
Checked Spark plug Cap/Wire - Tightened the connection
Replaced the spark plug
Gapped the points
Checked the condensers
Cleaned out the float bowl on the #4 carb.

Anyone got any ideas?

KingCustomCycles.com

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Re: '78 cb550k #4 cylinder intermittent misfire
« Reply #1 on: September 08, 2011, 09:09:43 AM »
Main jet plugged, if you have good balance, manual dexterity, patience, and double jointed fingers, you can pull #4 bowl and remove the jet without pulling the entire rack.

Offline BobbyR

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Re: '78 cb550k #4 cylinder intermittent misfire
« Reply #2 on: September 08, 2011, 09:29:03 AM »
While you are in there adjust your float levels for good measure.
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Offline tylersilicate

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Re: '78 cb550k #4 cylinder intermittent misfire
« Reply #3 on: September 08, 2011, 09:45:18 AM »
I replaced the float needle just last week (the problem existed before then) in hopes of fixing it. So hopefully clearing the main jet will fix it. I plan on doing that tonight.. Assuming I make it home on the bike..

Offline tylersilicate

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Re: '78 cb550k #4 cylinder intermittent misfire
« Reply #4 on: September 08, 2011, 06:06:21 PM »
Cleaned the main jet.. Haven't had a chance to ride it..

Battery keeps dying.. I bought a brand new one a week ago, already dead.

I hooked up a multi meter to and the voltages increase when I rev it.

Is there anything electrical that could be causing my issue?

Offline tylersilicate

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Re: '78 cb550k #4 cylinder intermittent misfire
« Reply #5 on: September 10, 2011, 02:01:38 PM »
Well as posted before I cleaned the main jet and I am still having issues.

Any other ideas?

Offline Danno

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Re: '78 cb550k #4 cylinder intermittent misfire
« Reply #6 on: September 11, 2011, 12:19:54 AM »
bad ground wire form the frame to the battery but will not cause the driveability issues just the charging issues
when you own a motorcycle the wife does not have to find you handy she just has to find you