Author Topic: 3 and 4 warm at first until...  (Read 600 times)

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Offline evinrude7

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3 and 4 warm at first until...
« on: April 17, 2017, 03:00:22 PM »
came home today and tried to get a quick ride in before the rain.  3 and 4 weren't firing.  took it a few blocks and it was definitely running on only the left side.  i figured it would get warm and then 3 and 4 would start to fire.  they eventually did on my limp back to the house so i turned around and took it through the neighborhood without much incident.  a little boggy on more throttle but eventually that evened out. 

rewind a couple days: on saturday i did valve tappet adjustments and filed/adjusted points but i rode it after that without any issues.  in fact it ran great.  after the ride i took the plugs out and checked gap on all of them and checked resistance on all my plug caps as i never had and was curious about that part of the puzzle.  i found a vacuum leak in my airbox boots and think i corrected that to an extent.  put everything back the same way.  nothing different.  didn't ride it easter sunday as i was hung over as fuk.  however saturday night i ran it in the carport a little.  started one kick.  sounded great. 

i have noticed my battery at rest is around 11.5 v.  i haven't sorted the charging issue yet.  i noticed 14.5 v at 3,000 rpm the other day.

just wondering if anyone else can tell what, out of this description would cause this weirdness.  i haven't had a cold cylinder(s) in a while.  especially since i sorted my float height issues weeks ago. 
cb750 k6 - ugly

Offline 700504

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Re: 3 and 4 warm at first until...
« Reply #1 on: April 17, 2017, 03:43:55 PM »
Check for fuel in all four carbs, you may have fuel delivery issues.
1978 cb750k
1977 cb750f2
1974 cb750k
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1981 cb650 (rip)
1969 ct90

Offline evinrude7

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Re: 3 and 4 warm at first until...
« Reply #2 on: April 17, 2017, 03:55:23 PM »
i think you nailed it 700504.  i recall, after jacking around with my airbox boots that the fuel line from where it T's off was a bit squished.  i'll have to fix that.  thanks man. 
cb750 k6 - ugly