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Two cylinder determined to be a one cylinder

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ramwing7
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Location: Fayetteville, Arkansas

Two cylinder determined to be a one cylinder

Post by ramwing7 » Sat Feb 25, 2017 6:05 pm

I have a CL77 Scrambler that does not run on the left cylinder.
The timing is spot on
The plug fires strongly when grounded to the head
There's raw gas vapor being blown out the exhaust pipe when it's running on the right cylinder.
I did the spray around the carb insulator to see if there's a vacuum leak; nada

So what's left for me to check?
Gotta be something>

Thanks.

Nick
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Location: Paradise

Post by Nick » Sun Feb 26, 2017 1:45 am

Check valve clearance on that cyl., confirm compression.

Switch plugs between left/right, a weak plug can fire in ambient pressure but fail under compression.

Clear the dead cyl of unburned fuel so that it doesn't immediately foul the clean plug.

Remove air cleaner and ensure that choke is not dropping down/defective, etc., and that slide is moving up/down properly.
If still no joy remove carb and check for water, float level, jet sizes, etc.

Check timing at both sets of points, if using strobe, check on both high-tension leads.

Etc.
Do what you've always done and you'll get what you've always had.

ramwing7
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Joined: Tue Apr 05, 2016 10:44 pm
Location: Fayetteville, Arkansas

One cylinder determined to be 2

Post by ramwing7 » Sun Feb 26, 2017 2:02 pm

I dropped the main needle one notch. It's now in the last notch from the top.
It n0w runs some. It's not hitting every time, but enough to warm up the exhaust.

What's that tell me?

cknight
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Location: Daytona Beach, FL

Post by cknight » Sun Feb 26, 2017 2:25 pm

You might try removing the left carburetor float assembly, and make sure that there's no fuel that has leaked into one of the floats. This would cause it to weigh more, holding the valve open, and flooding that cylinder. Regards, Chase

ramwing7
honda305.com Member
Posts: 41
Joined: Tue Apr 05, 2016 10:44 pm
Location: Fayetteville, Arkansas

Two cylinder determined to be a one cylinder

Post by ramwing7 » Sun Feb 26, 2017 4:04 pm

Thanks, Chase
Did that already. Float and setting appear to be fine.

Next task is to pull main jet and see what size it is and maybe try a smaller one.
Anyone know what the original size was/is?

G3
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Joined: Fri Jun 07, 2013 12:55 am
Location: Sunny Southern California

Jet size

Post by G3 » Sun Feb 26, 2017 11:08 pm

Site Search reveals;
Main 130
Slow 38

Nick
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Joined: Thu Oct 15, 2009 2:03 am
Location: Paradise

Post by Nick » Mon Feb 27, 2017 12:03 am

If the jetting turns out to be okay and the bike's been sitting a long time make sure the mufflers are clear. It's not unheard of for bugs/mice to build nests in mufflers and plug them up. Try running it without mufflers or air cleaners.

Plug caps?
Do what you've always done and you'll get what you've always had.

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