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Discussion Starter #1
Hi All,

I have a barn find 1973 CB350 that I finished up last year with help from a local motorcycle mechanic.

With the exception of a Motogadget M Unit, associated wiring harness, & Shockwave electronic ignition, the bike is stock. Stock carbs, airboxes, etc.

A few weeks ago the bike started stalling at idle and I finally figured out that the right side carburetor wasn't working. Cool exhaust, moving the throttle on just that side...nothing.

That also explained the performance issues since I effectively had a heavy 175 instead of a 350 :)

The carbs were rebuilt and all new internals were installed. All of the jetting is stock.

  • I get spark when I test the spark plug.
  • I pulled the carburetor, disassembled and cleaned everything, then reassembled.
  • The right side exhaust is blowing cold air so I know I have circulation.
  • The plug gets wet with fuel on that side.
So I apparently have air, spark, and fuel.

Any thoughts?

Thanks in advance,

Jerry



311909
 

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Put a fresh spark plug in that cylinder, just because that plug fires outside the cylinder doesn't mean it will fire under pressure in the cylinder.
 

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Discussion Starter #3
Put a fresh spark plug in that cylinder, just because that plug fires outside the cylinder doesn't mean it will fire under pressure in the cylinder.
Hi Mike, sorry I should have mentioned...I did that already.

GHEN (Jerry)
 

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Did you put a timing light on the plug wire to verify it's actually firing the plug while the engine is running?
 

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Ah the good ole reliable Shockwave electronic ignition :)
Check to see if the pickup sensors have loosened as this is a very common problem with this EI.
Have a read




Do you still have the points? If so put them back and see if the bike runs on both cylinders.
 

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Discussion Starter #7
Ah the good ole reliable Shockwave electronic ignition :)
Check to see if the pickup sensors have loosened as this is a very common problem with this EI.
I checked my shockwave connectors and they are all tight. Everything looks good there...thanks for the lead though.

Do you still have the points? If so put them back and see if the bike runs on both cylinders.
I'll have to check my box o'parts I got from the builder and see.

GHEN
 

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If you really want to know if you are getting spark on that right cylinder or it's a carb issue do this.

Spray some starting fluid into the right side air box and try to start it. If it catches or sputters and seems like it's trying to start then likely you have a fuel delivery issue at which point I would advise taking that carb off and going through and cleaning it again.

If the starting fluid does nothing then you are not getting any spark at all on that cylinder.

Check your conversation.
 
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