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Discussion Starter · #1 ·
Hey all. Not sure if this is something that belongs in electrical, or engine since both are in play here.

My CB350 K4 is only running on the left cylinder. Right fails to fire and has not fired since i rebuilt the bike.

So far I've looked at:

Spark: i do have spark on the right. Did the thing where you see if it sparks outside case when kicked. I do get a spark. And I've checked the gap. The pug comes out clean, just soaked in gas. Both coils are new from common motor.

Timing: Have set timing based on the Common Motor video. I am running a Shockwave system. Which makes reading through old threads a little bit harder.

Compression: Solid compression. First thing i checked when buying the motor. Have also set the valves and adjusted cam chain based on the common motor video.

Fuel: Have checked the petcock. Good flow, no obstructions. My lines are transparent, so i can see that gas is getting into the carbs.

Carbs: Mikuni VM28. Both adjusted to mirror each other. The left runs like a champ, right refuses to fire like a non-champ.

Battery: Running an AGM battery. Charge is at about 75% and reading 12.4.

Im am kind of at a loss right now. You guys have helped a ton in the past. Was hoping someone would have an idea on what to check next. Hoping to be able to ride this spring.

Thanks in advance.
 

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Mikuni carbs ugh...... If you have spark then it's either air or fuel. check pilot jet, needle (sometimes they come out of seat and are loose) make sure slide cutaway is facing the right way half moon faces filters. good luck
 

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Put a fresh dry spark plug in that hole and see if it fires.
 

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Sometimes you can dry them off and get them to fire again, gas-fouled plugs are pretty hard to clean. You might try pulling the plug cap up about 1/4 inch, while it's running, the extra voltage built up by jumping the gap may be enough to get the plug to fire. Try running it with the petcock turned off to see if that right hand carb is flooding.
 

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Discussion Starter · #7 ·
Ok.

So, got one of those little tools you put in the middle of the coil wire between the spark plug and coil. I am getting a strong and consistent flash. So, thinking this is somehow an issue with the right carb. A new clean plug changed nothing.

Overhaul of the carb did not really show anything out of the ordinary. Think maybe adjusting the float height may be an issue? Ordered a good ruler I see people using for measuring float height.

One thing I have noticed that is odd. The bike will sometimes run at an ok idle for a few seconds, then the revs will skyrocket at so hard it feels like it would go to redline. Always hit the kill switch before it can get there though.

Could these things be in any way related?
 

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Discussion Starter · #9 ·
Mikuni carbs ugh...... If you have spark then it's either air or fuel. check pilot jet, needle (sometimes they come out of seat and are loose) make sure slide cutaway is facing the right way half moon faces filters. good luck

I think this was it. Seemed like the slide cut-away on the right carb was facing the wrong direction. Didnt understand what you meant till I watched a video on that very issue.

Ok, so now sounds like its running on both. But the RPM's are shooting to a scary high level on startup. Which, from what I can tell is most likely an idle screw setting. Will need to figure that bit out next.

Unfortunately only have about 30 minutes after work before it gets too dark to mess with the bike. Really hate not having a garage.
 
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