[joshe46]

Hello all,
Like the title states I am at a complete loss. My 1974 cb200 will start to misfire very badly/ dying/ stuttering until it all together shuts off after the bike is warm.
And it still does this even after a full top end rebuild. New gaskets, cleaned head, lapped valves, honed cylinders, and new piston rings.
Not only that but,
New condenser, new ignition points, new plugs, new battery, new ignition coils.
Rebuild carbs and brand new petcock.
What on earth could cause this issue? A bad ignition coil even though new?

 

[J-T]

Does it do this just idling? After riding a few miles?

 

[joshe46]

Does it do this just idling? After riding a few miles?

Only after riding a few miles. But idle sometimes likes to fumble and shut off.

 

[doode]

What do your plugs look like?
What brand points you using?

It's fine cold and has issues when warm? You have an intake leak? Re torque the head? Floats not functioning?

 

[joshe46]

What do your plugs look like?
What brand points you using?

It's fine cold and has issues when warm? You have an intake leak? Re torque the head? Floats not functioning?

Plugs were literally put in yesterday. I have yet to check them. I’ll check the head nuts . Intake leak is possible, the carb gaskets to head are old, and the ignition points are oem brand, they may be reproduction.

 

[doode]

Check the plugs in case they show rich or lean.

 

[Simo]

Is the Tank venting correctly? Pop the lid open as it starts to stumble and see If it fixes it. if so clean the cap vent

 

[Alex jb]

When you said the carbs were re-built, did they get ultrasonically cleaned? Or all the little transfers and jets poked and wiggled with a strand of bicycle cable?

Did you use new fuel line?


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[joshe46]

Is the Tank venting correctly? Pop the lid open as it starts to stumble and see If it fixes it. if so clean the cap vent

Will do that! Wouldn’t it be nice if it’s that simple.

 

[joshe46]

When you said the carbs were re-built, did they get ultrasonically cleaned? Or all the little transfers and jets poked and wiggled with a strand of bicycle cable?

Did you use new fuel line?


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The carbs were not ultrasonically cleaned. I used carb cleaning sticks, and a lot of carb cleaner. The fuel lines are new.

 

[Polish]

Try playing with the choke when it does it, that would indicate to lean.

 

[joshe46]

Try playing with the choke when it does it, that would indicate to lean.

Great idea! I never thought of that! Will do. Thank you