Topic: CB550 idles but stalls under load

[Rookie]

I recently went through a 1974 CB550K.  When I attempted a test ride, engine dies as soon as I let out the clutch.  It will struggle down slight incline. Won't go 2 feet on a flat.  Seems like it's very lean.  I don't think it has a side stand switch. Carbs have been cleaned. The main jet is correct.  Any suggestions?

[jaytee-nz]

At low speeds, the main jet is not in use. Where are your air/fuel mixture screws set at ?
Use the search function on this site to check carb settings - there is a ton of information available.

[Rookie]

one and a half turns

[Scott S]

 Are you sure it's running on all four? Try the spit test on the exhaust pipes, near the head.

[Sano]

I had the same symptom.  Check that the spark advance mechanism is moving freely. I put too thick a grease under the points cam lobe and it would not move freely enough to advance properly.

[Rookie]

Finally got her running.  In retrospect, the problem was timing.  Trying my best with static timing I still had it set way in advance.  It seems you can be too careful setting static timing.  Finally got her running well enough for a friend to put a strobe on her.  Way better now.  Also, with the old pipes and and pods she was running very lean.  I put in a 130 secondary main jet (book calls for 100) which seemed to shift it over to rich.  still messing with her but I'm on the down hill.  On a side note: jets are hard to find.  It seems covid has shut down many Japanese factories and many are out of stock.