Topic: 78 cb550k carb help needed

[chiefum]

I picked up a project 1978 cb550k and could use some guidance. The previous owner told me that someone came to test drive the bike and when they came back, it was pouring gas out of the overflow of the carbs. I purchased the bike and brought it home via a trailer. I took it for a short ride around the neighborhood and it didn't seem to be leaking any fuel. However when driving and pulling in the clutch to down shift, the bike will stall. I think I have attempted to try the clear tube method, I'm not sure if it was done correctly,  but I'll attach a picture. Any help on what the next steps should be would be greatly appreciated,  I am pretty new to working on bikes, but I am pretty handy working on cars. Thanks in advance for any guidance. 

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[flatlander]

carbs overflowing can be due to some debris being stuck in the float needles so they don't close.
i'd start by checking the fuel delivery system and make sure it is spotless clean: tank, petckock, fuel lines all the way down to the carbs.
only once that is sorted, move on to the carbs if.problems still.persist.

[chiefum]

carbs overflowing can be due to some debris being stuck in the float needles so they don't close.
i'd start by checking the fuel delivery system and make sure it is spotless clean: tank, petckock, fuel lines all the way down to the carbs.
only once that is sorted, move on to the carbs if.problems still.persist.

There was some debris when I tried the clear tube method. I will try cleaning everything. Thank you.

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[Scott S]

 Looks like your float heights are all over the place.

[chiefum]

Yes, they appear to be.  I think I'll try to read up on the pd46c and see if I feel comfortable working on them.

[flatlander]

yes indeed but get everything nice and clean first as your reading might be influenced by dirt blocking things and then you just keep chasing your tail working on the carbs without fixing the "source".

originally, there was a fuel filter "sock" inside the tank. check the partslist to see what i mean. while at it, see if it's still there and intact, if not then replace it. it does a great job and works better than inline filters.

[Scott S]

Some observations:

 1: Never trust a P.O.
 2: Do the 3,000 mile tune up before chasing carb tuning (valve and cam chain adjustment, points/timing, plugs, etc.). Carbs come last.
 3: You have what appears to be velocity stacks. The jetting could be causing your stalling issues.
 4: If the tank is clean and internal petcock filter is good, no need for external filters.
 5: The float heights shown in your pic will certainly cause tuning/running issues.
 6: Expect to deal with jetting and tuning with those open stacks.

[chiefum]

Some observations:

 1: Never trust a P.O.
 2: Do the 3,000 mile tune up before chasing carb tuning (valve and cam chain adjustment, points/timing, plugs, etc.). Carbs come last.
 3: You have what appears to be velocity stacks. The jetting could be causing your stalling issues.
 4: If the tank is clean and internal petcock filter is good, no need for external filters.
 5: The float heights shown in your pic will certainly cause tuning/running issues.
 6: Expect to deal with jetting and tuning with those open stacks.

Good advice. I've done valve and cam chain adjustment, just have to check the points and timing yet.