Topic: CB550 - ‘78 tank ‘76 carbs..Petcock?

[Jcop.550]

I have a ‘78 cb550 and got a set of ‘76 carbs I’m running. Problem is, there is only one outlet for a fuel line on the tank and the carbs require a petcock with 2 outlets.

Im currently running a “T” splitter but not getting enough fuel to #1&2 carbs. Anyone know where to get a petcock that fits a ‘78 tank with two fuel outputs? Having a difficult time finding one and some people say they don’t make any that fit. I can’t be the only one that has swapped ‘78 carbs for ‘76 carbs so any advice or help is greatly appreciated!!


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[TwoTired]

My 77 CB550 F came from factory with single outlet fuel tap and a T fitting to feed the four 069a carbs.  Always worked fine.

Might want to check your routing if you aren't getting fuel to all carbs.

Cheers,

[Jcop.550]

My 77 CB550 F came from factory with single outlet fuel tap and a T fitting to feed the four 069a carbs.  Always worked fine.

Might want to check your routing if you aren't getting fuel to all carbs.

Cheers,

That’s good to know, I will definitely check that. I was pretty skeptical about running a T. Wasn’t sure if it would get equal amounts of fuel running to both sides or not


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[seanbarney41]

My 77 CB550 F came from factory with single outlet fuel tap and a T fitting to feed the four 069a carbs.  Always worked fine.

Might want to check your routing if you aren't getting fuel to all carbs.

Cheers,

+1

[RAFster122s]

No filters in your lines, they can cause issues, petcock filter should be in good shape and sufficient to keep crap out of carbs, presumably your tank is in good shape. Routing as has been said is critical.

[flatlander]

all the above... and fuel line is originally 5.5mm.

[Stev-o]

I also have a "T" on one of my bikes, no issue.

Be sure all the fuel lines are running "downhill" as these carbs are gravity fed.

[jonda500]

"Anyone know where to get a petcock that fits a ‘78 tank with two fuel outputs?"
The '78 K tank has a smaller diameter petcock bung (I think it's 16mm) which is the same as the DOHC 450 twin, so you can use the dual output 450 petcock!
John