Topic: CB550 Ran out of gas and now won't idle/start HELP

[bamshackalacka]

Hello Forum,

Today I was riding my 75 CB550F around town, high 80s, and it died on me at as I was leaving a stop light, I believe I ran out of gas so I rolled her to a gas station that was luckily really close and filled up with 85 and let me and the bike cool off a little. I tried to start the bike back up and after a little bit of throttle turning and button pressing the bike came back to life and as soon as I let go of the throttle it died, I let it sit another couple of minutes and same thing happened and now it will only turn over, until I drained the battery.

Can someone please help me deduce a problem, besides a dead battery now, so I can get my bike out of the ice rink parking lot. also yes the fuel and ignition were turned on.

Thanks guys

[evinrude7]

if you pull the fuel line off the carbs and turn the petcock to on does fuel flow? 

[TwoTired]

What country are you in?

In the states there is E85 which is 85 % alcohol.  Don't think bike will run on that.

We have regular 87 octane that runs fine.

[evinrude7]

What country are you in?

In the states there is E85 which is 85 % alcohol.  Don't think bike will run on that.

We have regular 87 octane that runs fine.

yes +1

[bamshackalacka]

confirmed that I put in regular old 87 in the tank and not E85 thankfully and I started to go over the fuel lines by removing the tank, spilling gas everywhere, and making sure the petcocks were working. I did notice that the gas cap was not on properly. I put the tank back on, spilling less gas this time, and rehooked up the fuel lines and ran some gas through to make sure gas was moving in the system and low and behold the bike started with only minor throttle input. I did notice after a quick test drive that the bike only idles if choke is all the one on even after bike is warmed up, any idea what that is about?

[CBGhia]

Sounds like you sucked something up into the idle jets.   When you ran it out of gas, debris may have made it down into the carbs.  I would first check to make sure that you are getting fuel in all the bowls.  use the little drain screw on each one to check.

[flybox1]

Start with a thorough carb cleaning,  a complete tuneup, including valve adjustment and timing/advance, and a vacuum sync.

[Spanner 1]

Rust from the tank sucked into carbs, blocking idle/slow jets. Carbs gonna have to come off, no short cut for this  !

[bamshackalacka]

The PO did say he took the carbs to a HD shop so they could have messed up jetting, but still points to pulling the carbs. There are in line filter between tank and carbs. Ill post pics when I pull the carbs.

carb rebuild kit bought.

Thanks Guys!

[Deltarider]

There are in line filter between tank and carbs.

There's the culprit probably. I had nothing but bad experiences with those. What I hated most, problems were intermittent. If standard petcock filter is still there, there's no need for any extra filters. Is yours a F or a K model?

[pjlogue]

If your fuel line ingested air and you have a hump in your fuel line or a filter you can have an air lock in your fuel line.  You can turn off the fuel valve, drain your float bowls and then open your gas cap and blow into the tank to pressurize it while opening the fuel valve.  That should push any air caught in your line out. 

-P.

[bamshackalacka]

it is a 75 550F, Ill try and see if I can remove any air and check the inline filters before I pull the whole carbs

[bamshackalacka]

If I need new jets, no idea what size is in the bike now, what would you suggest I get for a stock airbox and MAC 4-1 with baffle exhaust?

[Deltarider]

Standard.

[TwoTired]

The mac 4to1 was first offered to replace the rotted out 4to4s.  So they work best with jetting found on bikes that had 4to4s.  The was mostly 022a in the states.  If your F model still has the 069a carbs, change the main jet to 100, and find slide needles for a set of 022a carbs. Also use 022a needle position setting.

Fyi:
If you had the stock exhaust on it before, you can expect the bike to now get worse gas mileage.

Cheers,

[bamshackalacka]

Thank you TwoTired and friends!

How much power loss should I expect when my bike is running as lean as it is currently, I took it around after checking valve clearances and it pulls good  to about 4K-5K then keeps screaming but doesn't accelerate as hard and has trouble getting past 50mph in 3rd, which obviously makes sense cus lack of fuel. Is this all due to the carbs or could this be some other issue? also looked at fuel lines and looks like gas is running fine through them but I think I will pull the inline filters and see how it runs without them this weekend.

You guys are the best!