First Project: Newb questions, 1977 CB550

[jdmfrontin]

Hey guys i recently picked up a 1977 CB550 running for $650. It's my first project so any tips and suggestions would be appreciated. Don't know anything about these bikes but i plan on learning a lot. Hopefully a cafe build, we'll see. first, i wanna get the motor running better. When riding, it gets to about 4-5k and then starts to sputter and bog. I don't know anything about carbs, does that mean they need cleaning? re-synced? or does it sound like i have some other major problem? the power band is pretty smooth up til it plateaus at 5k.

 

[yorkie350]

welcome on board mate yeah i would be looking to strip clean carbs then resync them are u running original airbox or have u got pods they make a big difference also check ya plugs see wot there like look forward to seing more of ya thread good luck

 

[MotorbikeBruno]

Carbs are usually a culprit, and at that rpm, it would be a main jet issue, a sync issue, needle height, float height or possibly even timing (advancer having issues)

Does it have pods, or stock airbox? If stock, verify that there is an airfilter, and if there is, if it looks original, throw it in the garbage and get a new one, the paper elements fuse together over time and don't really let much air through them. Also check for mouse nests

And as said above, check your timing to make sure it's good. I'm assuming you are using new gas, and that the gas lines flow freely?

Pics too!

 

[jdmfrontin]

It doesnt have an airbox on at all. I will definitely check the plugs and replace them. here are some pics 8

 

[yorkie350]

She looks sweet mate ya tank looks real straight bonus for no big dinks in it no airbox i would be looking at a full strip n clean for ya carbs she's gonna be a great project to start good luck were here if ya need moral if not always technical support

 

[VonYinzer]

You're running the bike with no air filters? That's a very quick way to destroy an engine bud.

 

[MotorbikeBruno]

You're running the bike with no air filters? That's a very quick way to destroy an engine bud.

I'll have to agree with VonYinzer here JDM. As you are new, we won't give you too much hell for it though Just don't ride it around like that!

The airbox/filters regulates the flow of air to the carburetors, too much air will make your bike run lean (white plugs), too little and you will be running rich (black sooty plugs). If you know you are going to be running pod filters, or some other method, you have to change how much fuel the carburetors get, thus you change the jetting inside the carbs. Do some searches on CB550 jetting or info, and you'll find quite a few different setups. My last cb550 used 110 main jet, and didn't really like the crappy pods I had on it (later I switched them out). Remember that cheap pods generally don't filter out as much crap as they should, and again "generally" cause jetting headaches.

 

[jdmfrontin]

Thanks alot for the help guys! The bikes not registered yet, so the issues i'm having are mainly just riding it around my neighborhood and noting the way it behaves. I haven't really been riding around with the bike running the way it is.

I think i'm going to clean up the outside of the motor as much i can and then hopefully repaint it. The carbs, i think i'll try to disassemble and reassemble with now gaskets and jets. and then put everything back together with new pod filters and see how she rides.

I'll be back to bug you guys again, i'm sure. ;D

 

[yorkie350]

Always here fella i aint no guru but can lend an ear at least got some engine pics after i cleaned my motor gave me a buzz to see the difference 8) keeps ya goin when ya hit the wall haha

 

[sxecafe]

Looks mighty fine.