New guy with CB550 eager to learn

[VagabondBlues]

Hey all,

New guy here. Been lurking for a while, but figured it was time to introduce myself. I'm fairly new to bikes but eager to learn. This is my CB550 -- has been a blast to learn to ride on. Have some carb issues now and I'm a total newb, so I'll be asking for some advice and help from the community here.

 

[adventurco]

Welcome to DTT. That's one hell of a nice looking machine you've got there. What kind of carb issues have you got going on? If there's been gas in it for a while or the tank is dirty inside one of your jets could be clogged. My personal practice is to thoroughly clean the carbs on any "new" motorcycle that I get, since they can be finicky and it's typically the first thing that causes these old girls to run poorly.


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[VagabondBlues]

It's actually my second bike -- I also have a '76 CL360 Scrambler that I've had for a few years to tinker around with and learn. When an acquaintance was selling his CB I jumped at the chance to have a bike in great condition for a cheap price.

When the bike is cold I adjust the idle screw to run at around 1,800 - 2,000 rpm -- for some reason it won't idle lower than that without dying. After it warms up I'm able to turn the screw out a bit. Both at cold and warm, the bike idles inconsistently. The problem now is that the bike lags quite a bit when I hit the throttle, and sometimes stalls/chugs along.

I have not cleaned the carbs yet as I've put it off in fears of not knowing how to put it back together properly.

 

[adventurco]

when you say idle screw you mean the idle speed screw - the big one you can turn with your fingers or the A/F mix screws? either way you shouldn't be messing with them unless the bikes nice and warm. put all the A/F screws where the manual says, usually 1.25-1.5 turns out, let her warm up and adjust the idle speed to about 1,200 rpm. Thats the sweet spot. If its idling high then you might have a vacuum leak letting some extra air in..

a quick easy test you can use is to fire her up and let her run for about 15-20 seconds, touch each header with the back of your hand (quick tap, don't burn yourself)...they should all warm up the same. if you got one or two that are much hotter than the others/warming up fast, start there.

 

[VagabondBlues]

Yes, the idle speed screw. I have not touched the A/F mix screws or the four individual adjust screws. I hope to have some time this weekend to work on it and touch the headers as per your suggestion. Maybe I'll post a video of it idling to give you a better idea.