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Just got my 1st bike-CB750sc nighthawk, need advice on fixing

knickmar

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OK, so here goes,
I bought a 1982 cb750sc nighthawk a few months ago, and have now gotten to working on it. The garage I bought it from had the bike running with starter fluid before I bought it and said it was sitting for about 3 years, so the carbs were plugged. I bought a carb kit off of eBay, and replaced and cleaned as much as I could without taking the carbs off the racks to avoid headache. Last night I got them back on, and went to start it, and it wouldn't, so now I'm here trying to figure out what to do next. I did notice that there is a bit of fuel line or something missing from the carbs, but it looks nonessential. Instead of running the line from the tank to a t air regulator (that's what it looks like) and then to the carbs, the fuel line goes directly from the tank to the carbs. Any suggestions on what to do next?
 
OK, so here goes,
I bought a 1982 cb750sc nighthawk a few months ago, and have now gotten to working on it. The garage I bought it from had the bike running with starter fluid before I bought it and said it was sitting for about 3 years, so the carbs were plugged. I bought a carb kit off of eBay, and replaced and cleaned as much as I could without taking the carbs off the racks to avoid headache. Last night I got them back on, and went to start it, and it wouldn't, so now I'm here trying to figure out what to do next. I did notice that there is a bit of fuel line or something missing from the carbs, but it looks nonessential. Instead of running the line from the tank to a t air regulator (that's what it looks like) and then to the carbs, the fuel line goes directly from the tank to the carbs. Any suggestions on what to do next?


UPDATE: got it running last night, however, it is hard to start, I had it idling at 1k rpm, however, after about a minute it quit on me. Where should I go from here?
 
I don't know the nighthawk but most bikes I know have the fuel line going directly to the carbs. That air regulator might be some sort of emissions device. Does it have hoses that go to the crankcase or head? Quitting after a minute could be float levels...or clogging at the petcock.
 
Hmmm. Don't know but looks like an auto shutoff device that uses engine vacuum to keep the fuel line open. When vacuum is gone (engine off) the valve closes. Similar to the way a regulator works. If you are running directly that shouldn't matter.
 
I had a mechanic say that I might not have the floats set correctly, is there a place where there's a tutorial for this? I took the floats off and put on new float needles, and then just put the floats back on, assuming they would be still preset, I'm assuming I was wrong. I just need someone to tell me how to do it now, and I might get my bike on the road.
 
I found a guide on how to make your own float tool, and I've found the specs for the height, but once I get it on, how do I adjust the floats? Is there a screw somewhere? Anyone have a video or something around here?
 
On mine there is a metal tang that butts up against the float needles. You bend that (finger or screwdriver) until the floats are at the correct height. It usually takes a couple tries or more to zero in on the amount of bending needed.
 
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