carb questions

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superrigger · Tue Sep 25, 2007 7:40 am

Just purcahsed a 1982 Honda CB750SC Nighthawk (17K miles) it has 4:1 exhuast & K&N filter, there are to vac hoes from the carbs that went to the air box that are plugged off, should that be? I runs pretty desent but will pop every once in awhile, I've cleaned the carbs, changed spark plugs, above 2k it seems to run great, any ideas would be greatly appreciated. Thanks

mgdavis · #2 Unread post by **mgdavis** » Tue Sep 25, 2007 7:57 am

The pop is an indication that your bike is running lean. The lean condition is being caused by your aftermarket intake and exhaust, which are able to flow more air than the stock pieces. You probably need to re-jet your carbs, bigger jets for more fuel, to bring your air/fuel mix back to where it should be.
I don't know about your vacuum lines.

superrigger · Wed Sep 26, 2007 4:12 am

Well it seems if you sit back a look at the bike sometimes it's right in front of you, the exhuast the previous owner had installed was only about hand tight, after reinstalling the bike runs alot better & all the sputtering has come to a end. That's the 1st time I've had that kind of problem, it's usually the carbs 99% of the time. Thanks for all your help & safe riding! Troy