PS the PO probably backed out the fuel screws to compensate for dirty carbs. Now that you cleaned them the cylinders are getting too much fuel. I'm not familiar with your specific model, but on later models about 3 turns out is about right, I'd start there. Of course I could be wrong with all of this, but we have seen that issue before. Let us know the fix when you get it sorted out. Sent via BlackBerry by AT&T
-----Original Message----- From: "Allen Thomas" <[email protected]> Date: Wed, 29 Feb 2012 03:26:45 To: Nightwawk Lovers<[email protected]> Reply-To: [email protected] Subject: Re: [Nighthawk Lovers] 81 CB750C Carbs idling at 3500??? >From the factory Honda sets them so lean that if you touch the throttle the >engine will die. If you have to crack the throttle to get it to start then I'd >say it is way too rich. When it warms up does the exhaust start popping? (Rich >condition) IMHO you can't do an effective carb cleaning with out removing the >pilot screws. That could be why #2 isn't firing, its idle circuit sounds >clogged. +1 on doing a bench sync of the butterflies, it may not be perfect >but that will get the carbs close enough for it to run right once you get the >mixture correct. Sent via BlackBerry by AT&T -----Original Message----- From: Ralf Oehlerich <[email protected]> Sender: [email protected] Date: Tue, 28 Feb 2012 22:14:41 To: <[email protected]> Reply-To: [email protected] Subject: Re: [Nighthawk Lovers] 81 CB750C Carbs idling at 3500??? Worked on it more this afternoon. The trick with the sync screws did not help. Now the choke does nothing. I never touched air/fuel screws or idle jet. Now you need some throttle to start it and hold it for a while, then it idles again at about 2000+. Cylinder 2 is NOT getting hot still. I will pull the carbs again and try to sync the butterflies. I found an excellent article that discusses rebuilding these specific carbs. On Tue, Feb 28, 2012 at 7:55 PM, Allen Thomas <[email protected]> wrote: > ** > Has it ever run right to your knowledge. Did you do anything else done > besides cleaning the carbs? Did you count the turns on the fuel screws > before removing them? Will it start without the choke? > Sent via BlackBerry by AT&T > ------------------------------ > *From: *Ralf Oehlerich <[email protected]> > *Sender: *[email protected] > *Date: *Tue, 28 Feb 2012 03:17:39 -0500 > *To: *<[email protected]> > *ReplyTo: *[email protected] > *Subject: *[Nighthawk Lovers] 81 CB750C Carbs idling at 3500??? > > Working on a 81 CB750 custom and just cleaned the jets on the carbs. Put > everything back on the bike and she idles at 3500 rpm. Could that be a bad > fit/too much air? > Cables are free and idle screw is all the way out. Air box and filter are > in place. Plugs are NOT new. She runs fine, just WAY too high even with > choke off when cold. > > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nighthawk_lovers?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "Nighthawk Motorcycle Lovers!" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/nighthawk_lovers?hl=en. > -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en. -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en.
