puffing sound coming from carbs

[seestheday]

I have recently started to hear a puffing sound that increases in frequency with revs coming from my right side carbs.  Spraying starter fluid confirms a vacuum leak, and the #3 plug is reading very rich.  I'll be doing the wintergreen trick to try to fix the vacuum leak.

Anything else I should be looking for?

Engine does not have a high idle and does not have an issue returning to idle.

Bike is a DOHC
Main jet is 75 (68 is stock) 110 secondary jets (105 stock).  4-1 exhaust.
Air/fuel screw is 1.25 turns out.

Bike runs really smoothly other than the puffing sound.  Throttle response is great, with a really smooth curve, and other plugs read ideal.

[seestheday]

nobody?

[Lucky 1]

Did you check to make sure the vacuum ports for syncing the carbs is not missing a screw?

[seestheday]

Yep, those screws are all in, but I'll check to make sure they're tight and not the source of the vacuum leak.

Sent from my BlackBerry device on the Rogers Wireless Network

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From: "Lucky 1 [via Honda CB750'S]" <[hidden email]>

Date: Tue, 9 Oct 2012 14:31:05 -0700 (PDT)

To: seestheday<[hidden email]>

Subject: Re: puffing sound coming from carbs

Did you check to make sure the vacuum ports for syncing the carbs is not missing a screw?

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[LukeM]

Hmm...
Let's hope this isn't the case, but what about a bad vacuum diaphragm on carb #3?  I understand you won't find out until you pull the carb(s) apart. They can be pretty pricey, and not repairable if memory serves.

Also, would it help to put little neoprene o-rings on the sync vacuum screws?  A bent washer or a bent screw could lead to a vacuum leak.

Just some thoughts.
Luke M