bad air cutoff valves?

[Brian]

I have gone through all 6 carbs using the redeye rebuild kit. Rich gave directions on checking the air cutoff valves using the mityvac. Doing this revealed two bad valves. I never heard or experienced any deceleration symptoms or popping. Doing the research here a comment was posted about plugging the holes on the carb where this unit fits that these don't do much for our bikes. These little plastic valves are $50 bucks each without shipping. For this money they must be magic.

I was thinking about permanently plugging one of the plastic ports and reinstall them. Has anyone done this or should I just bite bullet and order new valves?

Suggestions?

[Chrisj CMA]

most people dont ever check them.  If you had not checked, you would have put it back together and probably continued to experience no troubles.  Id run it as is and think about fixing it if there is a problem some day.

[Brian]

most people dont ever check them.  If you had not checked, you would have put it back together and probably continued to experience no troubles.  Id run it as is and think about fixing it if there is a problem some day.

Going back reading how they work it probably is better to leave them as-is. The diaphragm holds the vacuum on both so I am not loosing anything there. If I install them like this I am planning to put them on the end carbs so separation would not be needed to replace them. You are right about checking these. I have no idea how long they have been like this.

[Bigwolf]

I had my carbs apart and checked the air cutoff valves at 25k on my 98 standard.  What I found was that all 6 valves would operate but 5 of the 6 would not hold vacuum on the diaphram.  I took one look at the price to replace them and disabled them all.  My bike runs well and I do not notice any decel popping.  I do have stock unmolested exhaust.

Bigwolf

[John Schmidt]

I've never checked mine, don't have any plans to do so. My exhaust is a low rumble, sounds very powerful, and when decelerating I get a bit of a burble. Sounds kinda neat actually, probably due to the type of exhaust mostly. Doesn't pop or sound like a "backfire" on decel, just gives off that low rumbling, burbling sound which makes it sound even more powerful....it's not loud. When coasting to a light in town, it has caused many bystanders to turn and look. The looks are usually accompanied by a smile and a nod of the head.

[Brian]

Well, I got the two valves working using carb cleaner and a couple of quick blasts of compressed air.
I did install them on the end carbs just in case. I plan to replace the OEM gas line tomorrow now that the smog crap is gone. I am moving the in-line filter down in there, where before it was up close to the manual tank valve right behind the coils.

[DrPitts70]

I know this is an old post but hoping some will still chime in.  I've recently acquired a 98 standard. It's got 12k miles and I understood the negatives of that when I purchased. It was running but definitely not running correctly.  I have pulled the carbs for a good cleaning. This took 4 times as I ended up having problems and ended up with 3 bad float valves. Bike is all OEM except for glasspack mod. Mainly meaning all internal carb jets are factory sizes so assume original. Also replaced air filter and plugs all OEM. Pilots set at 2.25 and synced. Checked for vacuum leaks and didn't find anything but one intake boot cockeyed but corrected. Idle is smoother than when purchased but still not right as there is a miss of some sort from left side. Now it will at least take thottle as before I had to "feather" it to rev it or take off. This miss is evident all the way up to about 2k+ RPM's. There is also a constant pop/ backfire from the left side any time I let off the throttle. I'm really excited with my purchase but am losing enthusiasm fast as I can't seem to cure this problem lol.
If it's the air cut off valves that would mean pulling the carbs AGAIN to test correct? I would like to understand better what is the cut off valve doing to create this problem. Is it adding too much air or gas all the time? Any other direction I should be looking?
Any help would be greatly appreciated.

[Skinhead]

I know this is an old post but hoping some will still chime in.  I've recently acquired a 98 standard. It's got 12k miles and I understood the negatives of that when I purchased. It was running but definitely not running correctly.  I have pulled the carbs for a good cleaning. This took 4 times as I ended up having problems and ended up with 3 bad float valves. Bike is all OEM except for glasspack mod. Mainly meaning all internal carb jets are factory sizes so assume original. Also replaced air filter and plugs all OEM. Pilots set at 2.25 and synced. Checked for vacuum leaks and didn't find anything but one intake boot cockeyed but corrected. Idle is smoother than when purchased but still not right as there is a miss of some sort from left side. Now it will at least take thottle as before I had to "feather" it to rev it or take off. This miss is evident all the way up to about 2k+ RPM's. There is also a constant pop/ backfire from the left side any time I let off the throttle. I'm really excited with my purchase but am losing enthusiasm fast as I can't seem to cure this problem lol.
If it's the air cut off valves that would mean pulling the carbs AGAIN to test correct? I would like to understand better what is the cut off valve doing to create this problem. Is it adding too much air or gas all the time? Any other direction I should be looking?
Any help would be greatly appreciated.

I think you still have clogged jets.  I could be wrong, but I doubt it is the ACVs causing the symptoms you described.