Anti Afterburn valve question


Information and questions on GL1200 Goldwings (1984-1987)
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harkgold
Posts: 147
Joined: Thu Nov 03, 2011 9:19 pm
Location: Des Moines, Iowa
Motorcycle: 1984 GL1200 Interstate

Anti Afterburn valve question

Postby harkgold » Thu Feb 02, 2012 4:52 pm



I have rebuilt the carbs on my '84 GL1200 Interstate and now I'm near ready to reassemble them, but before I do I would like to test the Anti After-Burn Valve. However, I cannot find anywhere in print where it explains how to do that. I can find instructions on how to remove and reinstall it but nothing on how to test it.
As a result, how would one know if it were even bad? The bike has almost 56,000 miles on it.

Thanks,

Harkgold :?:



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virgilmobile
Posts: 7649
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Anti Afterburn valve question

Postby virgilmobile » Thu Feb 02, 2012 5:05 pm

As I remember,there's not a whole lot to test.It either works or the diaphram is bad.When I did mine,I pulled it apart for inspection and a look see if everything was intact..kissed it and put it back on.
For the average user,it would be difficult to simulate all the vacuum and air flows needed to verify operation,so as long as the spring is there,the rubber is OK and it isn't contaminated don't loose sleep over it.
It's better to concentrate on the floats,slide function and the mods to improve the mixture problem.
Here's a link to my carb woes on my 84.And the fixes...viewtopic.php?f=5&t=9179
Oh I forgot,if the valve is inop,youll get a popping on decellerating

harkgold
Posts: 147
Joined: Thu Nov 03, 2011 9:19 pm
Location: Des Moines, Iowa
Motorcycle: 1984 GL1200 Interstate

Re: Anti Afterburn valve question

Postby harkgold » Fri Feb 03, 2012 11:56 am

virgilmobile wrote:As I remember,there's not a whole lot to test.It either works or the diaphram is bad.When I did mine,I pulled it apart for inspection and a look see if everything was intact..kissed it and put it back on.
For the average user,it would be difficult to simulate all the vacuum and air flows needed to verify operation,so as long as the spring is there,the rubber is OK and it isn't contaminated don't loose sleep over it.
It's better to concentrate on the floats,slide function and the mods to improve the mixture problem.
Here's a link to my carb woes on my 84.And the fixes...viewtopic.php?f=5&t=9179
Oh I forgot,if the valve is inop,youll get a popping on decellerating



Thanks alot Virgilmobile for the great information.

Yesterday, before I received any response, I did just as you suggested. I took the cover off and found the spring and diaphram to be in pristine like new condition. I then replaced all the hoses and made sure the metal hose tube on the cover was clear and put it back together. I also pulled the covers from the reed valve chamber and found the reeds to be in pristine clean and perfect condition.
This Gold Wing has only 56,000 miles on it and I knew the prior owner who bought it brand new in '84. He and his wife took several long distance vacation trips on it and it was seldom ridden in town. The bike has been from coast to coast, border to border, and into Canada and Alaska. So the vast majority of the miles on this bike are highway miles. This could explain why the inside of some of these components still look like new.

Thanks again!

Harkgold
:D

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virgilmobile
Posts: 7649
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Anti Afterburn valve question

Postby virgilmobile » Fri Feb 03, 2012 12:56 pm

Looks like you got it under control.Next step is to balance the carbs to the engine,or "SYNC" as it's called.
I fought with this for a while using mechanical gauges with poor results.
I finally came up with this design that works quick and is dead accurate.I've used it to sync the carbs on my 1100,1200 and the twin carb 1500.What a world of difference a good sync will do....viewtopic.php?f=16&t=8994

harkgold
Posts: 147
Joined: Thu Nov 03, 2011 9:19 pm
Location: Des Moines, Iowa
Motorcycle: 1984 GL1200 Interstate

Re: Anti Afterburn valve question

Postby harkgold » Fri Feb 03, 2012 5:06 pm

virgilmobile wrote:Looks like you got it under control.Next step is to balance the carbs to the engine,or "SYNC" as it's called.
I fought with this for a while using mechanical gauges with poor results.
I finally came up with this design that works quick and is dead accurate.I've used it to sync the carbs on my 1100,1200 and the twin carb 1500.What a world of difference a good sync will do....viewtopic.php?f=16&t=8994


Thanks again Virgilmobile!
Prior to syncing did you set your pilot screws to 3-1/2" turns out to start with?
Harkgold

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virgilmobile
Posts: 7649
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Anti Afterburn valve question

Postby virgilmobile » Fri Feb 03, 2012 5:49 pm

Yes,I don't yet have a tach that will show the 50rpm drop needed to adjust them so I left them all at 3 1/2 out.
Unless you've used the shop vacuum trick to test the slides,after it's running,stick a mirror at a angle into the plenum, snap the throttle and verify each slide pops up and back down

harkgold
Posts: 147
Joined: Thu Nov 03, 2011 9:19 pm
Location: Des Moines, Iowa
Motorcycle: 1984 GL1200 Interstate

Re: Anti Afterburn valve question

Postby harkgold » Sat Feb 04, 2012 8:52 pm

virgilmobile wrote:Yes,I don't yet have a tach that will show the 50rpm drop needed to adjust them so I left them all at 3 1/2 out.
Unless you've used the shop vacuum trick to test the slides,after it's running,stick a mirror at a angle into the plenum, snap the throttle and verify each slide pops up and back down


Thanks Virgilmobile for the tips. Yes, I did try the shop vac trick and they all work beautifully.
Harkgold :D

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firstwing
Posts: 37
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Location: Pittsburgh, PA
Motorcycle: 1985 GL1200A, 2006 Suzuki C50 Blvd.

Re: Anti Afterburn valve question

Postby firstwing » Thu Sep 27, 2012 10:10 pm

I've been following your posts. I'm having carb issues and am curious about the shop vac test for the vacuum slides. Also, I could use a "float adjustment for dummies" guide as well. I have the shop manual for 1985 GL 1200 A, but it's a little unclear to me. Any advise would be greatly appreciated. Thanks.

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virgilmobile
Posts: 7649
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Anti Afterburn valve question

Postby virgilmobile » Fri Sep 28, 2012 7:40 am

The floats....Set the carb assembly upright on 2 carbs,tilt them till the floats on the upper carbs tilt shut.This will not have enough pressure to compress the plunger in the needle valve.At that point,measure the distance from the carb casting to the bottom of the float. Flip them over and set the other ones.

Changing the measurement is done by bending the tang that makes contact with the needle.Very small adjustments.
Here's a bunch of pictures for the 1100 carbs.Use the same procedures.Also inspect the slide diaphragms for holes http://classicgoldwings.com/forum/viewtopic.php?p=2153
If you have a lean 1500-3000 rpm problem,lifting the needle in the slide a few thousands seems to help a bunch.Don't do this if the bike runs worse at 2500 rpm when you add a little 'choke'
Mine ran better with some choke at 2500 rpm,that's why I added the washer to the needle.

The shop vac test.....I just hold the hose from the running shop vacuum to each pipe that would bolt on the engine...as you open the throttle,air rushes through that carb and hopefully lifts the slide.
I make a mental note on how far and compare that to each carb one at a time.
I found on my 83 that one slide was sticking about 1/4 the way up.
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