carb will not adjust??


Information and questions on GL1200 Goldwings (1984-1987)
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jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

carb will not adjust??

Postby jtimgrant » Tue Jul 29, 2014 10:56 am



My 87 has runs rich at idle since I got it a year ago. The carbs has been cleaned multiple times. Compressed air and spray cleaner used. Jets are CLEAN. Air and cleaner passes easily through all ports/channels. But the pilot screw on number 4 carb has no effect at all except when turned out past 3 turns at which point it begins to lope due to loading up making it even richer. The other three pilot screws has a very noticeable effect when shut off. Where could the extra gas be coming from? The manual suggests a blocked AIR jet. None are that I can tell. Also, I have pulled the enrichers. They all seem to be working properly. I have blown through the idle jet and air passes easily out the hole in the carb throat. When the pilot screw is shut off air does not pass through the hole in the carb throat so the pilot screw is doing its job. But turned completely off the pilot screw has no effect on the motor at all. Also, if I pull the vacuum line off number 4 while running the engine runs better which tells me the cyl is rich. My nose tells me too!

Also, one of the jets is PRESSED IN. What does this jet control? Enrichers? the manual says the slow jet screws in and is the one with the very small hole. That is also the one that provides fuel to the pilot screw according to the compressed air flow.

Thanks,

t



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virgilmobile
Posts: 7660
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: carb will not adjust??

Postby virgilmobile » Tue Jul 29, 2014 4:03 pm

Past 3 turns is normal...The starting point is 3.5 turns out...It's possible that the others are too tight and 4 is supplying most of the fuel...
Set them all at 3.5,warm it up and then turn each one out till you hear/see the 50 rpm drop..this is where each carb is set.
You will need to adjust the idle after each adjustment..
As soon as you hear/see the rpm start to drop when adjusting the idle mix screw OUT...stop and move to the next carb....
Do sync the carbs first prior to the idle down adjustments.

There is a point when adjusting the idle mix screw in when it squeezes off the fuel and that cylinder starts to miss...as it's turned out the rpm will pick up...as it's turned out further,it will "load up"(too much fuel) and the rpm will start to drop...you want to set the screw right at the point where it starts to drop...

jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

Re: carb will not adjust??

Postby jtimgrant » Tue Jul 29, 2014 4:12 pm

Hi Virgil. According to my Honda manual the starting point for the 87 is 1 3/4 turns. Am I missing something?

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virgilmobile
Posts: 7660
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: carb will not adjust??

Postby virgilmobile » Tue Jul 29, 2014 4:23 pm

Probably not...
I'm going from memory about the turns out...I think that may have been on my 84...
Remember that this is a "starting point"... with further adjustments needed.

Whatever...the idea is the same tho...turn um in till they quit...turn um out till they cough then back um back up to the happy spot...right at the drop in idle..This is the perfect idle mixture for that cylinder.
If there left lean,that cylinder will run hot...The fuel also lubes and cools the upper cylinder so it's important that the mixture and sync be on the nats ass...
So to speak....

jtimgrant
Posts: 77
Joined: Sat May 25, 2013 7:24 am
Location: Greensboro NC.
Motorcycle: 1987 GL1200 Aspencade

Re: carb will not adjust??

Postby jtimgrant » Tue Jul 29, 2014 7:48 pm

Virgil, here is what I did. Following your settings I wound up at around 3 3/4 on each one. I'm almost afraid to say this but here goes . . . it worked! No more loping at idle. No rich smell on decel. I've only rode it a few miles so I may be jumping the gun but it sure runs better than it has since I had it. I've had this problem for a year. Set like this all the carbs respond to the pilot screws which is something I have not experienced before so I'm going to tweak it a bit from this point and put it back together.

Thanks for your help.

PS. My wife just said "It will probably blow up now." Nothing like optimism.

t

User avatar
virgilmobile
Posts: 7660
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: carb will not adjust??

Postby virgilmobile » Tue Jul 29, 2014 8:34 pm

Your on the right track.Dont adjust the mix screws any more till you have the carbs synced.
By the way,try to keep the idle at 1000 rpm during the sync process.Thats where the bike really needs to be smooth.




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