Steve Saunders Goldwing Forums banner

1 - 20 of 29 Posts

·
Registered
Joined
·
121 Posts
Discussion Starter #1
Had the carbs apart over the winter for cleaning. End of winter, I ran and balanced them with no problems. Rode the bike three or four times and it ran well. Last week, however, it idled rough as the day wore on. I assumed it was the idle mix screws and figured to re-tune the carbs today. In the process, I found the throttle spring was detached and #3 plug wire was in bad shape. Fixed all that - spring, plug wire and idle mix - hooked up the CarbTune to balance them and...#4 carb consistently moves the mercury (?) to the top of the scale. It pegs there and does not come down to earth.



I switched the hoses around to make sure it's not the manometer, tubes, etc. It's not any of that. The #4 carb runs to the top of the scale no matter what configuration is used.


It's strange, to me, because it had balanced several weeks ago with no issues. Now, it's unreadable. What's going on with #4 please?
 

·
Official "Cheeky Plonker"
Joined
·
1,185 Posts
I'm more used to gauges than a manometer so are you saying that you have a positive pressure at the intake of #4 instead of a vacuum, or do you mean it just stays at zero psig?
 

·
Registered
Joined
·
121 Posts
Discussion Starter #3
It's not zero, so yes it's positive pressure. In terms of a dial gauge like a speedometer, it's pegged at 120 mph...if you catch my drift.
 

·
Official "Cheeky Plonker"
Joined
·
1,185 Posts
I kinda hoped you wouldn't say that, because I can't think of any other way for that to be highly positive than a problem with the intake valve on that cylinder. If you take the pipe off of that intake, can you feel anything coming out?

Sucks I know, but maybe some others will chime in with some better and less expensive ideas.
 

·
Official "Cheeky Plonker"
Joined
·
1,185 Posts
If you take the pipe off of that intake, can you feel anything coming out?
 

·
Registered
Joined
·
121 Posts
Discussion Starter #9
Thanks Dennis. That's what I thought but wasn't sure.
Need to do a compression test before doing much else. Reading doesn't turn up any info on why one gauge would spike like that.
 

·
Administrator
Joined
·
24,402 Posts
#4 is the base carb on a 1200, all others synch off it. Turn the base idle screw in to get the vacuum to come down, the idle will go up, then start adjusting the others to match #4.
 

·
Official "Cheeky Plonker"
Joined
·
1,185 Posts
He's referring to the exhaust head pipes.
No, No, No. The test pipe from the manometer to the intake, if you remove it, can you feel pressure outwards? Like, blowing against your hand.
 

·
Administrator
Joined
·
21,865 Posts
The threads on those little plates can be stripped pretty easily. Also, the little spring can get dislodged. Are you sure that when you are turning the adjustment screw it is actually changing the setting?
 

·
Registered
Joined
·
121 Posts
Discussion Starter #14
Understood, Dave...I'll give that a shot.


Quick (cold, dry, left the primary wires connected) compression test gave me #4 at 140psi, #2 at 145psi, #1 at 165 psi and #3 at 160 psi. Not sure what spec is on the GL1200s but 120 is good to go on my other bikes.


Calling it quits for today. Will get back to it tomorrow. Thanks for the help...will let you know how it goes tomorrow.
 

·
Registered
Joined
·
121 Posts
Discussion Starter #15
#4 is the base carb on a 1200, all others synch off it. Turn the base idle screw in to get the vacuum to come down, the idle will go up, then start adjusting the others to match #4.

I didn't see all the responses when I said that I'd be quitting for the night. Sorry about that. I'll work my way through them now.



I got that #4 is the base carb. As such, I thought #4 has no adjustment so I don't know what you mean by "base idle screw." Here's what I know/have worked with - four idle mixture screws, three carburetor adjusting screws (one screw each on carb 1, carb 2 and carb 3), and the throttle stop screw.
 

·
Administrator
Joined
·
24,402 Posts
I got that #4 is the base carb. As such, I thought #4 has no adjustment so I don't know what you mean by "base idle screw." Here's what I know/have worked with - four idle mixture screws, three carburetor adjusting screws (one screw each on carb 1, carb 2 and carb 3), and the throttle stop screw.
The large idle stop screw in the rear center of the carbs, where the cables connect.
 

·
Registered
Joined
·
121 Posts
Discussion Starter #19
Thanks again. Just want to make sure that I understand...even though I've been riding for just over fifty years, I wouldn't consider myself even a shade tree mechanic.
 
1 - 20 of 29 Posts
Top