There are little air passages on those carbs. Did you soak them?

Also, you say "kits"...what kits? Honda product, or...?

Another possibility might be holes in the diaphragms. You have to look at them with a back light.

 

Tony, I went through similar problems with my '85 Interstate. It ran OK below 3500 RPM and then would start missing. It is very frustrating. I made sure all of the carburetor passaways were clear by ultrasonic cleaning, blowing out with air all of the internal passageways and using a small steel guitar string through all of the jets. I replaced the air cutoff valve. There was nothing wrong with the secondary air system. In the end I discovered air leaks around the intake runner rubbers. I left the right bank intake clams loose and pinched one of the orings at the base of the
#4 carb. In the end I replaced the diaphragms, installed #112 jets, replaced the damaged oring and softened the rubber on the carb boots. This thread documents my experience. It is kind of long and the fix comes in near page 6. There is a video at the end. The #112 jets may not be necessary, but the bike runs the way it should.

http://www.goldwingfacts.com/forums...dwing-technical-forum/646521-jim-s-1985-gl1200i-diva-hits-road-ride-report.html

 

Before you condemn the carbs, check the fuel supply. Very seldom dirty carbs cause the bike to stall.

 

If i may add:
i changed all #35 pilot jet for #40 as recommander by many members,they are running lean a lot.

i double checked the float level and changed the gaz filter,even if tink it looks good,change it.

i used Johnson Evenrude Carburator cleaner and clened them using a toothbrush,,yes !
NEVER use brake cleaner ,it is too abrasive on copper or brass parts,

the pilot jet will make a lot of difference,
be careful with the diaframm also,i put a LITTLE bit of white grease on it so the cover will gently get colser and seal right.

it works for me and mine was stop 3 years .

gervais

 

I agree with GL and Jim. I had a couple of bikes that had the bad rubber mounts for the carbs. They would idle ok sometimes and it could backfire and shut off. At other times it might idle OK or not. My theory is if the manifold vacuum pulled the boots in it would be OK until the backfire. Then it could shut off or run bad for a bit. A poor mans way to test is to wrap the boots with 3 or 4 rounds of electrical tape. That will make the clamping force of the clamp greater. I have also ground down the stops on the clamps to increase the clamping force. Of course the correct way is to replace them. Spray some carb cleaner around the area and listen for a change or use water and watch for steam. Could use beer and listen for a belch too I think,

 

There are Special Oring's between the head and the intake adapter ,mine were corrupted because they changed them for "regular" rubber oring and these one are special for gaz and heat treatment so i baught the Honda Oem.

if you want to know if your intake boots are leaking,when you engine is idle,spray some brake cleaner at them,if your engine change rpm,run higher the boots is leaking.

Gef

 

Yes they were very expensive Honda kits and carbs were cleaned out well by soaking, running tip cleaning wires through all passages, spraying carb cleaning spray through all passages and blowing out with air. Diaphragms looked good, actually looked like they were new. New O-rings on the manifold to head surface and even replaced vacuum lines that seemed hard from heat.
Fuel pump seemed to be ok and I could feel it pulse about every two seconds while idling, fuel filter and supply hoses all replaced. I thought I covered all the bases but will check for air leaks around manifold and boots today before I take carbs off again. Jet size might be an issue, what would be a good recommendation for our elevation of average 4600 Ft.

 

If you live at a high elevation engines run richer. There air is less dense with oxygen.
Don't feel alone with the issues you are having. Most who attack those carbs have similar problems. When the bike was new it was the first years motorcycles had to meet EPA standards so the carbs were just rich enough to run. Check the boots with spray. I like carb cleaner. Take your time and check every possible place you can think of or see. The near microscopic holes by the throttle plate are very important and very difficult to get clean. Some have shimmed the needle to get more fuel in the engine. It seems so easy. You either are getting too much air or not enough fuel. Now go figure out which it is. Not easy at all.

 

Your no rookie I can tell, but I have to agree with the others check the intake boots first. When they sit little critters seem to chew on stuff as well. I would say O-rings since boots seldom leak even when cracking on the outside the inside is usually intact. From there I would check the diagrams again. Might check the Vacuum on each carb with a gauge as well it may narrow the problem down (just a thought). Might even hook it back up to your carb synchronizer and see if any thing changed or changes as it runs, or misses.

 

K&N air filter perchance?

 

Redwing can you explain the procedure for "shimming the needle". Is that the needle which is in the diaphragm tube under a plastic keeper with a small spring?

 

It is a fairly easy project and you do not have to take the carbs off. Just take out the 4 screws for the cover, Now look inside and find the screwdriver head. It turn 1/4 turn to release. Now take everything apart so you have the needle in your hand. Looks like a fancy nail. Go buy 4 of the skinniest o-rings that will fit on the needle and slide up as far as you can. Now put it back together. If you can't get the holder back on you bought o-rings that are too fat. :wink2: It is kind of a crutch but it has to richen fuel mixture. You are pulling the needle out of the jet just a little. So in a nutshell take the needle out. Slip on the o-ring (I use o-ring but steel shims will work) and put it back together. Test drive with air filter installed!

 

All you need to do is put a washer under the needle. Thickness of the washer will depend on how bad the issue is.

Mostly I don't think it works. It didn't for me.

Ken asked a question. What kind of air filter are you using?

 

hi,
go at any skidoo dealer,they exist these little washers and they have the same thickness,
remember 1-2 mm rising the needle will make a great difference in middle rpm.

carburator,carburation is a world ,,just like oil.

gervais

 

Hi Tony, Welcome to the forum.

You have done a great deal of work on those Carbs. - It is quite possible that you may not have a carb issue any more- You may have a Air Filter problem-
As Ken asked above... K&N air filter perchance? Occasionally we find K&N filters on goldwings but generally we hate them here.

It seems Goldwings don't like K&N air filters- If you have a K&N air filter I suggest you lay a 3/8" thick sheet of open cell foam over it and close the air box back up and see if your Lean issue is resolved completely or at least reduced. If the foam helps the problem then replace the K&N with an OEM filter.

 

Redwing thanks, will try o-ring tip this week and will report the results. Another project has pulled me away from getting this wing back on the road.

 

Tony, the question has been brought up several time and you keep ignoring it. What type (brand and style) of air filter are you using?

Also, I'd like more info on the kits you used.

 

I received a PM from Tony saying the kits and filter are from Honda.

 

I just recently R&R'd my carbs to replace the float valves. Started the bike, warmed it up and it ran great in the shop. Checked the carb sync (perfect) took it out on the street and it fell on it's face past 1/4 throttle. Used choke to get it to the fuel station and back home to look it over. Found a vacuum line had come undone. Replaced the vacuum hose and the problem was solved.

It appears that a vacuum leak as such made the slides (and needle jets) completely inoperable. Just a suggestion since you've gone deep into your carbs, an open vacuum hose may not be heard but will certainly cause what you have described.

 

Dennis
the "vacuum leak as such made the slides (and needle jets) completely inoperable"
normal,it is activated by the diafrag so if there is a lost of vacuum,the needle will not lift

gef

 

Just to close out this post, my GL1200 is fixed and running like a it should thanks to all the tips from this forum. I pulled the carbs again replaced the air cut off valve diaphragm and spring, added very small and just less than a MM washers to the main jets, then tuned the carbs. All of the running lean issues are gone. Now that bike is fixed my next project is to build a trike kit so I can ride while waiting to get my knees replaced. I will be doing this from scratch and will take pictures as I build the trike for the interest of anyone that wants to do the same.

 

Bravo Tony

Ride safe this season
Gervais

 

that will be awesome Tony,
I bookmark such things so that the threads can be found again