Tuning a rebuilt carb

[ericheath]

Just remove the bowl, and whatever is necessary to remove float valve. There can be a few things that can cause the float to hang open.

Make sure the float still floats in fuel.

Then look closely at the valve, check the movement of the spring loaded tip. Sometimes they freeze up. Soaking in carb cleaner often frees them up.

Then check the valve sealing area. Any lines/ridges means it’s bad. Look for evidence the valve is sticking in the sides.

Then the seat, look into it for wear marks or grooves. Some guys dress them with rubbing compound or even valve lapping compound to clean them using a q-tip. Go easy. I don’t remove the valve unless I have to. There is a screen under it but it sounds like it’s letting plenty through.

Randakk suggests looking at the tang on the float that the spring loaded tip rests on. Sometimes they wear a hole into the brass.

I yield the balance of my time to TrackT

[pidjones]

As in crap under it, float fowled, valve fouled, seat scratched - anything that keeps it from sealing. Always test a rebuilt set for floats sealing before installing. I use 91% isopropyl alcohol because the garage is in our basement. doesn't hurt rubber or plastic parts and any not removed will mix and burn.

makes sense. help a noobie: do you fully assemble both carbs on that side, then shoot thru the fuel inlet, or one at a time and/or partially assembled?

Hang an auxiliary fuel cell (I use an old Isopropyl bottle with a fitting and valve on it) with 91% alcohol (you can use gas, but I have a basment shop). Hook it up and place it about a meter higher than the carb rack (with rack out of the bike) and let the fluid from the tank fill the bowls until the floats rise and seal their valves. On yours, I guess you would then pull the bowls from that side and see which one seems to be the problem. I also place the carbs upside-down and pull a vacuum (MightyVac) on the fuel system to do a first check. This will usually show which is the culprit. If you have good hearing, you might be able to hear a leaky one when you pull vacuum.

[sphen]

I haven't posted in a while, bc i haven't worked on the bike in a while, but I did finally work with the carbs some more this weekend.

turns out one of the float valves was separated from its retainer, so that fuel inlet was wide open and quickly overflowed. Resolved.

I did note that while running it a while yesterday, a very small amount of gas is leaking elsewhere - best i can tell a small amount is getting thru the bowl gasket. I do recall that when i reassembled, i let the bowl gaskets dry and reshape overnight to let the swelling go dowm, but one of them in particular didnt go all the way back down this time, so i heated it a bit before i put it back. i may have an issue there....and get to pull the carbs for the 11th time...grrr. kinda getting frustrated with fueling - im ready to move on, especially since she seems to be running well.

oh, and i also noticed that the petcock is now leaking....not sure if they can be rebuilt, or better to just replace....it only leaks when "on"

[sphen]

concerning the petcock (1986 gl1200), is it rebuildable? it looks like the exact part is NLA, but there are some "catch-all" parts available for all years...apparently some have had better luck than others getting them to fit the 1200.

and, is it likely just a matter of o-rings? i may try to pull the petcock off later and see what i can get to.

[sphen]

also, what is considered 'normal' vibration levels for a 1200? poeple talk of goldwing smoothness, but i dont have anything to compare it too - but at idle, there is a noticeable rock in the bars/motor/frame.

[CYBORG]

also, what is considered 'normal' vibration levels for a 1200? poeple talk of goldwing smoothness, but i dont have anything to compare it too - but at idle, there is a noticeable rock in the bars/motor/frame.

mine doesn't vibrate at all. Idle is at 1000 RPM

[sphen]

hmmm interesting - thats what i thought. not sure whats up then....unless the motor mounts need to be tighter

[CYBORG]

Don't think it's the mounts. I have had 1200's running on the benchtop attached to nothing.......IF tunned right

[rcmatt007]

mine does not vibrate at all either.

[ericheath]

A bent rod on one of my 1200’s was enough to cause a vibration. Found it when a head gasket blew. I doubt you can check for that without pulling heads. Mine came after a hydro lock from a leaky float.

[sphen]

Don't think it's the mounts. I have had 1200's running on the benchtop attached to nothing.......IF tunned right

good point - im just getting up and running - havent sync'd anything yet

[sphen]

Back together today and seems to be leak free, other than the petcock. so its time to move forward - will come back to carb tuning when i get a manometer.

Concerning the petcock - i dont see a 1200 replacement on ebay, but i found one at saber cycle. it looks more like a universal part tho (for 1000, 1100, or 1200) - it has a reserve function which the 1200 doesnt have originally. not sure how it would line up - maybe just ignore the reserve, or either would work as "on"? https://www.saber-cycle.com/store/product626.html

the bolt spacing on mine is 43mm, which matches the description...

...or does anyone know of a rebuild kit for the 86 1200? this one says its for '87 https://www.ebay.com/itm/HONDA-FUEL-PET ... SwA2hex0WM

[flyin900]

[sphen]

...and the Saber Cycle petcock did indeed fit! no leaks now!

[sphen]

I had the carb rack out on the bench today and drained the bowls. I noted that there is more residual fuel on one side vs the other, particularly on cylinder 2. I assume that is due to float height tuning, but I’m sure I set them all pretty close to the same spec. Is it common to need to fine tune the float height?

You can see the difference in the two “pee stains” here:

95C948B2-BE87-4C7B-9A12-1A47D9CE83DD.jpeg