1980 Carbs

[Jay60465]

Thread Jacking 1980 special Carb Help

Yes everything is out except the throttle plates. The tubes are the last thing before I have left before complete. I just want to be careful, I sprayed some more PB blaster and going to let it soak in overnight.
Since that pin does not hold anything in place, it is safe for me to continue tapping the tube with the dowel rod until it breaks free.

[Jay60465]

Thread Jacking 1980 special Carb Help

First of all I would like to thank everyone with the help they gave me earlier. My current situation is that the rack is installed and the bike runs after 20 years of sitting. So my next problem is that i have some overflow coming out of #3 and 4 carbs. After doing a search and reading some threads, I am guessing that you adjust the tab that sits above the float needle correct? What is the best way to bend that tab and the best way to measure the travel distance of the floats?

[mikubuilder]

fuel overflowing carbs usually is a sign of stuck float pin, I believe your SG has Viton tipped ones, you should probably replace them...also float height should be set before you mount carbs on your bike.
For plastic floats, I believe it's 23mm +/-1mm from lip where gasket sits(make sure you check both sides of the float), you can also restrict how low float drops, this will eliminate some hang ups.
One other thing you can do is to smooth out float pins, that helps with pivoting of the float

that's my .02

[GLoweVA]

First of all I would like to thank everyone with the help they gave me earlier. My current situation is that the rack is installed and the bike runs after 20 years of sitting. So my next problem is that i have some overflow coming out of #3 and 4 carbs. After doing a search and reading some threads, I am guessing that you adjust the tab that sits above the float needle correct? What is the best way to bend that tab and the best way to measure the travel distance of the floats?

Okay Jay, a couple of things.
Obviously you've got to pull the carbs back off the bike.
with the bowls off 3&4, check to make sure that the bowl gasket doesn't rub on the float. Another thing to check is make sure the float pivots/swings on the pin smoothly. (I had one hang up cause it was sticking on the pin)
The other thing is to make sure that the float doesn't drop too far and jam up on the post. There's a "L" shaped tab/tang that limits the back/open travel on the float. The floats don't have to open much to let fuel flow, so adjust those 'back' tabs so the float doesn't open too far.

Before you're ready to put it all back on the bike, hook up a fuel source and see if the floats will seal.
Another possibility is that the orings in the float valve assembly are leaking by.

Just noticed that Mikubuilder also replied with some of the same advice.

[Jay60465]

Thread Jacking 1980 special Carb Help

The float needles I have are the ones without the tab clips, so I believe they are not the viton model. They are new needles too, that came in the rebuild kit. I will for sure check that the gasket is not rubbing on the floats too. I have never adjusted floats before but when I installed the new kits all the floats moved free on the pins. I am just not sure on how much movement I should have on the floats.

[natemoen]

The float needles I have are the ones without the tab clips, so I believe they are not the viton model. They are new needles too, that came in the rebuild kit. I will for sure check that the gasket is not rubbing on the floats too. I have never adjusted floats before but when I installed the new kits all the floats moved free on the pins. I am just not sure on how much movement I should have on the floats.

We need to figure out what model carbs you have before we go much farther. Whether th bike runs or not, the carbs will need to be removed and cleaned. Get them off the bike, open them and get us some pics inside and out.

[GLoweVA]

I have never adjusted floats before but when I installed the new kits all the floats moved free on the pins. I am just not sure on how much movement I should have on the floats.

You should have at least checked the float height.
+1 on what nate said, We've got to know what kind of float you got to set the height. (early or later model carbs)(ie plastic/brass floats)
If the height is wrong, then the bowl may be filling up (and overflowing) before the float gets high enough to shut off the flow.

[Jay60465]

Thread Jacking 1980 special Carb Help

Yeah the carbs are 1979 models used on the early 80's specials,(brass floats, screw over pilot jet) but before I go any further. I forgot to mention I made eliminated the octopus on this bike. I used the diagram I found on a search in the modification section of the forum. Another thing I did was I used a an elevated tank from a 82 seca which only has 1 petcock and I tied in all four carbs together just to see if they work. I am not sure if that could have led to my leaking carb problem. Thanks in advance Jay

[Jay60465]

Thread Jacking 1980 special Carb Help

Yea I know i should have check the height. I am not sure on how to do that with these carbs. I can get my hands on a metric caliper to measure though. I couldn't find a good walk through using the search box on the forum.

[natemoen]

Yea I know i should have check the height. I am not sure on how to do that with these carbs. I can get my hands on a metric caliper to measure though. I couldn't find a good walk through using the search box on the forum.

On any caliper you have the jaw on the one end and then that strip of metal that come out the other end as you open it, that strip of metal is a depth gauge. You use that to measure the float height. You measure from to top (actually the bottom) of the float to the gasket mating surface with the gasket removed and the carbs upside down. Measure each float on the 4 pairs (so 8 measurements total).

With the brass floats you will set them at 25.7mm. Be very anal and precise here! Also, with the screw in style float need seats you will not have futon tipped needles, they will be all metal.

[Jay60465]

Thread Jacking 1980 special Carb Help

Awesome....what is the best way to bend the adjustment tab without messing any other part of the float up.

[GLoweVA]

For those lurkers that may be reading this, there's another way to 'measure' your float height without calipers.
Make yourself a go/no-go gage. I take a small piece of cardboard (or any other sutiable material) and using my ruler, measure off the required amount and put a ink/marker line there.
(Note: the required height is different for the type of float, sorry don't have those exact numbers in front of me)
Then you can set the cardboard "stick" next to the float and bend the float tab up or down as needed to get the bottom of the float to match up to the mark on the measuring stick.
Remember to NOT push the float down, just let it rest on the needle.
If one side of the float pair is higher than the other, you may need to 'twist' the float to get both floats to match the same height.

[GLoweVA]

Awesome....what is the best way to bend the adjustment tab without messing any other part of the float up.

Small flat head screwdriver is what I use. Just slide it under the tab and give it a slight bend, If needed, you can insert the screwdriver in the other way to unbend/bend it the other way.

[Jay60465]

Thread Jacking 1980 special Carb Help

Thank You, that is the way I wanted to do but didnt want to bend or break something.

[natemoen]

I would suggest taking the float off the carb to make adjustments that way you aren't using the float needle to pry against or anything else. I also use a screwdriver.