Slew of Carb Problems

[Icculus88]

Hello. Bike is 79 GS750 e. I have a few other posts on here bout my carb rebuild.

The bike ran well last summer, then began to lose power, then only ran on 3 , then 2, then 1. Then just flat out struggled to idle on 1 cylinder. I rebuilt and did not touch the floats and now almost all carbs are overflowing. Can i take these in to be measured? I don't have a micrometer.

Also, i rebuilt carbs and the connectors were leaking. I put them back together with Z1 fuel connectors, and the o-rings didn't make it. So I soaked the original connectors in fuel and put the carbs back together again and they were not snug enough. Any suggestions?

Now that this has taken weeks while i was in school and moving. My number 4 carb has this white residue on the inside and along the rims. I dont know if this mysterious white stuff is in the internals. But it is only in # 4. It is powdery and looks as if a liquid dried and then molded in the carb. Ideas?

Also, now that i have had the tank off and in weird positions (leaning upright) for a few months. The petcock started to leak.

So i am asking for any help. I am assuming these problems are separate and not related. Please let me know if you can help!

Very Grateful,

-Pat

[Steve]

I rebuilt and did not touch the floats and now almost all carbs are overflowing. Can i take these in to be measured? I don't have a micrometer.

How can you (properly) "rebuild" the carbs and not touch the floats?

You have to remove them to take out the float valves so you can change their o-rings.

A caliper will work better than a micrometer, but even that just gets you into the ballpark. The best checking device is actualy severely under-utilized. A clear tube attached to a modified drain screw will show you the actual fuel level in the float bowl, which is better than simply setting the float height.

Also, i rebuilt carbs and the connectors were leaking. I put them back together with Z1 fuel connectors, and the o-rings didn't make it. So I soaked the original connectors in fuel and put the carbs back together again and they were not snug enough. Any suggestions?

"The o-rings didn't make it." ??? Huh?

Not sure what you were hoping to accomplish by soaking the original connectors in fuel. When the fuel dries out, what is going to happen? In normal use, only the inside of the connector gets wet, so soaking the whole connector is an exercise in futility.

If your original connectors are the ones that have what looks like shrink-wrap over a couple of o-rings on the T, try wrapping a few layers of Teflon tape over them, then sliding them into place.

Also, now that i have had the tank off and in weird positions (leaning upright) for a few months. The petcock started to leak.

Not sure that the "weird" position had anything to do with that. Is it leaking from the mounting area or from the inside? There is a gasket (probably an o-ring type) between the gasket and the tank, as well as sealing washers under the bolts that hold it to the tank. If it is dry outside the petcock, check the little o-ring that turns the gas off. It is attached to the plunger on the diaphragm. If the o-ring looks OK, make sure that the area where it seats also looks OK. There are "rebuild kits" available, but the success rate with them tends to be about 10-15%. You might be better off getting a new petcock, then not have to worry about it for another 30+ years.

.

[Big T]

How do you know your power loss is caused by the carbs?

Sounds like failing points to me

[Nessism]

Or tight valves.

Time to do some maintenance, or sell the bike and get something newer.

[platinum2]

white powder is corrosion , it sounds like it hasnt ran on that carb in a long time

get the right o rings, check the float needles to see if they have a groove wore in them, replace if so, use a small ruler to check the float height, then blow air through each float inlet to see if they shut off, i use a piece of new hose on the fuel inlets, turn carbs upside down and listen to the seat area, see hot it goes, also check the pilot jets make sure there clean