Topic: Some questions about the clear tube method

[Scott S]

 I know what the clear tube method is, and I know how to adjust and measure float height.
 
 But how are you guys holding or supporting the carbs? Do you have some sort of rack? Just holding them by hand? Are you using gas or water or ??
 It just seems like it could be a messy, smelly, fiddly affair.

 Is there a trick, or is it just that way?

[mystic_1]

Because gas and water have different densities, the floats will float differently if you use water.  Use gas.

Do the test with the carbs mounted on the bike.  If this is not an option, whip up a little stand using a 2x4 and some PVC couplers or sections of PVC pipe.

mystic_1

[calj737]

With the prevalence of ethanol fuel, I think they're both pretty close anymore (fuel and water) 

[mystic_1]

Nah, water is denser than either gasoline or ethanol.  This is why it sinks to the bottom of the tank if it's present in the gas.

mystic_1

[calj737]

Nah, water is denser than either gasoline or ethanol.  This is why it sinks to the bottom of the tank if it's present in the gas.

mystic_1

I was being facetious there, Mr Serious 

[spanners]

Hi there,   I used some old 1/2 inch thick chipboard wooden sheet,  roughly sketched around the carbs then cut out so the float bowls dropped through.   (you can see in the pic I got the holes wrong the first time :-)  I then just angled the wood a bit between some metal garden chairs to relate to a similar position to the bike.

I purchased a low cost Aux 1ltr plastic fuel tank from ebay and strung that up for the test.  Between adjusting float level I drained the fuel back each time into the aux bottle  This aux fuel tank has actually proved invaluable for many test on the bike since then with the tank off. 

[mystic_1]

Nah, water is denser than either gasoline or ethanol.  This is why it sinks to the bottom of the tank if it's present in the gas.

mystic_1

I was being facetious there, Mr Serious 

Heh   I know that, I probably should have added "heh " to my post in acknowledgement of that.

[seanbarney41]

I can't give you anything too specific because I am less familiar with 550 carbs, but I usually make a quicky tab that can be screwed to the rack so you can clamp it in a  bench vice...sucks that all bikes don't have the 750's quick release float bowl clips, yes gas is messy and stinky get used to it if you are not already and this is not a job for the living room.  You will really only need a fairly small amount of gas.  I have often just used a short piece of hose with a funnel attached to fill the carbs.  Learn how to re-assemble the float needle, float, and pivot pin without inverting the carbs.  You will get good at this fast as you are going to be doing it 50 bazillion times.  If you are lucky, you have nice, original float parts that have never been adjusted and the clear tube will reveal spot on fuel levels

[riverfever]

Scott...as much as I dislike removing the rack of carbs, I prefer to do it off the bike. I used some 2x4 and a bench vise (kind of sandwiched the carbs in between the wood in the vise) and this held them solid and level for me. I removed the tank from the bike and placed it up on some boxes and used longer sections of hose to feed fuel to the carbs. I'd check #1, remove the float, adjust, reinstall, try again and repeat until I got it where I wanted it. I left the bowl gasket off until I was done and then do one last check with it back on. It is a bit messy and I did grow very tired of the smell of gas but it was just easier for me. Each time I had to redo a float, I'd drain the fuel into a section of Coke can and then dump it so I had as little fuel all over the floor as possible. Once in a while I'd get a leak somewhere but it wasn't bad.

[Duanob]

I always clear tube with the carbs on the bike. If a float gets stuck when installing them you will never know.

[flybox1]

I always clear tube with the carbs on the bike. If a float gets stuck when installing them you will never know.

+1
I have a 1 gallon tupperware bin that the carbs sit nicely on.  Theyre perfectly upright, and gives me easy access to the bowls while testing.
To combat floats sticking when the carbs go back on, turn on the fuel slowly, and give the stay plate a few soft wraps with a rubber mallet before they completely fill.

[riverfever]

Duanob...if a float were to get stuck while reinstalling the rack, wouldn't it be obvious with fuel spilling out the overflow? Please don't read that line as me being a smart a$$. It's a legit question.

Flybox...I'm having a hard time picturing your setup. Do you unbolt the rack from the head and then rest them on your bin?