Topic: T-Fuel fitting Up or Down

[75750SS]

How should these be positioned, up or down

[mrbreeze]

I wondered the same thing when I did my carbs.I just went out and looked and mine are down. I think it is easier to plumb everything with them down but it seems to make more sense for them to be up.My bike is down for front-end rebuild right now so I think I will try to figure a way to make mine point up. I have already found a few other little things to fix while I'm at it. One is to make a brace to keep the rubber intakes from flexing when the throttle is opened. I just noticed that as I was taking my throttle cable off. Of course this only applies when you are running pod filters. As far as the fuel inlets....it works with them pointing down but I would think it would get the fuel a bit quicker without making the fuel travel uphill to get into the bowl.

[75750SS]

That's my thinking too.  I'm also using pods so plumbing it should be easier.
Thanks

[Raul CB750K1]

I used to have them facing down, and had additional inline filters. One day the bike wouldn't start, until I thought it could be the fuel not reaching to the bowls. Blowing inside the tank put enough pressure to overcome the curves of the fuel line.

Now I have then facing up, as the fuel line runs directly across those two holes in the linkage plate, so the fuel runs straight into the bowl. I know that Archimedes would say it doesn't matter as long as the tank is higher, but I've found trouble and therefore I put them up. If you don't have inline filters I would say there should be no difference.

[Spikeybike]

Archimedes no less .......(name dropper)

[75750SS]

Like this?  Harder to plumb this way.  Will have put the lines on before the carbs go back on the bike.

[mrbreeze]

What if you go over the vent tube and raise the tees a bit higher? I'll do mine later but if you figure out the best way,I'll probably copy you. I'm also using that clear plastic hose and I know it isn't as flexable as rubber. Maybe some angled metal tubing would help.

[75750SS]

Up and under it is!  Most direct route.  MrBreeze, use a little heat from a hair dryer and some needle nose pliers and the clear fuel line will go on easier.  I also put some heat shrink tubing over the fuel line where it passes through hole in the mounting bracket.  The holes felt a little rough on the front side of the bracket and I was worried about chafing.  The clear fuel line isn't as tough as the original (32 years, it was probably time to change them) rubber lines.

[Raul CB750K1]

Archimedes no less .......(name dropper)

Very true, my memory failed. Archimedes principle is about the buoyancy of objects inmerses in fluids. I was talking about Pascal principle and the communicating recipients, in which the height of the liquid tends to be equal in two containers that are connected. For that reason, no matter how many bends or curves does the fuel line have, the fuel should always reach the bowl because one of the containers -gas tank- has a higher level.


Now back to the original question, I have mine the same than in those pictures, but the tube goes up before the connecting vent tube -that is, almost vertical, and then goes to the plate hole.With a nose plier it's easy to put them even with the airbox on.

Raul

[mrbreeze]

Archimedes no less .......(name dropper)

Very true, my memory failed. Archimedes principle is about the buoyancy of objects inmerses in fluids. I was talking about Pascal principle and the communicating recipients, in which the height of the liquid tends to be equal in two containers that are connected. For that reason, no matter how many bends or curves does the fuel line have, the fuel should always reach the bowl because one of the containers -gas tank- has a higher level.


Now back to the original question, I have mine the same than in those pictures, but the tube goes up before the connecting vent tube -that is, almost vertical, and then goes to the plate hole.With a nose plier it's easy to put them even with the airbox on.

Raul

Yeah but what I'm saying is it will reach it a split second quicker without the bends. I also think that fuel line should go above the vent tubes...not below it. When these bikes were built,Honda used that cheesy skinny black rubber fuel line with the little joke looking clamps. It is our duty to upgrade the system!!!! I don't like the way the petcock outlet goes straight down for one thing and I would also like to devise a way to put a decent in-line filter before reaching the carbs. I will start designing a better mouse trap right away!!!! (along with other various things while my front end is off).

[Raul CB750K1]

The worst part of routing the fuel lines through the bracket holes is that there is no easy way to remove the gas tank, not even raise it a little bit. The lines inside the fuel tap are stuck solid and there is no space to use the fingers and pull them out. I once used a flat screwdriver to pry the line out... and ended up removing the brass tube from the petcock! That's when i decided to route the lines underneath the carbs, so there were more lenght to put inline filters, and then had trouble with the gas flow because it seemed that an aire bubble remained in the inline filter and then the gas would not fall by gravity.

[mrbreeze]

I hear you Raul!!!! So I guess you,me, or someone is going to have to step up to the plate and design something better (build a better mouse trap so to speak!!). I posted on this subject a couple of years ago and didn't get any takers. As of late...I'm not as in of much as a hurry to go ride as I am to make things work better. I'm sure if we all put our heads together,we will come up with something that works.

[Raul CB750K1]

I found a quick-release fitting that could be used to release the fuel line without removing it from either the petcock or the t-fitting. But 30 euros each seemd way too expensive to me...


http://www.louis.de/_20782e7b5147043ad75cb2fcef36580f5c/?media=katpdf&topic=artnr&artnr=10007932

[clarkjh]

I found a quick-release fitting that could be used to release the fuel line without removing it from either the petcock or the t-fitting. But 30 euros each seemd way too expensive to me...


http://www.louis.de/_20782e7b5147043ad75cb2fcef36580f5c/?media=katpdf&topic=artnr&artnr=10007932

Anybody translate?  I like the idea, is there a built in replacable filter?

James

[jabbadeznuts]

I found a quick-release fitting that could be used to release the fuel line without removing it from either the petcock or the t-fitting. But 30 euros each seemd way too expensive to me...


http://www.louis.de/_20782e7b5147043ad75cb2fcef36580f5c/?media=katpdf&topic=artnr&artnr=10007932

Those quick disconnects are fantastic. They don't have an inline filter though. Retail is something ~$20, at least at the shop I work at.