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Author Topic: Fuel filter/distributor.  (Read 613 times)

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Offline toglhot

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Fuel filter/distributor.
« on: May 21, 2024, 03:59:08 PM »
I made a fuel distributor a while back, its function was to level the fuel when the level in the tank dipped below the level of the tunnel and also to neaten things up. ,I had two online filters feeding fuel into the distributor.

The filters just kept cracking and leaking, so I decided on a combined fuel filter/distributor and this is what I came up with. The unit sits between the manifolds I made a while bike and is mounted in rubber grommets on a bracket attached to the cam chain tensioner.

The filter is sintered bronze and the body 6061. The bore is 18mm at the top to seat the filter and O ring, then expanded out to 23mm. There are three 6mm brass barbs pressed into the lower section, two for inlets for fuel, the third for purging debris. The top cap is retained by two M4 screws and is a push fit over the lower body, an O ring sits in a recess around the filter for sealing the top cap to the lower body.

Two 8mm brass barbs were pressed into the top cap and they feed the carbs via short fuel hoses. The cap is drilled 10mm underneath leading to a 5mm cross drilling which lead to the two brass barbs.
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Offline Don R

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Re: Fuel filter/distributor.
« Reply #1 on: May 22, 2024, 07:00:59 PM »
 The popular opinion here is that fuel will airlock if a line goes down, then up, and down again. Does it? 
  I've also had issue with inline filters on gravity feed lines plugging up, I believe it's caused by a gel from moisture and alcohol, hopefully the brass filter doesn't do that.
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Offline toglhot

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Re: Fuel filter/distributor.
« Reply #2 on: May 23, 2024, 01:05:49 AM »
Cars must have terrible problems with airlocks then:  The lines go up, down, up, down, around, left, right, up, down then into the carb.
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Offline newday777

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Re: Fuel filter/distributor.
« Reply #3 on: May 23, 2024, 01:52:52 AM »
Quote from: toglhot on May 23, 2024, 01:05:49 AM
Cars must have terrible problems with airlocks then:  The lines go up, down, up, down, around, left, right, up, down then into the carb.
They don't have gravity feed fuel. They have fuel pumps. And yes the old cars did get fuel delivery problems 🙄
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Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline toglhot

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Re: Fuel filter/distributor.
« Reply #4 on: May 23, 2024, 05:05:31 AM »
I never had fuel delivery problems with old cars, I am also old and had plenty of even older cars.
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Offline Don R

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Re: Fuel filter/distributor.
« Reply #5 on: May 29, 2024, 12:57:27 PM »
 We used to put wooden clothes pins on old car's fuel lines to prevent vapor lock. I still don't know how or why it worked.
  To be clear, I didn't say I'm a believer in the "only downhill" fuel line theory I meant that it's a popular theory here. My brother always ran his fuel lines down below the carbs, through filters and back up. I always thought at times, a little carb vacuum survives in spite of the bowl vent and helps pull the fuel into the float valve.
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 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.

Offline seanbarney41

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Re: Fuel filter/distributor.
« Reply #6 on: May 29, 2024, 10:34:20 PM »
Look at Honda's factory fuel line routing on the cb350k's and cl350's ...it loops down below the bowl and then goes up to the inlet nipple...but I don't think those little twins are as capable of sucking the bowl dry with a fast run through the gear box.

I notice your installed pic is showing a Yamaha xs650
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Offline toglhot

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Re: Fuel filter/distributor.
« Reply #7 on: May 31, 2024, 03:23:14 PM »
Yep 74 TX650.  Before and after.
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