carburetor drain kit - water trap

bluebikerblan

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Don't know how many of you have thought about simpler more convenient ways of draining your carburetors of ethanol blended fuel and attendant goo, gum and crud between uses or while stored to keep them clean.....I used to say "keep everything filled with fuel to keep it clean and rust free". No more with ethanol blended fuels....poor aging, debris, phase separation, free water. Better to drain!

Here's a nice little system brought to us from the snowmobilers of the frozen north and Thunder Products:

http://www.thunderproducts.com/CarburetorDrainKit.htm

Hooks up real well with a threaded barb drilled and tapped into the Drain Plug but would be even better if I could find a M8 X 1.0 metric thread to 6mm tubing or hose adapter in brass to simply replace the hex head drain plug rather than tapping a smaller one into it 'piggy back' style.

Can anyone recommend a US source? Metric threaded (M8 x 1.0) barbed brass adapters (like the first hose adapter) seems quite hard to source. The second one is 1/4" x 28 and the last is the M8 x 1.0 OEM brass drain plug btw. Reward! Blue
 

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Here's the source spec for getting a package of copper sealing washers from Mc Master Carr if anyone's interested.....$12 for 50 as I recall. Needed for drain plugs or the 8mm adapter to tubing reference in previous post above.

Care to guess what the "reward" might be a handful of? I really didn't need 50. Best, Blue
 

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Just go grab some metric zerks, bonus they come in angled and 90 degree as well as straight. lightly drill the ball to remove it. I use them for float gauges too.

M8x1_90_Degree_Metric_Grease_Zerk_fitting.summ.jpg


Do I get the reward? Do I, huh, huh?
 
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Well technically you must be the winner ggg even though I knew they were available in M8 x 1.0 and I wondered but; I didn't really know that I could (or if so how to) make a tubing barb out of it.

Shoot me a pm with a mailing address if you will. Many thanks! Will throw in a couple other handy surprises too as I'm in your debt
re several other good tips. Hope you like them!
~~~~~~~~~~
Bonus on bonus....found the zerks for $ .32 cents apiece! Got to dig a little deeper into the goodie pile for Gary. Beats the heck out of a $5.00 adapter!

Don't know how many noticed the other tip you snuck in...."lightly drill the ball to remove it. I use them for float gauges too." Gary
 

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Great tip grepper like the "manometer" for synching, it makes me think this clear tubing fuel gauge it might be the best real float bowl level guide for setting float levels and checking the needle valve operation

Here's my favorite online "fittings and adapters" supplier btw if you're having trouble locating those M8 x 1.0 zerks to fit the drain plug threads.

http://fittingsandadapters.com/

http://fittingsandadapters.com/greaszerfinc.html

Very, very complete and handy....Blue
 
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Also great new source for everything "Zerk" and grease gun related.

http://saeproducts.com/brass-grease-fittings.html#8BRASS

Metric to English Adapters.............To fit the female BS 38 carb bowl drain plug hole...M8 x 1.0mm

http://saeproducts.com/grease-fitting-accessories.html#Metric

SAE Products Metric to English adapters convert any 1/4"-28 thread fitting to metric thread.
SAE Number FIG. A (MALE) B (FEMALE) C D E Alemite Lincoln
SAE-MEA6 5 6mm 1/4"-28 25/64" 13/64" 3/8" N/A N/A
SAE-MEA8 5 8mm 1/4"-28 25/64" 13/64" 3/8" N/A N/A
SAE-MEA10 5 10mm 1/4"-28 5/16". 13/64" 7/16" N/A N/A

Blue
 
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Blue- I'll look into this further: I just got my 16 year old son a 1981 Suzuki GS750 with 6k original miles. One of many things I wanted to do was sync the carbs, but there were no barbs on the carb manifolds. There was a screw, however, in each of the manifolds. A trip to the local Zuki dealer, and the parts guy found threaded, leave-in vacuum barbs. (Maybe $15 for the four) I don't remember the exact size, but I think it was 6mm x 1.0. I am wondering if they were made larger though. I will let ya know... -Mark
 
Thanks Mark, I've had those 6mm taps for some time as I use them to synch the carbs also in as much as I've eliminated the barbed vacuum lines and vacuum petcocks. btw with the BS 38 it's awkward to "leave them in the carb" as they do interfer with the throttle cable on the left side. I tried getting Motion Pro to source for M8 x 1.0 taps, since they make/supply the M5 and M6....no luck.

Metric to English Adapters

SAE Products Metric to English adapters convert any 1/4"-28 thread fitting to metric thread.
SAE Number FIG. A (MALE) B (FEMALE) C D E
SAE-MEA8 (8mm x 1.0mm male to 1/4"-28 female tubing barb 3/8" OD

So, I've ordered adapters from SAE and will screw the 1/4" x 28 barbed taps into them as a M8 barbed fuel tap unit.
Essentially the same thing as drilling and tapping a 1/4" x 28 thread into a 0EM M8 x 1 drain plug. ie combining the two parts pictured.
Still kind of pricey...so am working on sourcing in plastic probably Nylon or Acetal.

Back up plan is the M8mm x 1.0 grease zerks also ordered to trial as the (with removal of the ball check) to serve as the tapped fuel barb per GGGGary's prize winning suggestion. Prize pack now sent btw Gary. The Zerk route will be Much less expensive

Update 2/13: M8 x 1.0mm metric male threaded threaded brass barbed tubing adapters/connectors (hose tails) are available in the UK from a variety of suppliers at around the equivalent of $3.00 each. Seal with a copper washer ala the OEM float bowl drainplug.
Drilled out M8 x 1.0mm grease zerk (drilled out spring and ball) works pretty well but tougher to seal. Use Teflon tape as the Zerk seal method is via tapered thread.

Blue
 

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Posting examples of assembly of water traps via both the drilled out grease zerk method
and combined M8 and 1/4" tubing barb method. Glad to supply additional details if interested.

Works well to trap/separated water phase and borne crud from deteriorated ethanol/gasoline blended fluels before it carbureted.

Blue
 

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I think I like this idea. Trapping some of the crud before it gets to the jets and passages will prevent many problems.
Leo
 
Cool idea, I like it.

But I don't think you should tie them together, gas will overflow the low side carb on the side stand. or anytime it's sitting at an angle.
 
You're very right about that Gary. Of all the crudded up sets I've looked at, the left carb is the one (the lowest on the sidestand) is always the most crudded up, corroded, deposited and the one mostly likely to overflow etc. Seeing how the two carbs are connected anyway however it seems to be irrelevant as to whether the drains are singular or tied together. You know like....whichever needle valve doesn't seat. Other than that....it's the fluids pressure above the vent point level that causes the leaks....not the fluids (like those in the trap) below the vent level.

I tied them together when I was measuring the water phase collected per amount of ethanol fuel consumed.....at least that what I tried to do. They did work better hanging vertical, separate and isolated however. Spring clip on a plug works quick and easy as a drain tap.

How deep the trap is, whether the trap is long or short....is not too important but you must be alert to the meniscus level
of the water borne crud phase as it rises with build up; less it increases upwards beyond vision in the sight tube to the float bowl drain level. The space available below the carb tends to determine that. It is important that the trap be vertical as that's what actually traps the water ya know... like gravity and downhill.

Unfortunately, I'm not out much myself these days and so we need others for some road testing and data and feed back. The grease zerks are tough to seal well btw Gary in road use. Turns out the tapered threads seal of (grease zerk) against the parallel threads of the float bowl drain hole (even with Teflon tape) is not so hot. Moreover, I think a sharper tubing/hose barb or two and a longer stem may be needed for retention of the trap rather than that smooth round Zerk bubble. A couple have fallen off in use. Ideas?

Currently, awaiting some UK sourced M8 x 1.0mm tubing barbed adapters and am trying to re-thread some NPT threaded Nylon barbs to M8 x 1.0 with a rethreading die.....that's fun btw.

Anybody wants in to help with part sourcing, ideas, testing I'll be glad to work with you.

Dog Bunny's already helped a bunch, so has G's, 5twins, Rick at Oldskoolcarbs, Don James and old INXS too. More than they know!

Ultimately...either Nylon or Acetal fittings (adapter tubing barb) (plug) Tygon tubing (translucent works clear is better) to serve as a sight tube...which is needed btw! For now the pricey old Brass and copper seals have done most of the prototyping

Your first look at what settles to the bottom of your Water Trap will convince you that whatever it is you don't want it in your carbs. Ethanol blended gasoline fuels suck in carbureted vehicles especially where temperature and humidity cycles greatly. To say nothing of the multiple rubber part issues. Ethanol sucks water in as vapor and gasoline kicks it back out as liquid. Whatever likes polarity....water....better goes with it to the bottom. And that's the rest of the story....for today. Best, Blue

Try a trap and see for yourself.
 
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If your petcocks are working the way they should and shut off the fuel, the carbs won't over flow, so tieing them together won't matter.
Leo
 
An open connection between the float bowls is different than connecting the fuel lines. With a passage between the float bowls you will overflow the low carb if the bike is tilted. This will happen even with the engine running . Fuel will flow from the high bowl through your connecting line to the low bowl, overfilling it. The high bowl float valve will open attempting to return the fuel in it's bowl to the proper level, mayhem ensues.

I think the visible water trap idea is excellent, I just don't think they should be tied together.

In my climate fuel water separation is not a big deal, even the seldom used Farmall H with an atmospheric tank vent and a gascolator seldom needs draining/attention but you could throw a cat through the carb passages on that thing.
Leaving bikes sit for years with gas in the tank will fuggle the carbs ethanol or not.
 
Looking for ideas thanks. G's & Leo

It's sealing, space and capacity of the trap. There's a little less than 3" space for vertical placement which becomes about 2" of tube capacity with fittings (adapter, tubing barb, tube & plug) and getting the unit cost down and the sealing security up.

ie...from a practical point of view, there's no room or reason to tie the two traps together anyway. They work better just hanging vertically independently, not touching anything below the float bowl drain tap.

Best, Blue

Here's an excellent high tech source for plastic fittings btw. http://www.eldonjames.com/index.html
 
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I like the idea, really it's good one. Since you don't have much height, increasing the tube diameter should help. I really think you will end up custom machining or rethreading an an existing barbed adapter. M8x1.0 dies are cheap brass barb fitting are cheap. getting a full thread right to the "flange" will be the rub I think.
 
A good rethreading die which I have, takes the parallel threads right to each edge Gary so that's doable. The SAE adapter I used works a well with parallel threads the seal is accomplished between the two aluminum surfaces with a copper washer and works well. So does the 1/4" brass barb plastic washer to the adapter.

There are no sealing issues with the prototype method period. It's sealed, 3/8" ID clear, tough and durable. But parts cost is about $12 per trap.

The zerk route is well below that, under $5 as is the re-threaded NPT Nylon tubing adapter route. My own needs have been met but I'm not about to sit down and re-thread very many adapters whether Nylon or Brass. Moreover, M8 x 1.0 mm male metric threaded brass adapter to a 3/8" tubing barb as pictured below. They can be sourced from the UK at about $3.00 each. plus shipping etal. That essentially combines two of the prototype parts into one. For myself....were I riding that's what I'd use and the brass plug as well.
But that's just me I'm an old timer and just plain like oak, leather, brass, glass and xxx bestus.

PS...I use a acetal plug in operation but have just used the Drain plug (as pictured) wrapped with Teflon tape and clamped.
It can come in handy. A clamping hemostat works well as a petcock btw....even if you're not smoking.

Best, Blue
 

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