Honda Spree and Elite 50 Forums

Those look promising, but this:

"With the Dubro Bolt-on Pressure Fitting you can pressurize your fuel tank. Simply drill a hole for 6-32" threads in the muffler and install the fitting."

is a little scary. Hot exhaust gasses and possible sparks venting into a fuel tank.

RC cars go BOOM

You pressurize gas tanks with crankcase pressure not exhaust gases. Pressurized gas tanks are not new, the outboard motor industry did it back in the 1940's and 50's. They then got smart and went to fuel pumps driven by the same crankcase pressure (and vacuum pulses). There is a one way valve in that fittin that only allows pressure thru.

Quick trip to the hobby store landed a set of the DuBro pressure fittings. From top to bottom we have 6-32, 8-32 and 10-32 all priced @ $1.90 ea. Compare the barb to the carb bowl drain (Edit: carb bowl drain barb for size reference), and pick your size. Note on the inset photo, these fittings are just straight through threaded barbs - no check valve.

Bear45-70 wrote:You pressurize gas tanks with crankcase pressure not exhaust gases. Pressurized gas tanks are not new, the outboard motor industry did it back in the...

I don't know why - but muffler pressure still gets used in the hobby world. Folks used crankcase pressurized fuel systems in model engines decades ago too. Here's a link showing a muffler pressurized fuel system in an RC car.
http://hubpages.com/hub/How-to-Start-your-RC-Car

mousewheels wrote:[ quote="Bear45-70"]You pressurize gas tanks with crankcase pressure not exhaust gases. Pressurized gas tanks are not new, the outboard motor industry did it back in the...

I don't know why - but muffler pressure still gets used in the hobby world. Folks used crankcase pressurized fuel systems in model engines decades ago too. Here's a link showing a muffler pressurized fuel system in an RC car.
http://hubpages.com/hub/How-to-Start-your-RC-Car[/quote]

That's because no one is riding on them and if they catch fire, it endangers no one.

Greetings:

Z50R_Blank have both been searching for those. Uhh, Whut's a "Hobby Store?" Any National chains with parts like barbs online? The ones Z had looked like they were made for our carbs, even a tiny O-ring seal under the barb.

Wheelman-111 wrote:Z50R_Blank have both been searching for those. Uhh, Whut's a "Hobby Store?" Any National chains with parts like barbs online? The ones Z had looked like they were made for our carbs, even a tiny O-ring seal under the barb.

Back up there - I mentioned the type of hobby shop (RC models) and put in online link earlier in the thread we are in. In the post you reference, I was trying to help the online shopping guys select the size they wanted. Also to show the fitting is a straight through barb - no internal check valve.
http://www.hondaspree.net/phpBB3/viewto ... 97#p112797

So one of the above mentioned (and shown fittings), a drill and tap, and I can run oil and petcock on my intake correct?

So one of the above mentioned (and shown fittings), a drill and tap, and I can run oil and petcock on my intake correct?

Yes - drill/tap, thread sealant/locker is a good idea. As Wheelman said early in the thread, separate tap for oil & vacuum.

Just got back from my lunch break and a reasonably short drive to my "local" hobby store (12 miles and across State lines, but hey what we wont do for our scoots right). They only had one fitting in stock that Mr. Mouse posted about above, but I now own one 6-32 Du-Bro fitting just like shown above. They guy at the store was nice we chatted for a while about what I was doing and when I said that was all I needed he said just give me $1 and call it good. Not that the $0.90 savings is that much as compaired to Mousewheels, but a nice guy none the less.

This adventure out also swung me close enough to go slightly out of my way to my local Honda-san. Picked up a couple more bottles of oil, and they happened to have cone-o-stone fuel filters as well so I picked up a few to have on hand.

Now I have to try and find 6-32 tap... I am certain my tap set doesn't go that small.

Greetings:

Is the barb 1/8" outer diameter? You don't want any looseness on the vac line - or oil, for that matter.

The outside of the barb portion is closer to 3/16, the smaller tube portion is 1/8

Check out the tubing fit. If a bigger one looks better, pm me and I'll mail it out tonight, least we can do after that flywheel puller detour.
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Went looking for specs on the DuBro fitting, but their online catalog provides none. The part numbers may be helpful. Found a right angle fitting with a washer (probably still not the one Wheelman's looking for). They give no size, other than its a 4mm thread. Visually, the barb is approx in the correct range - if I recall, the oil line is 3.5mm.

Right angle 4mm fitting + duBro fittings
http://search.ehobbies.com/search?query ... ng&x=0&y=0

Why do that, just drill out your fuel petcock out.I don't trust it working right.I use a plastic in line shut off for a lawnmower.