Parts n' More manual petcock review

[Coyote]

Well it's here. Let me start by saying this was hard to photograph. Too much reflection with the flash and not really ample light otherwise.
First off, You won't have to worry about clearance around it. the whole thing is about 1 1/2 square. It looks tiny because it is. Run is at 6, off at 9 and reserve 12 o'clock. It came with everything you see. The adapter plate is 3/8 thick and recessed for the included 6mm allen bolts. When the petcock is screwed into the adapter up to the o-ring on the pipe thread, it does not protrude. That o-ring might seal it, but I'll be wrapping it with teflon tape to be sure. The ad said it had 3 outlets and one block off plug..One of the 3 outlets is in the front! It's not a brass plug, it's a screw with a fiber washer(lower left on the face). I can't tell if it's made out of cast aluminum or flash chrome plated steel. I put on my digital kitchen scale and it weighed i at 4.9 oz.
The holes in the outlet fittings are small (.152). I may have to use both 90' outlets to feed my GS1000. Never can tell though, 1 might keep up. The feed tube that makes you switch to reserve is way too tall in my book. A full 2 3/4 measured up from the o-ring. I would cut it down, but it's all enclosed in a very well made filter screen. I'll be on reserve when I still have half a tank. But the GS has a fuel gauge that is pretty accurate. All of it is made in Taiwan. I'll report more when I install it and see how it is. The selection lever is stiff, but it moves very smoothly.
There seems to be some concern over there being no prime position. Not needed. When you flip it to on, it is the same as prime. It's easy to forget there is no vacuum involved.

[Coyote]

I don't have large hands. I wear a medium glove.

[Alan H]

Looks a nice bit of kit. The cheap asian stuff has really improved in quality.

[Coyote]

It's not a Pingle and does not carry a Pingle price tag. The whole mess including shipping was just under $50. It actually appears to be well made. I did find one thing strange though. I was playing with it and testing it with my mouth. It takes more lung pressure to draw through air in the reserve position. The run position offers no resistance at all.. Still yet I don't think it will be a problem. I just wish I could get in there and chop about 70% off that reserve tube. It's way too tall. It's actually the 'ON' tube. When the fuel drops below that, you need to switch to reserve. The reserve hole is flush with the top of the pipe thread. Both are enclosed by the same screen.

[Coyote]

Maybe that's just fine after all. I just pulled the OEM petcock and it's riser tube is 2 3/8. The new petcock is going to fit just fine with no mods to the tank hole.

First and serious problem. I pulled the straight fitting and the block off plug to put the right angle fittings on. The threads weren't 'keyed' to tighten in a certain spot. One points straight up and the other faces forward. Swapping them makes no difference. IDEAS? The threads on the fittings are straight cut, not tapered. Both need to point straight back.

[Cliff]

Use a thinner sealing washer or sand down the ones you have.

[Coyote]

That was my first thought Cliff. Believe it or not, those fiber sealing washers are captured!. I tried to force them into the threads and screw them off. No way. They are just too tight. The only way I can get them off is to cut them. Something in my head is telling me not to do that. Not yet anyway. I still have the single straight barb I can use, but I don't think the hole is large enough to feed 4 hungry VM26's. That's the whole reason I wanted to convert to 2 feed lines. I guess I'll go ahead and try the single feed. The feed hole on the OEM petcock is .210 compared to .152 on this manual.
You know the old rule of thumb. Doubling the diameter of a pipe increases it's capacity by 4 times.

[yeadon_m]

Then add a thin washer - anything to tune it to lock up when pointed where you choose.
Mike

[Coyote]

I guess. Threads re insanely short. Not much room to add anything. PLUS, they are 7mm! Thread length with washer on is only 4.8 mm. (.190). Nice finish though

[Coyote]

Opinions plz. Do you think if I coated the threads with JB Weld. screwed the fittings in to where I want them, it would hold?

[Coyote]

Forget the whole mess. Look at the size of the reserve hole. Can't be more than 2.5mm (.1). That would never feed 4 carbs. This explains why it's harder to draw air through on reserve. I wasted my money.

[tricky1962]

Don't be too hasty, I think sufficient will flow through there.

I took some wild stabs at numbers for you here

http://www.efunda.com/formulae/fluids/c ... r.cfm#calc" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

I assumed a 1cm feed into a 2.5mm diameter orifice, 1mm Hg pressure drop (naff all) with a fluid density of 0.8g/cc (about right) and left the flow coefficient alone

That gives 45 imperial gallons an hour. Seems high, but maybe if you are really nailing it you could get through fuel at that rate before it seizes. (Can't do proper smilies)

I reckon it will work for you

[Coyote]

Thanks tricky! I knew there had to be equations out there somewhere. Maybe another math wizard can verify your findings. 45 imp gallons seems a bit much. I can see where it would start out real fast and slow down considerably as the head pressure drops.

[tricky1962]

Seemed too high for me too, so have just double checked. I go the density wrong, I had it much too low. Correcting for that and allowing for the fact that your tank is probably at least 3" above the float bowls, so the pressure drop is greater, gives a more reasonable 4 gallons an hour.

You could perhaps bodge it into the bottom of a can, fill it with water and time how long it takes to empty, to put your mind at rest.

[Coyote]

You could perhaps bodge it into the bottom of a can, fill it with water and time how long it takes to empty, to put your mind at rest.

I thought about that and decided it would be easier to go the other way. Putting a hose on the output barb and running the test fluid backward through the petcock should give me the same result. No?