Well, it finally happened. After 38 years, my vacuum operated petcock decided to retire. Now that's pretty good, and I certainly can't complain about the longevity of the part. However.....I am going to convert the petcock over to a gravity feed unit. I don't need any 'why do that', or 'vacuum is the way to go', or anything else. Gravity feed is what I'm going to do.
So, that being said, I know some members have done this before. What petcock did you use?
I heard pingle was the best from 'Eye' but I have done alright with petcocks from 'DRAG I would put in an inline fuel filter though,
got it at NAPA auto parts clear plastic and you can see the filter element. BTW though is 'EYE' still around?
Yes, Eye is still around. Pingle has a very good rep. I have one on my Harley. But I can't justify spending that kind of money on an old Suzuki. A simple gravity feed petcock like the Jap bikes had back in the 70's will do just fine. That way I can clean the fuel 'trap' at the bottom, plus keep an eye on the extra filter, as you suggested. I think I may have found one. 44 mm a bolt hole to bolt hole, with the center fitting. Comes off an old Kawa. But I don't think the Suzy will mind.
Not sure the flow rate is as important as their advertising suggests, for a street bike, anyway. Racing is another question.
Say your bike gets 30mpg at 60mph; that is just over 4 ounces per minute of fuel flow. Double the speed and halve the mpg, though, and you get about 17 ounces per minute, so enhanced fuel flow may be helpful.
On my dyno winning 96 inch Harley big twins, the engines flowed so much fuel that the stock petcock was inadequate and at high load and rpm's, the engine would 'starve' and it would act like it was running out of gas and that's exactly what was happening:surprise:
1. Drain the tank and remove the fuel valve.
2. Plug the vacuum hole wherever it may be (carb)...you won't be using it again.
3. Gut the fuel valve...take out all of the internals so the fuel flows through not matter what.
4. Install an inline shut off valve and fuel filter; cheap wherever small engines are sold.
Your reserve option will be gone, but no big deal just watch that fuel gauge.
Have some gasket material on hand, you'll probably need it.
PS> I ran a hose from the carb vac port out to where it could be easily accessed. On cold days, I unplug the hose, shoot in a little starting fluid, bike fires fast, then plug the hole. Starting fluid really helps with carbed bikes in cold weather and injecting a shot right into the cylinders through that vacuum port works great and saves a ton of wear on your starter/battery.
For my 1987 Suzuki LS650 Savage, the fix was simple, replacement mechanical petcock from a 1990's Yamaha Raptor ATV. You may have to do a little searching for your model, but an answer is out there and it doesn't have to cost you an arm and a leg and definitely cheaper than the OEM one. Previously I replaced it with an OEM one, but with Ethanol in the fuel, it lasted only several years.
Drag petcocks do all right on my Sporty but I had a small inline fuel filter that didn't work too well.
Got up to 65 on the Hi-way and she felt like she was starvin' 4 go-juice put in a larger
filter (about 2 inches diameter) and she ran fine. Thing is I replaced valve with what I thought was
same as 1st as the tube height is the same.
It was a weird thing, around 96 to a 100 miles on main tank, starts crapping out as it was there
was a gas station, she took a gallon so it meant I was getting 48 to 50 a gallon, turns out the petcock
was fouled up with all sorts o' **** at the base next to the tube, so reserve did not work.
I somehow got the idea that since the P'nut tanks were 2 and a 1/4 gallons, the reserve was good for
12 to 12 and a half miles, so at 48 mpg without reserve came to 134 miles. So I get up to 34 miles
figuring I'd be changing over to reserve pretty quickly, I was right, she started to **** out and I switched
to reserve with NO continuation of engine running. The tank was empty like WTF?" I still have the
old valve I will probably put old valve back in and get some reserve or carry a 1 gal Jerry jug on back porch
back rest, yeah than I have another 48 miles.