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Post by rockynv on Dec 21, 2015 5:28:27 GMT -5
Remember that foam air filters are only semi-permanent and still require replacement after one or two cleanings as the foam starts to break down which happens more rapidly since ethanol came into use. A one cylinder engine develops a pulse that flows back through the intake which is what allows the vacuum fuel pump to operate and mists a little fuel vapor back at the filter which when laden with ethanol rots away at it until it eventually can tear and be sucked into the cylinder along with all the dirt it contains.
Myself in the past 50,000 miles of riding scooters instead of motorcycles I have not had a vacuum shut off fail of its own but have had bad vacuum lines and intake parts fail preventing enough vacuum to open them (so far not on the Aprilia though).
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Post by geh3333 on Dec 28, 2015 18:08:42 GMT -5
vacuum shutoff valves for 50cc engines shouldn't pose much of a problem. mine never gave any problems. the issue arises with 250cc engines, and probably 150cc too. i simply had enough of the constant WOT then release. twist fully open, then having to close the throttle. finally tossed the vacuum valve and at first got an electrically operated pump. i do not recommend a electrically operated pump. i went to NAPA and got a manual valve for a briggs and stratton engine. you need to be aware of shutting off the fuel EVERY TIME you get off your ride. carb floats usually work pretty good at shutting off fuel flow, but sometimes they stick open. combine that with a particular position of the combustion cycle and you can wind up with an engine full of gas. i finally eliminated all of my vacuum lines except for the air cutoff valve. i would have eliminated that one too but i didn't like my scoot back firing on closed throttle. 6 inches from fuel tank outlet to carb inlet is sufficient for constant fuel flow for a 250, even at WOT. the reason i don't recommend an electrical pump is because of the pressure of the fuel. i found this out the hard way. i didn't get one of my band clamps tight enough and the fuel line to the carb blew off at speed. my chines scoot just up and died, and there i am thinking "what now?" so i park the ride, raised the seat, and started looking around, then finally noticed the stream of gas shooting out of the fuel line. that could have been a very bad situation. OTOH, some type of pump will be required for a tank below the carb inlet. just be careful with an electric pump. Many have issues with the cheap junk vacuum petcocks , that's why many switch to a Manuel shutoff instead , no vacuum , no worries. U must buy the right electric fuel pump or that will happen . there are many out there with different fuel pressure ratings. |
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Post by geh3333 on Dec 28, 2015 18:19:28 GMT -5
Remember that foam air filters are only semi-permanent and still require replacement after one or two cleanings as the foam starts to break down which happens more rapidly since ethanol came into use. A one cylinder engine develops a pulse that flows back through the intake which is what allows the vacuum fuel pump to operate and mists a little fuel vapor back at the filter which when laden with ethanol rots away at it until it eventually can tear and be sucked into the cylinder along with all the dirt it contains. Myself in the past 50,000 miles of riding scooters instead of motorcycles I have not had a vacuum shut off fail of its own but have had bad vacuum lines and intake parts fail preventing enough vacuum to open them (so far not on the Aprilia though). I've had the same foam uni filter for 20,000 + miles and its still going strong . it wouldnt be worth the $30 for a foam unifilter if you had to replace it after a couple cleanings. |
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Post by dollartwentyfive on Dec 28, 2015 18:30:51 GMT -5
Many have issues with the cheap junk vacuum petcocks , that's why many switch to a Manuel shutoff instead , no vacuum , no worries. U must buy the right electric fuel pump or that will happen . there are many out there with different fuel pressure ratings. my vacuum valve wasn't cheap or junk. it just didn't work right above a certain speed, it didn't maintain the needed vacuum. yes, i'm well aware there are different pumps with different pressure ratings. unfortunately no one has an expert opinion on the matter other than "go buy one, see if it works". it's all good, a manual valve set me up. the only problem with a manual valve is remembering to shut it off. |
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Post by rcq92130 on Dec 28, 2015 19:22:01 GMT -5
vacuum shutoff valves for 50cc engines shouldn't pose much of a problem. mine never gave any problems. the issue arises with 250cc engines, and probably 150cc too. i simply had enough of the constant WOT then release. twist fully open, then having to close the throttle. finally tossed the vacuum valve and at first got an electrically operated pump. i do not recommend a electrically operated pump. i went to NAPA and got a manual valve for a briggs and stratton engine. you need to be aware of shutting off the fuel EVERY TIME you get off your ride. carb floats usually work pretty good at shutting off fuel flow, but sometimes they stick open. combine that with a particular position of the combustion cycle and you can wind up with an engine full of gas. i finally eliminated all of my vacuum lines except for the air cutoff valve. i would have eliminated that one too but i didn't like my scoot back firing on closed throttle. 6 inches from fuel tank outlet to carb inlet is sufficient for constant fuel flow for a 250, even at WOT. the reason i don't recommend an electrical pump is because of the pressure of the fuel. i found this out the hard way. i didn't get one of my band clamps tight enough and the fuel line to the carb blew off at speed. my chines scoot just up and died, and there i am thinking "what now?" so i park the ride, raised the seat, and started looking around, then finally noticed the stream of gas shooting out of the fuel line. that could have been a very bad situation. OTOH, some type of pump will be required for a tank below the carb inlet. just be careful with an electric pump. Many have issues with the cheap junk vacuum petcocks , that's why many switch to a Manuel shutoff instead , no vacuum , no worries. U must buy the right electric fuel pump or that will happen . there are many out there with different fuel pressure ratings. Hold on now, Hoss. As you well know, I've been running an electric pump since early last year and find it the single best improvement ever that can be made. Consider: when was the last time you saw a car manufactured with anything other than an electric pump?? Those ChinaPump vacuum things are like 18th century! Of COURSE you have to get one that is suited for a carbureted engine (duh!), not injected. And I strongly suggest getting a little pressure regulator set to about 2psi, since the ChinNeedleValve in our carburetor is butt-hurt at anything over about 4psi, and even pumps designed specifically for carb. engines are not all that great at keeping pressure down that low. But boy oh boy are the advantages great. |
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Post by dollartwentyfive on Dec 28, 2015 19:48:50 GMT -5
Hold on now, Hoss. As you well know, I've been running an electric pump since early last year and find it the single best improvement ever that can be made. how would i know anything about what you were running last year, and furthermore why would i care? mine wasn't a pump, it was a valve, and as to the other, when was the last time you seen an automobile with the gas tank outlet at least a foot above the carb inlet? an american made valve will suffer from the same shortages as a chinese valve, namely a lack of vacuum. if the vacuum is sufficient then either will work. lumping all chinese made stuff into the category of junk just simply isn't true, nor is it fair. my tank was above the engine, all that was needed was a fuel line to connect the 2, and of course a valve to shut off the fuel. the valve i bought works great. 6 inches vertical height between tank outlet and carb inlet was sufficient for my 244 at WOT. i can't remember if i used (1/4) or (3/8) hose. |
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Post by rcq92130 on Dec 28, 2015 19:51:34 GMT -5
"how would i know anything about what you were running last year, and furthermore why would i care?"
I respectfully suggest that when a response is directed to GEH it does not mean it is directed to, nor refer to, you. As for your caring, I have no response.
"mine wasn't a pump, it was a valve"
Again, when a response is directed toward another person it might not be directed to you. But, I took you are your word when you said (and i quote): "finally tossed the vacuum valve and at first got an electrically operated pump. i do not recommend a electrically operated pump."
Oh, and I used 1/4" hose. Black. And a filter before the ELECTRIC pump. Clear.
"an american made valve will suffer from the same shortages as a chinese valve, namely a lack of vacuum."
Well, that is true but I disagree if you have an ELECTRIC pump, which does not rely on vacuum at all.
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Post by tvnacman on Dec 28, 2015 19:57:39 GMT -5
if your going through so many fuel shut off valves then there is something wrong. Vac valves have a screen on the inlet side.
John
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Post by dollartwentyfive on Dec 28, 2015 20:09:15 GMT -5
I respectfully suggest that when a response is directed to GEH it does not mean it is directed to, nor refer to, you. As for your caring, I have no response. i understand. i missed the last part of the post. yes, that's what i said. i had this pump a grand total of 2 days before i got rid of it. the situation is a little more complicated with a below engine tank, i don't see how you can get around an electric pump, and i advise caution in using them. a perfect solution would rely on oil pressure, either pump or valve. i'm not aware of any such device. |
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Post by rcq92130 on Dec 28, 2015 20:43:39 GMT -5
I've had the same foam uni filter for 20,000 + miles and its still going strong . it wouldnt be worth the $30 for a foam unifilter if you had to replace it after a couple cleanings. Yeah, but did your foam filter have bushings? |
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Post by geh3333 on Dec 28, 2015 20:51:16 GMT -5
Many have issues with the cheap junk vacuum petcocks , that's why many switch to a Manuel shutoff instead , no vacuum , no worries. U must buy the right electric fuel pump or that will happen . there are many out there with different fuel pressure ratings. my vacuum valve wasn't cheap or junk. it just didn't work right above a certain speed, it didn't maintain the needed vacuum. yes, i'm well aware there are different pumps with different pressure ratings. unfortunately no one has an expert opinion on the matter other than "go buy one, see if it works". it's all good, a manual valve set me up. the only problem with a manual valve is remembering to shut it off. Lol, that's some funny stuff . sorry buddy bit that's the definition of "cheap or junk " . " it wasn't junk , it just didn't work right above certain speeds"!! That's like saying " my scoot is not junk , it just only runs once a year. " or my CD player isn't junk it just plays certain CDs . or my scoot battery isnt junk it just won't work when its hooked up . Like rcq said , those vacuum valves are nothing but a piece of the 1800's thrown into 20th century tech . many times they turn out to be a problem . using a simple design that never gets old and always comes through " the manual shutoff valve" is the way to go . the manual valve eliminates any need for any vacuum lines . u can plug all vacuum lines or just cap off all vacuum ports and not worry about vacuum issues anymore !! |
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Post by dollartwentyfive on Dec 28, 2015 21:41:28 GMT -5
my vacuum valve wasn't cheap or junk. it just didn't work right above a certain speed, it didn't maintain the needed vacuum. yes, i'm well aware there are different pumps with different pressure ratings. unfortunately no one has an expert opinion on the matter other than "go buy one, see if it works". it's all good, a manual valve set me up. the only problem with a manual valve is remembering to shut it off. Lol, that's some funny stuff . sorry buddy bit that's the definition of "cheap or junk " . " it wasn't junk , it just didn't work right above certain speeds"!! That's like saying " my scoot is not junk , it just only runs once a year. " or my CD player isn't junk it just plays certain CDs . or my scoot battery isnt junk it just won't work when its hooked up . Like rcq said , those vacuum valves are nothing but a piece of the 1800's thrown into 20th century tech . many times they turn out to be a problem . using a simple design that never gets old and always comes through " the manual shutoff valve" is the way to go . the manual valve eliminates any need for any vacuum lines . u can plug all vacuum lines or just cap off all vacuum ports and not worry about vacuum issues anymore !! i'm glad you find it amusing. the vacuum valve on my 50cc never gave me a bit of trouble. have any idea how much of that "eighteenth century technology" is used on a modern car engine? unless it has changed, the power for your "power brakes" is EXACTLY the same technology that these fuel valves use. any comment on that? |
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Post by rcq92130 on Dec 28, 2015 22:06:14 GMT -5
"have any idea how much of that "eighteenth century technology" is used on a modern car engine?
unless it has changed, the power for your "power brakes" is EXACTLY the same technology that these fuel valves use.
any comment on that?"
Vacuum cleaners too
And vacuum suction devices used in the surgery room
And in closing food storage bags
And in abortions (yuk)
But, silly me, I thought all along we were talking about FUEL DELIVERY !!!!!!!!!!!!!!!!!!!!!!!!!
Has anyone else noticed this thread has become the poster child of moving goalposts?
LOL LOL LOL
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Post by geh3333 on Dec 28, 2015 22:13:28 GMT -5
There is a lot more to power brakes then there is in one of the vacuum valves. The problem is that the chinese vacuum operated fuel valves are known to go bad pretty often . and the 1800 remark was not meant to be taken seriously .
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Post by dollartwentyfive on Dec 28, 2015 22:47:03 GMT -5
There is a lot more to power brakes then there is in one of the vacuum valves. correct. the vacuum booster on power brakes is just one item that make up the brake system, just like the vacuum valve is one item in the fuel system. the vacuum booster is essentially a big vacuum valve. they don't go bad as often as they are being used outside their design specs. the majority of 50cc owners seldom have problems with them. noted for future reference. so, just when are we to take you seriously? |
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