@@ApacheRanch True. Its my new favorite word even, except I made it two words now and tell everyone. I want to get one I can carry around and show everyone.
Thank you for the instruction. I just installed a brand new vacuum petcock and tried to test it by sucking on the air line… no fuel flowing. Any suggestions on what to check?
Good video. I would only like to add though. That device also pump gas out, but it uses the pressure inside the intake manifold. As the intake valve open while the piston going down, a vacuum occurs inside the intake manifold where the vaccum line of the pump is linked, hence the flow of gas is open. When the intake valve shuts down, an instantaneos close of space happens in the intake manifold and that pressure needs to go somewhere and some of that goes to the vaccum pump again, forcibly closing the diaphram. With the aspect of forcing the diaphram to close, it pushes any remaining fuel in the fuel bowl of the vaccum pump, gushing out fuel to the carburetor during the combustion stroke. Thats why most vaccum pump are just for small displacement engines that doesnt revs too much(go way beyond 9k rpm) because the diaphram could only handle much torture before giving. And also the pressure that is being produced by the pump is directly proportional to the engine revolution.
i bypaased it just to get home. but when rev it dies or if i don't rev it dies. with the air filter on the bike or off the bike still same brob. i accidentally put too much oil in the scooter while premixing i been trying to put fresh gas to burn out the oil but it won't stay running to do so unless i putt around going 5 miles hr. please help . i have a piaggio 50cc typhoon. del orto phva carb . leo vince evo 2 pipe . thx in advance
For an older autocock with a stuck diaphragm due to varnished gas, you can pop the diaphragm loose with a quick burst of compressed air. I got the old autocock on my 1981 Honda Express SR50 to work again using this method. I followed this up with a soak in pine sol to completely remove all the old varnished gas. Replacing the SR50 autocock is nearly impossible as it uses 14mm threads.
I have a vacuum valve on my scooter just like the smaller first one you showed. When I put the hose on the vacuum (lower opening on the tap) and imitate the operation, I pull in and blow air, fuel starts on the upper tap, but it also starts on the vacuum on the lower opening, I drank a little petrol 😂 does that mean that the membrane inside is punctured?
Brett Cox you really can’t. These are pressed together and if you pry it open you end up damaging it. And there’s nothing repairable inside anyhow. $10 on eBay!
Not really. Usually just replace it. Amazon has them. Link in the description. Ensure that you order the proper year for your Spree as the bolts are different sizes 84-85 vs 86-87.
Here's where to find replacement Honda Spree petcocks - amzn.to/31vQxqG
Your videos are great. I learned more about petcocks today.
Yes, you did. And now you will never be the same! Lol
@@ApacheRanch True. Its my new favorite word even, except I made it two words now and tell everyone. I want to get one I can carry around and show everyone.
Fantastic explanation - I appreciate it so much thank you!
thank you very for well explained 🙏all the best
Thank you for the instruction. I just installed a brand new vacuum petcock and tried to test it by sucking on the air line… no fuel flowing. Any suggestions on what to check?
Alright. Cool. But where on the carburetor does the vacuum line hook up to???
Good video. I would only like to add though. That device also pump gas out, but it uses the pressure inside the intake manifold. As the intake valve open while the piston going down, a vacuum occurs inside the intake manifold where the vaccum line of the pump is linked, hence the flow of gas is open. When the intake valve shuts down, an instantaneos close of space happens in the intake manifold and that pressure needs to go somewhere and some of that goes to the vaccum pump again, forcibly closing the diaphram. With the aspect of forcing the diaphram to close, it pushes any remaining fuel in the fuel bowl of the vaccum pump, gushing out fuel to the carburetor during the combustion stroke. Thats why most vaccum pump are just for small displacement engines that doesnt revs too much(go way beyond 9k rpm) because the diaphram could only handle much torture before giving. And also the pressure that is being produced by the pump is directly proportional to the engine revolution.
Very well described!
i bypaased it just to get home. but when rev it dies or if i don't rev it dies. with the air filter on the bike or off the bike still same brob. i accidentally put too much oil in the scooter while premixing i been trying to put fresh gas to burn out the oil but it won't stay running to do so unless i putt around going 5 miles hr. please help . i have a piaggio 50cc typhoon. del orto phva carb . leo vince evo 2 pipe . thx in advance
Perhaps float needle is not moving in/out properly?
For an older autocock with a stuck diaphragm due to varnished gas, you can pop the diaphragm loose with a quick burst of compressed air. I got the old autocock on my 1981 Honda Express SR50 to work again using this method. I followed this up with a soak in pine sol to completely remove all the old varnished gas. Replacing the SR50 autocock is nearly impossible as it uses 14mm threads.
Thanks for your comment! Very good information!!
Any substitute for pine sol?
@@mattcat1148 I'm sure there is but Pine Sol is an old tried and true method for removing varnished gas. I soaked the carb as well.
@@jt8251 thank you
I have a vacuum valve on my scooter just like the smaller first one you showed. When I put the hose on the vacuum (lower opening on the tap) and imitate the operation, I pull in and blow air, fuel starts on the upper tap, but it also starts on the vacuum on the lower opening, I drank a little petrol 😂 does that mean that the membrane inside is punctured?
Yes, I would believe that fuel is leaking past the membrane
yo man do you know what a 2010 kymco quannon is?
Thanks a lot. If I want to open it up though, how can it be done?
Brett Cox you really can’t. These are pressed together and if you pry it open you end up damaging it. And there’s nothing repairable inside anyhow. $10 on eBay!
@@ApacheRanch Gotcha. I'm about to replace mine but would love to look inside to see if it's gummed up like I think it is or not.
@@BCVideos01 I would go for it. Probably a cutting wheel on a dremel tool would work? Put it in a vice to hold it steady. Then cut around the circle?
Thank you my friend
Glad it helped!
Is it reparable Sir?
Not really. Usually just replace it. Amazon has them. Link in the description. Ensure that you order the proper year for your Spree as the bolts are different sizes 84-85 vs 86-87.
I was riding one day and shut off. The next morning my gas tank was empty. I removed the gas line from the petcock to the carb no gas came out.
nice
my moped has a vacuum petcock, im thinking of replacing it with a normal manual tap, maybe a reserve mode one. screw these vacuum tings
Their junk thats why they fail. Better to use a fuel shut off valve instead.
*they are