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Post by brndnpnt on Dec 29, 2010 13:54:59 GMT -6
Anyone taken apart a fuel pump? Whats in these things that make them fail so often?
Any links to electric fuel pump setups
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Post by Alleyoop on Dec 29, 2010 14:13:32 GMT -6
Some fuel pumps are very cheaply made and most you cannot re-build once they go you have to get a new one. But if you do get a new one get a Mikuni they are a quality fuel pump and you can re-build them. They basically have a Diaphgram in them and the Vacuum from your engine pumps the Diaphgram up and down to pump the fuel up to your Fuel Filter to your carb.
How do you know the problem is your Fuel Pump, did you test it? Did you check your Vacuum hose going to the Fuel Pump as well as the Vacuum hose coming from your intake. If you have a leaky Vacuum hose it will not pump strong enough to get the fuel to your carb or not fast enough to fill your carb bowl.
Alleyoop
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Post by Cruiser on Dec 29, 2010 19:48:01 GMT -6
To tell the truth, I didn't realize that the OEM vacuum pumps failed that often. I know that the Mikuni is a better performing pump and can be rebuilt for only a few bucks. I went with an electric on my YY250T to ensure reliable high speed performance and also to eliminate the need to prime the carburetor manually if you ever need to drain it for maintenance or tuning. The vacuum lines for the 244cc engine are a little long which also takes away from the fuel pump performance. Here's a couple of pictures of my electric pump setup:   One of the things to remember is to mount the pump lower than the tank and angle the output up at about 45 degrees. |
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Post by brndnpnt on Dec 30, 2010 10:58:55 GMT -6
Some fuel pumps are very cheaply made and most you cannot re-build once they go you have to get a new one. But if you do get a new one get a Mikuni they are a quality fuel pump and you can re-build them. They basically have a Diaphgram in them and the Vacuum from your engine pumps the Diaphgram up and down to pump the fuel up to your Fuel Filter to your carb. How do you know the problem is your Fuel Pump, did you test it? Did you check your Vacuum hose going to the Fuel Pump as well as the Vacuum hose coming from your intake. If you have a leaky Vacuum hose it will not pump strong enough to get the fuel to your carb or not fast enough to fill your carb bowl. Alleyoop Everything looked good hoses exct.. Just happends that one day I got off the interstate and the bike just suddenly started acting like it was not getting any gas... |
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Post by brndnpnt on Dec 30, 2010 10:59:27 GMT -6
To tell the truth, I didn't realize that the OEM vacuum pumps failed that often. I know that the Mikuni is a better performing pump and can be rebuilt for only a few bucks. I went with an electric on my YY250T to ensure reliable high speed performance and also to eliminate the need to prime the carburetor manually if you ever need to drain it for maintenance or tuning. The vacuum lines for the 244cc engine are a little long which also takes away from the fuel pump performance. Here's a couple of pictures of my electric pump setup: One of the things to remember is to mount the pump lower than the tank and angle the output up at about 45 degrees. Where did you get that pump and how much did you pay for it? |
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Post by Alleyoop on Dec 30, 2010 13:20:58 GMT -6
What happened to you does not mean the Fuel Pump is bad. To test it unplug the Fuel hose from the Carb and get a container to catch the fuel. Then Crank the engine over and if Fuel Streams out it is good. If it Trickles out then check your Fuel Filter(it could be Clogged), to test that Take the Fuel Filter out and Crank it again if Fuel Streams out without the Fuel Filter then get a new Fuel Filter. Also check if your Fuel Tank is venting, Crack the cap open a little and see if it still does it. If its not venting it will stop fuel from flowing to your Fuel Pump. Could also be some crud got into your bowl and plugged up your jets.
Alleyoop
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Post by Cruiser on Dec 30, 2010 14:29:12 GMT -6
My pump was a one time buy for $26. Here is a link to the equivalent pump: www.summitracing.com/parts/MRG-42SFuel pump problems usually show at high speeds in the form of fuel starvation. If a fuel pump is bad enough to mess up the idle, you won't be able to drive down the street because more fuel is needed to drive. The problem you described sounds like a sticking needle valve. This usually happens after driving for a period of time at full throttle or nearly full throttle. The needle valve remains in the open throttle position when you slow to a stop and this will usually stall out the scoot. Sometimes the needle valve will slide back down by itself from engine vibrations and sometimes you have to tap on the circular dome cover on top of the carburetor to get it to slide down. |
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Post by brndnpnt on Dec 30, 2010 22:00:40 GMT -6
What happened to you does not mean the Fuel Pump is bad. To test it unplug the Fuel hose from the Carb and get a container to catch the fuel. Then Crank the engine over and if Fuel Streams out it is good. If it Trickles out then check your Fuel Filter(it could be Clogged), to test that Take the Fuel Filter out and Crank it again if Fuel Streams out without the Fuel Filter then get a new Fuel Filter. Also check if your Fuel Tank is venting, Crack the cap open a little and see if it still does it. If its not venting it will stop fuel from flowing to your Fuel Pump. Could also be some crud got into your bowl and plugged up your jets. Alleyoop I came to the fuel pump idea becasue. I took the carb out and blew it all out good with carb cleaner. Replaced the fuel filter though it did have crud in it. I looked at the hoses and they seemed ok. and I also did let the fuel run into a butter tub with the motor running and it trickels alot more than streams.... I have a fuel pump comeing in this monday ill get back to you after I upgrade the fuel lines and install the pump.... Hope it works. The carb was my first idea so I did that first.. There was some moisture in the carb that looked like water so I also checked the gas by draining the fuel into something so i could look for water....  be back soon |
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Post by brndnpnt on Jan 3, 2011 20:55:53 GMT -6
What happened to you does not mean the Fuel Pump is bad. To test it unplug the Fuel hose from the Carb and get a container to catch the fuel. Then Crank the engine over and if Fuel Streams out it is good. If it Trickles out then check your Fuel Filter(it could be Clogged), to test that Take the Fuel Filter out and Crank it again if Fuel Streams out without the Fuel Filter then get a new Fuel Filter. Also check if your Fuel Tank is venting, Crack the cap open a little and see if it still does it. If its not venting it will stop fuel from flowing to your Fuel Pump. Could also be some crud got into your bowl and plugged up your jets. Alleyoop I put the new fuel pump on and started it up but did not install it. It cranked right up  so I am glad thats done. I opened up the old fuel pump and it did not look like anything goes inside but I do think the fuel was leaking out or had a vacume leek somewhere on the seals because fuel was leeking out of the side when i took it off... |
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..BAD TO THE BONE..
be back soon
so I am glad thats done.