Recently got an 86' Spree to fix/get running again. It had been sitting for at least 1 year, so everything was dirty and clogged up. Here's what I've done so far. I seem to be having a fuel issue (vacuum).
-Drained old gas/oil
-Clean out gas tank/oil tank
-New spark plug (has good spark)
-New fuel/vacuum lines
-Added an in-line fuel filter
-New air filter
-New/Charged battery
-Carb cleaned... multiple times (float is good)
-Everything electrical works so far (bystarter has been checked with 12v)
-Compression seems good
First question I have is the intake/vacuum line. I soaked the gas valve in gas for a day or so, then checked it and seemed good (apply very little suction to vacuum line and gas flows easily out of gas line). But it seems like the engine/intake isn't pulling enough vacuum to cause the gas valve to open (hooked a vacuum gauge to the vacuum inlet on intake while running and nothing).
My next guess is the reeds, although I did pull the intake off and looked/poked at the reeds and they looked and moved fine. I did not pull the completely off, but I'm probably going to soon. So here's the question. What creates the vacuum (suction) that in turn causes the gas valve to open for gas to flow? I would think the piston moving up and down would pull air/gas mixture, that would also pull gas valve open. Lastly, the only way I could get it to even start was to put gas straight in the cylinder, and hold throttle wide open while cranking 10-15 times. Only would even sound like starting while wide open, which doesn't make much sense. There's no fuel in the carb, so only more air is being pulled into cylinder. Thanks for any help, lots of great people and info here.
Spree starting issues... fuel problem?
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chevyguyjay
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79vwrabbit
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You are correct that the piston action creates pressure waves that draw in fuel/air from the carburetor. On the Spree, this pressure also acts through the little petcock line and operates the vacuum petcock. It's really a simple system used on many, many machines. It sounds to me like your engine is ready to start, but isn't receiving fuel.
The line that runs from the petcock to the intake manifold may have blockage, or there may be something in the brass pipe in the alumimum manifold that is causing trouble. Try taking the line off the manifold and sticking a small wire into the brass pipe to make sure it's clear.
To test the engine by itself, you can plug off the vacuum line (so it's not sucking air and causing a lean mixture) and then feeding the carburetor from an external fuel tank. What I do is pop a large syringe into the fuel line and tape it up so it doesn't fall over and feed the carburetor by pouring fuel into the syringe.
It's probably just something simple like a plugged line though.
The line that runs from the petcock to the intake manifold may have blockage, or there may be something in the brass pipe in the alumimum manifold that is causing trouble. Try taking the line off the manifold and sticking a small wire into the brass pipe to make sure it's clear.
To test the engine by itself, you can plug off the vacuum line (so it's not sucking air and causing a lean mixture) and then feeding the carburetor from an external fuel tank. What I do is pop a large syringe into the fuel line and tape it up so it doesn't fall over and feed the carburetor by pouring fuel into the syringe.
It's probably just something simple like a plugged line though.
Not exactly progress, but more problems. I think I fixed the vacuum problem (fuel fills up bowl), but I still can't get it to start. Here's the new problem though. Right under the final drive cover (at point where crank case meets final drive cover) I'm leaking (spewing when attempting to start) a mixture of gas/oil. For some reason, the engine/piston is receiving the mixture of fuel/air from the carburetor. Somehow it's leaking out and making it's way back to the back of the case. Any thoughts on this? My theory is the oil seal on the side of the crank, as that is the only piece keeping fluids in the crank and cylinder area and it separates the crank from crankcase. Maybe the crank gasket? Also, besides the breather at the very rear that goes into the rear fender, is there another breather anywhere else? It has 47xx miles and 110psi, and little carbon on the piston (looked with small mirror). Thanks for the help, this thing is kicking my butt.
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79vwrabbit
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This is not good-sounds more complicated than a plugged line. From your description, it sounds like the left main seal is leaking. You're right-there are oil seals on each side of the crankshaft that seal in the mixture. They must hold pressure for the engine to run. If one is leaking, the engine won't run very well or at all depending on how bad the leak is. Fuel is definitely not supposed to be getting down to the transmission/belt drive. I'm not at the shop right now with my Spree to be able to give you really accurate advice, but here's what I would do:
The left main seal has to be changed no matter what. The correct procedure is to disassemble the engine, split the cases, take out the crankshaft and knock out the bearings to get to the seals, where they can be easily changed. It's not really that difficult on the Spree, but probably more work than you're looking to get into right now.
So what I would do would be to take off the belt cover and remove the front pulley on the crankshaft (both halves). Then I would try to remove the seal from the outside by drilling good metal screws into the seal and trying to pull it out. Try to stay away from the seal housing with the extraction equipment. This technique usually works with patience, but you'll end up destroying the seal. Small screwdrivers sometimes help work it out too. Once you get it out all you have to do is make sure all remnants of it are gone, and then you're safe to drive in the new seal with a socket. Don't forget to put some grease on the seal lips to help it seal to the crankshaft.
The seals usually last a long time. But if the machine sat for a long time, this failure isn't too surprising. It also happens with a lot of miles and wear. It makes you wonder about the condition of the other seal though, but hey, "if it ain't broke, don't fix it."
The left main seal has to be changed no matter what. The correct procedure is to disassemble the engine, split the cases, take out the crankshaft and knock out the bearings to get to the seals, where they can be easily changed. It's not really that difficult on the Spree, but probably more work than you're looking to get into right now.
So what I would do would be to take off the belt cover and remove the front pulley on the crankshaft (both halves). Then I would try to remove the seal from the outside by drilling good metal screws into the seal and trying to pull it out. Try to stay away from the seal housing with the extraction equipment. This technique usually works with patience, but you'll end up destroying the seal. Small screwdrivers sometimes help work it out too. Once you get it out all you have to do is make sure all remnants of it are gone, and then you're safe to drive in the new seal with a socket. Don't forget to put some grease on the seal lips to help it seal to the crankshaft.
The seals usually last a long time. But if the machine sat for a long time, this failure isn't too surprising. It also happens with a lot of miles and wear. It makes you wonder about the condition of the other seal though, but hey, "if it ain't broke, don't fix it."