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18HP Briggs v-twin Vanguard engine guru needed
#4
tom3
tom3
#7
A
(Account Closed)
A
(Account Closed)
With the lower compression now on the one side and burning of oil, it sounds as if the rings for that side are worn.
To check those W/O major disassembly, you need to do a "leak down test". On that cylinder, get it to TDC on the compression stroke. Lock up the engine so it does NOT rotate.
Insert your tool, pressurize it to 100PSI and listen/feel for leaks. You'll likely feel much of the air come out of the oil filler neck (air pushed past the compression rings into the crankcase). You shouldn't be dropping more than roughly 15%.
(if air comes out the carb-bad intake valve, exhaust-exhaust valve- yours will very likely come out the oil filler opening)
Compared to the other cylinder, it sounds like your closer to loosing 50%, not good
….
I suspect the fuel that seeped into the oil allowed for some extra wear on that one cylinder for some reason.
To check those W/O major disassembly, you need to do a "leak down test". On that cylinder, get it to TDC on the compression stroke. Lock up the engine so it does NOT rotate.
Insert your tool, pressurize it to 100PSI and listen/feel for leaks. You'll likely feel much of the air come out of the oil filler neck (air pushed past the compression rings into the crankcase). You shouldn't be dropping more than roughly 15%.
(if air comes out the carb-bad intake valve, exhaust-exhaust valve- yours will very likely come out the oil filler opening)
Compared to the other cylinder, it sounds like your closer to loosing 50%, not good
….I suspect the fuel that seeped into the oil allowed for some extra wear on that one cylinder for some reason.
#8
Fish
Fish
#9
S
Sean2202
S
Sean2202
Thank you all for your replies. I rechecked the valve clearance again according to the FSM. My FSM states 1/4 past TDC on compression stroke. My clearances where all on target set at .005. (FSM states .004-.006 intake and exhaust cold). I have found some discrepancies with my FSM as I believe there has been updates so are the valves still checked this way?
Thanks for the tip on the fuel solenoid. In my fleet of B&S engines (10 or So) What is the best way to make sure the float valve is not stuck? I have been turning the gas off if the machine is not used often. Should we stick to 50 hr oil changes to keep an eye on things better? On my new engine it recommends oil change at 100 now. How many hours or time would it take for a leaking carb float to add enough gas contamination to oil to damage an engine? Does the fuel always flow into the same cylinder, the side with the starter. The reason why I am asking is I have another engine of the same vintage that the compression on the RH (starter side) is about 15 psi off of the right side. This machine only gets used about 100 hrs a year. I did not find oil in the air cleaner, overfilled, or discolored oil when I drained it.
Also I have read to wash the prefilter, then lightly oil it and squeeze out the excess. The new book I have does not say anything about this. What is the preferred method?
I have purchased a new engine for this piece of equipment and will play with this old engine when I have time. I will definitely try that leak down tester method. Thanks for sharing.
Here are some original pictures that I took before and after. The first is the RH side with the starter that shows the oil around the head gasket area and piston. The head gasket did have a leaking spot here. Next pictures are of after I cleaned the whole engine. Not sure if you can tell from the second picture but the piston seemed like it was closer to the cylinder wall on the side with lower compression than the side that had normal compression. Although this engine ran could it be as simple as replacing the rings and a simple hone? Unfortunately I did not take any photos of the underside of the valves and heads. They had carbon deposits but did not seem extremely excessive.
Sean
Thanks for the tip on the fuel solenoid. In my fleet of B&S engines (10 or So) What is the best way to make sure the float valve is not stuck? I have been turning the gas off if the machine is not used often. Should we stick to 50 hr oil changes to keep an eye on things better? On my new engine it recommends oil change at 100 now. How many hours or time would it take for a leaking carb float to add enough gas contamination to oil to damage an engine? Does the fuel always flow into the same cylinder, the side with the starter. The reason why I am asking is I have another engine of the same vintage that the compression on the RH (starter side) is about 15 psi off of the right side. This machine only gets used about 100 hrs a year. I did not find oil in the air cleaner, overfilled, or discolored oil when I drained it.
Also I have read to wash the prefilter, then lightly oil it and squeeze out the excess. The new book I have does not say anything about this. What is the preferred method?
I have purchased a new engine for this piece of equipment and will play with this old engine when I have time. I will definitely try that leak down tester method. Thanks for sharing.
Here are some original pictures that I took before and after. The first is the RH side with the starter that shows the oil around the head gasket area and piston. The head gasket did have a leaking spot here. Next pictures are of after I cleaned the whole engine. Not sure if you can tell from the second picture but the piston seemed like it was closer to the cylinder wall on the side with lower compression than the side that had normal compression. Although this engine ran could it be as simple as replacing the rings and a simple hone? Unfortunately I did not take any photos of the underside of the valves and heads. They had carbon deposits but did not seem extremely excessive.
Sean
#10
I
ILENGINE
15 psi off could be a big thing if you have 100 psi on the good cylinder or nothing to worry about if the good cylinder is 160 psi. The latest information is to not oil the precleaner on a paper cartridge type filter. the problem is most people over oil them. Lightly oil according to Briggs is 1 tsp for the whole surround filter. So the current recommendation is to oil a foam only type filter(push mower filters) and not oil the foam over paper filter.
50 hour oil changes is fine, The gas in the oil by itself won't damage the engine, The problem is running it with the gas in the oil which will damage the engine. A leaking float valve on a fuel pump engine will quickly overwhelm the engine in most cases. A leaking float valve on a gravity feed engine if leaking bad will cause the engine to run rich and normally blow black smoke as it floods the engine, or if let to set will fill the crankcase in just a few minutes in some cases.
I
ILENGINE
Thank you all for your replies. I rechecked the valve clearance again according to the FSM. My FSM states 1/4 past TDC on compression stroke. My clearances where all on target set at .005. (FSM states .004-.006 intake and exhaust cold). I have found some discrepancies with my FSM as I believe there has been updates so are the valves still checked this way?
Thanks for the tip on the fuel solenoid. In my fleet of B&S engines (10 or So) What is the best way to make sure the float valve is not stuck? I have been turning the gas off if the machine is not used often. Should we stick to 50 hr oil changes to keep an eye on things better? On my new engine it recommends oil change at 100 now. How many hours or time would it take for a leaking carb float to add enough gas contamination to oil to damage an engine? Does the fuel always flow into the same cylinder, the side with the starter. The reason why I am asking is I have another engine of the same vintage that the compression on the RH (starter side) is about 15 psi off of the right side. This machine only gets used about 100 hrs a year. I did not find oil in the air cleaner, overfilled, or discolored oil when I drained it.
Also I have read to wash the prefilter, then lightly oil it and squeeze out the excess. The new book I have does not say anything about this. What is the preferred method?
I have purchased a new engine for this piece of equipment and will play with this old engine when I have time. I will definitely try that leak down tester method. Thanks for sharing.
Here are some original pictures that I took before and after. The first is the RH side with the starter that shows the oil around the head gasket area and piston. The head gasket did have a leaking spot here. Next pictures are of after I cleaned the whole engine. Not sure if you can tell from the second picture but the piston seemed like it was closer to the cylinder wall on the side with lower compression than the side that had normal compression. Although this engine ran could it be as simple as replacing the rings and a simple hone? Unfortunately I did not take any photos of the underside of the valves and heads. They had carbon deposits but did not seem extremely excessive.
Sean
15 psi off could be a big thing if you have 100 psi on the good cylinder or nothing to worry about if the good cylinder is 160 psi. The latest information is to not oil the precleaner on a paper cartridge type filter. the problem is most people over oil them. Lightly oil according to Briggs is 1 tsp for the whole surround filter. So the current recommendation is to oil a foam only type filter(push mower filters) and not oil the foam over paper filter.
50 hour oil changes is fine, The gas in the oil by itself won't damage the engine, The problem is running it with the gas in the oil which will damage the engine. A leaking float valve on a fuel pump engine will quickly overwhelm the engine in most cases. A leaking float valve on a gravity feed engine if leaking bad will cause the engine to run rich and normally blow black smoke as it floods the engine, or if let to set will fill the crankcase in just a few minutes in some cases.