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SteveP

16 hp Vangaurd

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Eddie
Well SPec what i would do if I were you is first buy a knew head gasket, then see. If that doesn't work take a compression test. Once you get that reading from both cylinders, do a wet compression test. That is when you put a little bit of oil in each cylinder, then re take the test. If the compession goes up then your rings are bad. Your rings would be bad because when you put oil in the cylinders the oil fills the gaps between the piston and the rings. If you end up ripping your 16hp apart take a feeler gauge if you have one and put in between the rings and the piston. See how many thousands of an inch of clearance you have. But getting back to the test, if your wet compression test stays the same as your first compression test then it would come down to being your valves. Inspect your valves and see what the problem may be. Good luck on your 16 horse and by the way if the valves are good I would then take the engine apart and see if you had a broken ring, but don't neglect the obvious first see if you have good compression, I hope it all works out for you. I took my 1972 Simplicity Yeoman out today and she is running great. Next winter I'm taking the engine off to put a knew crank shaft in and hone the cylinder out, and put bran knew piston rings in, well good luck.

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SteveP
Still having problems with my 16hp Vangaurd. I replaced the broken rocker, but in the mean time had notice what I hoped was just a related problem. In the other cylinder I notice a lot of raw oil. Hoping it had been force somehow from extra pressure caused by the exhaust valve not opening on the other cylinder. Apparently not :( Now the question. What can it be. Blown head gasket? Broken rings? Complete rebuild? I know the only way to really tell is to tear into it but any words would be very appretated.

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Al
Hi, If you have a lot of oil in the cylinder, I would first try to determine where it is getting in. First I would disconnect the rubber hose from the breather to the aircleaner. Start the engine and rev it up and see if any oil is coming out ot this hose. If so, one of 3 things is happening. 1 The crankcase breather is bad. [assuming the engine is not over full of oil or has a crankcase full of gas] 2 There is a crankcase leak. 3 There is either a head gasket leaking into the oil return or the push rod area or you have a lot of blow by into the crankcase form the cylinder. First step is to hook a manometer to the crankcase. If you don't have access to one you can use a vacuum guage and convert inches of vacuum to inches of water. [Use and old dipstick cap and epoxy a hose adaptor in it[ With the engine wide open I would expect to see at least 10 to 15 inches of water. If you are seeing very good crankcase vacuum, I would next check the cap of the dipstick, there is a square o-ring to fix a crankcase leak there. [I'll try to get the part # tomorrow.] If you are getting a low reading I would use a leakdown tester on each cylinder and see if the leakdown is normal. [check to see that the tin ducting around the cylinder isnot under the edge of the valve cover causing a leak.] Then I would do a compression check. If the compression is over 100 lbs your tappets need to be set. If that is good I would probably [take a chance] try replacing the crankcase breather and see what that does for the crankcase vacuum. If if don't help I would pull the heads and replace the crankcase gaskets. We have seen some of these engines that had good compression and passed the other tests and had head gaskets leaking into the crankcase and they would blow oil into the carb. Even when you look at the gaskets they look good. Check the head surfaces for flatness use and straightedge and if a 002 guage will clear,you need to resurface the head , [check the block surface also] If head is not flat, use a thick sheet of glass or a ground flat plate and some sandpaper 120 or 180 grit and "lap" the head. Slide it on the paper, turn it 1/4th turn, a stroke, 1/4th turn rotate, stroke etc until is is flat. Put new head gaskets in by the [Briggs] book and you should be in business. Most of the engines we have seen with this problem have been head gaskets, and many of them you could not verify the leak by looking at the gaskets and seeing the leak, they also had good compression. My only other thought is why did the rocker break? Was it due to oil lock in the cylinder? Maybe if there was a lot of oil in the cylinder and when the valves were just closing and the cam was still tight on the lilfter the oil which is non compressable forced the valve again the rocker and broke it. Maybe it just broke and the other stuff is secondary. When the tappets get too loose in all Briggs engines they get so the starter will barely turn them over. This is bcause the compression is a bump on the cam that lifte the valve off the seat slightly on the compression stroke and when the valves are too loose this don't happen. Then these little starters don't have the torque to turn the engines over. Good luck on this and let us know what you find. Al

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