1982 5hp, spark plug very wet and black, engine popping

Hammermechanicman

Lawn Addict
Joined
Jan 10, 2020
Threads
49
Messages
3,484
  • / 1982 5hp, spark plug very wet and black, engine popping
I don't think think you have a spark issue. If the engine has a lot of hours on it it probably has worn valve guides which is just holes in the aluminum block. This is a weak point on that 5hp engine. Take the head off and check for side play in the valves. Should be very little. If guides are worn new brass guides can be installed by a shop if the have the tools. Haven't used mine in many years. Oil in the exhaust is either worn rings and cylinder or the crankcase breather is plugged. On the side of the block is a cover to access the valve springs. This is the crankcase breather. It has a disk valve in it and 2 oil drainback holes. If the valve it stuck or the holes plugged you will get oil in the cylinder. If the oil was not changed on a regular basis that aluminm bore engine will probably have a worn cylinder. It can look smooth but have low compression. Because of the easy spin bump on the intake lobe of the cam a compression tester won't tell you much. You need to do a leakdown test to determine the condition of rings and valves and that won't find bad valve guides. If you really want to save it you can get the proper ball hone and deglaze the cylinder and put in new rings and have new guides and valves installed. Will cost more than the tiller is worth probably. When you replaced the valve cover did you orient the drainback holes at the bottom? And the gasket nitches at the bottom? If not it will fill with oil and blow oil into the cyoliner
 

slomo

Lawn Addict
Joined
Jul 14, 2019
Threads
76
Messages
4,677
  • / 1982 5hp, spark plug very wet and black, engine popping
Is the oil over filled? Valve seals might need replaced. Oil rings might be bad.

slomo
 
Top