My Johnson 8hp 2 cycle outboard (model: J8RSOR) engine starts cold and runs strong, idles perfectly and runs great at all ranges of throttle. Until you shut it off.
Historically engine always started on first or second pull. Now, no matter how long it is run once shut off sometimes it will restart on the first pull other times it will not start at all. Spark and fuel are there. This all began after the water tube broke off and it was run for a short time not getting strong cooling water, the engine may have got hot?, that problem has been fixed.
A few clues: when this happens plugs seem fouled and wet. Also, on a restart if I pull once or twice and hear sound of a weak “back-fire” sort of a “psssst” sound followed by a shot of gasses and bubbles out the lower-end I know I’m in trouble; it’s not going to restart (I don't recall this pssst thing before the problems started). Only after siting 30 minutes or more after this will it restart.
Something is happening after the engine warms up, could it be electrical? Why would it continue to run strong at normal temp and only present the problem when shut off and trying to restart? After restart, when it does, it runs like a champ strong fast, perfect idle no skips or shakes.
I’ve switched out fuel, rebuilt carb, overhauled the cooling system, new plugs, reset electrical connections, cleaned fuel system lines, still this restarting problem, it’s making me crazy!
Is there a chance I’m losing compression? Could this be a head-gasket causing blow by fouling the plugs? Is that sound I’m hearing a compression leak? Could this be read-valves? Otherwise engine is in beautiful shape, shame this is happening.
Any help greatly appreciated!
Historically engine always started on first or second pull. Now, no matter how long it is run once shut off sometimes it will restart on the first pull other times it will not start at all. Spark and fuel are there. This all began after the water tube broke off and it was run for a short time not getting strong cooling water, the engine may have got hot?, that problem has been fixed.
A few clues: when this happens plugs seem fouled and wet. Also, on a restart if I pull once or twice and hear sound of a weak “back-fire” sort of a “psssst” sound followed by a shot of gasses and bubbles out the lower-end I know I’m in trouble; it’s not going to restart (I don't recall this pssst thing before the problems started). Only after siting 30 minutes or more after this will it restart.
Something is happening after the engine warms up, could it be electrical? Why would it continue to run strong at normal temp and only present the problem when shut off and trying to restart? After restart, when it does, it runs like a champ strong fast, perfect idle no skips or shakes.
I’ve switched out fuel, rebuilt carb, overhauled the cooling system, new plugs, reset electrical connections, cleaned fuel system lines, still this restarting problem, it’s making me crazy!
Is there a chance I’m losing compression? Could this be a head-gasket causing blow by fouling the plugs? Is that sound I’m hearing a compression leak? Could this be read-valves? Otherwise engine is in beautiful shape, shame this is happening.
Any help greatly appreciated!