It looks like one of the flyweight lugs (on the governor) has jumped out of its slot. The governor assembly is supposed to touch the underside of the flywheel when the mower is not running. As the motor runs it is pushed down. The exhaust ports look OK to me. The kind of cast aluminum muffler on your model seldom gets plugged up, it will be very obvious if it is. A coating of carbon on the inside of the muffler does no harm. A motor that old can certainly be low in compression. A new set of rings is relatively inexpensive. You should make sure the governor assembly can push down on the crankshaft easily and in doing so moves the throttle butterfly lever on the carb. This all needs to work smoothly.
Lawn Boy 5236 Low Power Problem
- Thread starter rev20
- Start date
Guys,
I found someone else to help me clean the carb. After cleaning it, the mower seems to start well without any problems. However, it still struggles when I get to the grass. Do you think a new set of rings could cure the problem? Also, is there a way to know which rings to buy without removing the piston and reading the numbers?
Thanks!
I found someone else to help me clean the carb. After cleaning it, the mower seems to start well without any problems. However, it still struggles when I get to the grass. Do you think a new set of rings could cure the problem? Also, is there a way to know which rings to buy without removing the piston and reading the numbers?
Thanks!
bt3
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Possibly but not probably in my opinion. Did you do a compression test, or can you? I'd only suspect rings if you had measured poor compression. A more common cause of low power (assuming you are confident you tackled Governor, muffler/exhaust ports and have good Carb and Spark going) is the bottom crankcase seal. If this seal is leaking it will rob you of power. Between lower crank seal, governor, carb and spark those would be my first hits on loss of power. Lastly would be piston rings. However, IF they are worn and IF you are losing compression because of them, then this could possibly be a suspect of your issue on power loss.
I've had loss of power issues due to magneto/spark issues, carb, governor and crank seal. I've had start issues because of the same plus Reed valve. I've not yet had to replace the piston rings, but it's probably on the horizon at some point as I'm not parting with my LawnBoy.
I did the compression test by pushing the flywheel and then observing if there was a rebound. When I got one, i concluded that there was compression. Is there any way to know if the seals are the problem or a better way to do the compression test? Also, is the presence of oily substance on one side of the muffler a sign that the seal is leaking?
You don't need specific numbers to order rings for late model "D" engines. Here is a link:
Piston Rings Replaces Lawn-Boy: 678422
beg
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I had the same d motor did the same thing you described did all the things mentioned in the posts.If you have good compression check the needle and seat in the carb.yeah thats what it was after hours of tinkering around.but unfortunately you have to rule out all possibilities.