View Full Version : First time repair

06-22-2007, 01:49 PM
I'm working with a four stroke Tecumsah motor, model no. 143.004002;
family YTPXS.1631BA:
So, I go out to mow the lawn at the beginning of the season and the mower won't work. It has this distinct clack! sound approximately every 3/5ths of a second.
I get to the task of taking the thing apart, a first time endeavor for me, and now I'm stuck.
I thought it was a flywheel timing thing, that the magneto was sending electricity to the plug prematurely; however, when I noticed that the (unbroken) flywheel key, and thus the rest of the flywheel, seem to be aligned at a set spot on the drive shaft (that the flywheel key connects the flywheel to the drive shaft at one, and only one, location) I wonder if it is the case that flywheel can be aligned differently.
If not, where should this pronounced "Clacking" be coming from?

Also, I removed the bottom plate from the drive shaft. Is there something that I had to do while reinstalling it to ensure that I recreate an oil tight seal?

Thanks for the Help

06-22-2007, 04:04 PM
That's one of those rod throwing Tecumseh's. I would suspect the rod or oil pump is ready to shoot through the side of the block. Also that is a Sears #
Go here and type in your sears model number.

Bill Kapaun
06-22-2007, 07:49 PM
Your engine should be a Tecumseh-

You can get a service manual here-

06-23-2007, 08:58 AM
Cool, I'll be checking on the rod and reading through the shop manual. Thank you for the posts.

06-25-2007, 12:32 AM
After taking this modest beast apart again, the only thing that I noticed was some somewhat excessive play on the crankshaft. Unfortunately, it was not the connecting rod which looked undamaged; the oil pump too seemed sound.
A note: Although I'm positive that there is a tool for this, I found that using a worm gear clamp to fully constrict the piston compression rings made reassembling the piston doable.
"Experience increases like revolution of time.":rolleyes:

06-25-2007, 01:37 AM
Ring compressor is what it's called. A worm clamp over a piece of sheet metal works too. Glad you got it together. What type of crankshaft play are you speaking of?

06-25-2007, 10:35 PM
Oddly enough, the flywheel seems to be somewhat unseated. The key doesn't look shorn in any way, though, to be truthful, I've never looked at a shorn flywheel key. when you lift the break from the inner flywheel rim, you can slide the crankshaft over two centimeters up and down. So, the unseated flywheel is causing an amount of vertical play in the crankshaft, which in turn, I'm presuming, is affecting the rod, valve timing gear, and all other connected parts as well. A tight blade is all that keeps the whole thing from gyrating to oblivion.!

Bill Kapaun
06-25-2007, 11:51 PM
2 centimeters is .8"!
Sure you don't mean millimeters?

06-26-2007, 03:11 PM
Apparently this is quite a bit of play that I'm experiencing. "WHERE'S MY HAMMER . . . !":clapping: