need a little help troubleshooting a sears self propelled

[robramm]

I Have a 10 year old sears self propelled with a Eager1 craftsman 4 stroke engine. I change the oil every year and its never down. I got a little lax in checking oil. Last cut of the season, I was half way through when the engine started to slow down quite a bit. I thought it was just bogged down, so I stopped moving forward and the engine stopped, but sounded like the flywheel up top kept spinning for a good few seconds before it stopped. I then checked the oil and it was for all intensive purposes dangerously low.

I filled it back up with oil, then pulled the cord and it seemed to pull normal, but no compression. I then pulled the plug out to see if the piston moved or if it was seized. When I turn the cutting blade, the piston does not move, nor is there any resistance (blade turns freely) Could it be just the flywheel key? or something more serious like a broken rod. I didn't hear anything out of the ordinary other than it slowing down. No bangs but almost like the timing was off maybe? I don't know why the key would have busted as I didn't hit anything.

Can anyone give me a clue as to if this is worthwhile digging into by what I've told you and if so, where would you start? I'd like to just get it going long enough to make a couple more cuts.

Thanks,
Rob Ramm

 

[KennyV]

Hello Rob & WELCOME to LMF...

When you turn the blade... Is the crank shaft that is attached to the blade also turning??

If you actually heard the flywheel spinning after the engine stopped, then the flywheel is definitely sheared.
But it is more likely that you were hearing the blade and adapter spinning... in any case, either the top (flywheel) OR bottom (blade adapter & blade) is not attached to the crank... Possibly both.

If the flywheel key is sheared, pulling the starter rope will not turn the engine....
So the starting place is check the top & bottom to see what is no-longer connected...

If the engine is seized it may not be worth the rebuild... but I would still take it apart to verify what all has been damaged... But I personally like rebuilding things. Especially older things that I LIKE. :smile:KennyV

 

[robramm]

Hello Rob & WELCOME to LMF...

When you turn the blade... Is the crank shaft that is attached to the blade also turning??

If you actually heard the flywheel spinning after the engine stopped, then the flywheel is definitely sheared.
But it is more likely that you were hearing the blade and adapter spinning... in any case, either the top (flywheel) OR bottom (blade adapter & blade) is not attached to the crank... Possibly both.

If the flywheel key is sheared, pulling the starter rope will not turn the engine....
So the starting place is check the top & bottom to see what is no-longer connected...

If the engine is seized it may not be worth the rebuild... but I would still take it apart to verify what all has been damaged... But I personally like rebuilding things. Especially older things that I LIKE. :smile:KennyV

Hi Kenny,

I never thought to check that thanks. Yes, you are correct, When I pull the rope, the blade spins, but the piston does not move. From what I understand then, the blade is then not connected to the crank? I did put a bit of penetrating oil in the spark hole to let it seep through over night incase It is a bit seized so I don't have to wait if it is.

I can't quite visualize how it is all connected. Its been a few years since auto shop lol

Is there such a thing as a sheer pin on the blade? I thought if an engine ran out of lubrication, it would heat up and seize, not separate from the crank, or maybe the oil is unrelated?

So since the blade spins when I turn the rope,but the piston doesn't move when I turn the blade, where do you recommend me going in for a look see?

I'm getting that eager feeling I used to when I was a kid when I took something apart for the first time

...Rob

 

[fifthstring27030]

Hi Rob
If you pull rope and blade turns everything is connected to crankshaft. Flywheel key does not even have to be in crankshaft as long as it is tight. All it does is set the timing of the spark. I am sorry to say you have a broken connecting rod. that is why the piston does not move when you pull rope. When engine was bogging down it was probably the rod seizing to crank from lack of oil. It is not that bad of a fix if engine block is not damaged. A new rod is not that expensive and the crank should be ok all that usally happens is transfer of aluminum from rod to crank. A little emory cloth and you can polish crank right back. Look closely at bottom of cylinder to make sure is not damaged. Good Luck

 

[KennyV]

Oh Ooooo....
Rob... this is Not sounding good...
fifthstring27030 is right.. if the crank is turning but the piston is not moving. They are no longer connected.The low to out of oil condition without any doubt is very much related... Unfortunately now is the time to open it up... but maybe not so much for a repair but to survey the damage and go from there...
Open it up and tell us what you find... I have a good guess but nothing beats an actual look see....
the only 'good' thing, it's at the end of this mowing season.:smile:KennyV

 

[robramm]

Heh Heh, Thanks a lot. This gives me some closure. After inspecting the condition of this 10 year old mower (needs new belt, 4 new wheels because the teeth are worn and will soon not propel, the front bering for the belt drive that makes it go faster is broken and not available (been operating at 2/3 speed for 5 years now), both sides of the handles where bolts go through snapped which I have fixed by sliding a similar size tube over and secured, Oh, and did I tell you it leaks a bit of oil LOL (new issue just discovered )
It also needs a new blade so I think I'll call it a life.
I'll still tear it down though just to see what happened.

If it would have broke 2 weeks earlier I would have hit all the clearance sales that EVERY store told me about just after they said they have no mowers in stock LOL. Well, it is the end of the season and it will give me some time to research a new one. Leaning towards a club cadet with honda engine and maybe front casters.
Open your suggestion to your favorite mower under $500. Its just tough finding one with rear drive and one lever wheel adjustment. These are a must have

Well, if there is one lesson I learned is to now check the oil every fuel up. Thanks for teaching me this lesson on my 10 year old craftsman and not my new pony.

Thanks to all for the support.
...Rob

 

[flyerdan]

I've got an old beater mower that I got free about 20 years ago, I use it for mowing the street side and chopping up leaves in the fall. Last winter just as I was finishing up the last of the leaves it threw a rod, make a bang and that ticking sound a radial engine makes on shutdown.

Not at all surprised at what I found, fortunately I had a spare rod and piston hanging above the workbench. Didn't tear any gaskets or seals in the process so it didn't cost anything. Deck is all patched up with sheet metal and the bag has been sewn up with fishing line. Mowed up several bags of leaves yesterday.

 

[KennyV]

Hey Rob... You may get lucky like flyerdan and find only the rod damaged... could go back together with very little cost... and give you many more years use... :smile:KennyV

BTW... nice picture, flyerdan... always amazing how things can break up so quickly....

 

[robramm]

Great pic.
Yes, that would be great if it only broke a rod. Haven't tore into it yet. Been dealing with family stuff last few days and have to go abroad, so it will have to wait till I return.

 

[Mini Motors]

I have a hard time believing a 10 year old anything from Sears has NLA parts. I've bought parts for 1954 Craftsman shop tools.