John deere 624 snowblower Engine oil issue

[yelbike]

I inherited a jd 624 snowblower from my dad. He's not real big on maintance. So after changing the belt that were completely worn(probably original) the blower worked really well. So I would like to keep this thing around as a back up as it has electric start.
So I was blower snow with it a couple of years a ago and it ran out of oil. I useally check the oil every time I use an engine. Of course this time I hadn't. So the engine siezed.Being all curious I took the engine apart and found the smallest burr on the connecting rod and the crank journal. Ever so lightly filed the burr off and now the engine was good to go. I put everything back together and the **** thing worked good again to my surprise. :cool2:I'm not a engine mechanic.

So I was blowing snowing on its second pass I noticed engine oil was being forced out of the (I think) reed valve. I quickly shut It down and haven't touched it again.

The engine is tecumsech 6.5 hp about 1976 vintage. On the "rebuild" I changed at least one ring, maybe all three (can't remember). But I did not hone the cylinder. I think what is happening is the air is bypassing the seal of the rings and pressuizing the oil bath case to the point of forcing the oil out the reed valve (crankcase vent). I was thinking that if I take it apart again and hone the cylinder this time I should be Ok. Am I on the right track or way out in left field?
Also I could just slap a new engine on if I really had to but then it wouldn't such a collectable as the paint wouldn't be yellow!:laughing:
Thanks for the advise ahead of time.

 

[yelbike]

Bump up. Is there any hope for this engine or should I replace it?

 

[beenthere]

Certainly can't give you the answer you are looking for. Once siezed there may be other mitigating circumstances that might mean the engine is toast or that a complete rebuild is in order. A price to pay for not checking the oil. Sorry, but no good news that I can see.
You may get lucky with your plan to hone the cylinder, and could be worth a try. Wish you well.

 

[yelbike]

The second time around the engine did not seize. I saw the oil pumping out, so I shut it down. I believe this is what happened the first time except I didn`t see the it happen. I`m just wondering why the oil would pump out like that.

 

[beenthere]

I would guess the sieze the first time around left some residual damage that you have yet to find.

 

[tomd999]

Hi,

So, let me get the facts correct, you got the snowblower several years ago, ran it out of oil, seized it, pulled it down, fixed it, let it sit for a couple years and now fired it back up and on the second pass, it starts blowing oil and you shut it down? Or did you run it for a couple seasons in between incidents?

As far as oil blowing out the breather, the older Sno-King series engines used a fiber resin disk as a valve on the breather block with a very light rate spring to tension it. You can pull the block out and make sure the disk valve is on the top as the breather can be put in upside down on the smaller series engines. They will pump out a lot of oil if they are upside down or the spring has broken and not seating the disk.

Also, if you are using a heaver weight oil than specified, the fiber disk has trouble returning to it's seat and it will throw out some oil.

Another common reason they pump out oil is the engine is over filled with oil which is easy if the wrong dip stick is in the engine. Remember, proper oil level for all small engines with a dip stick is BETWEEN the full and low marks.

Normally small engines won't run if they are putting enough cylinder pressure into the crankcase to blow out oil as they don't have high cylinder pressures being flat heads with about a 7-1 compression ratio.

My 2 cents and as always, a total WAG as I havent seen the engine,

Tom

 

[yelbike]

Hi,

So, let me get the facts correct, you got the snowblower several years ago, ran it out of oil, seized it, pulled it down, fixed it, let it sit for a couple years and now fired it back up and on the second pass, it starts blowing oil and you shut it down? Or did you run it for a couple seasons in between incidents?

As far as oil blowing out the breather, the older Sno-King series engines used a fiber resin disk as a valve on the breather block with a very light rate spring to tension it. You can pull the block out and make sure the disk valve is on the top as the breather can be put in upside down on the smaller series engines. They will pump out a lot of oil if they are upside down or the spring has broken and not seating the disk.

Also, if you are using a heaver weight oil than specified, the fiber disk has trouble returning to it's seat and it will throw out some oil.

Another common reason they pump out oil is the engine is over filled with oil which is easy if the wrong dip stick is in the engine. Remember, proper oil level for all small engines with a dip stick is BETWEEN the full and low marks.

Normally small engines won't run if they are putting enough cylinder pressure into the crankcase to blow out oil as they don't have high cylinder pressures being flat heads with about a 7-1 compression ratio.

My 2 cents and as always, a total WAG as I havent seen the engine,

Tom

It was the second pass after the "pull down". It now has been sitting for a couple of years.
The breather is on the side not the top of the engine. The spring looks complete and the reed vale is metal not fiber.

 

[tomd999]

Hiya,

OK, you have the steel disk breather, that's the very early style. What I meant by the breather on top was that it is possible to insert the breather block into the engine 180 degrees out so that the disk would be on the top and the oil would flow down through the filter and out the vent pipe. The breather should be installed so the disk is on the bottom and the vent pipe exits the top, this way the oil has to go "uphill" through the filter mesh to get out.

Another thing to check is the small drain holes on the bottom of the breather block and in the engine case as well, if these are blocked, you'll pump oil out. I don't have a breather in front of me but if I remember right, the drain hole is on the gasket edge and if you put the gasket on upside down, it plugs the oil drain.

Again, a WAG as I can't see the engine,

Tom