Rebuild or replace with a new or rebuilt short block? Who has the best deal?

[turbofiat124]

This is one of those "DUH" things. I overfilled my 6 year old 21hp Intek engine during my last oil change. Got distracted, didn't really realize it at the moment. Thought the engine would just burn any excess oil out of the engine and that would be the end of it. Well apparently not.

Now it's burning oil all the time. Fresh oil immediately turns black as coal. Yesterday I was mulching leaves and the engine started to sputter. I pulled the spark plug and it was coked up with ash deposits from where it's burning so much oil. Gave it a good bead blasting in my cabinet and mulched some more.

Apparently overfilling the engine with oil will damage the rings. According to a guy I work with who works on lawnmowers.

I'm hoping I can keep enough "used" oil in this engine to prevent it from seizing up until I can finish mulching up these leaves. Then repair the engine this winter.

Question:

I have not talked to my co-worker to see how much it would cost to fix this engine.

I am mechanically inclined but out of all the things I've done with cars and mowers, I have never actually installed new rings in an engine. Other than putting together rebuilt short blocks and cylinder heads in cars and dropping them in.

I'm not sure if that's all it would take to control the oil burning. Did I screw up the valve seals along with it?

Any chance I just messed up the PVC system and that might be why it's burning oil? I know that there is a diaphragm inside the PVC box on the side of the engine and if it goes bad, it will such oil into the breather and blow oil all over the engine (seen it happen on a Tecumseh) but not sure if that would cause the engine to burn oil. I suppose I could look in the breather and see if I see any excess oil.

Or is that wishful thinking?

Now might be a good opportunity to learn how to install new rings in an engine! But my time is limited.

My idea would be to buy a new short block and transfer all the bits from my old engine over to it myself. Or tear the engine down to the short block and take it to him and have him install new rings or whatever else it needs. To save some money.

Can I even buy a remanufactured short block with or without a core charge?

I'm trying to weigh the cost of someone else's labor versus new parts.

What's my best option?

I don't have the model number handy but it's a 21hp Intek vertical shaft engine. Who has the best deals on shortblocks?

What are some of my other options? Or than buying a used engine?

I actually have a good 15 HP Kolher engine that is on an old Snapper with a seized transmission but don't think it would have the balls to turn the blades on a mower with a 48" dual blade deck.

I tried replacing a seized Briggs 11, 12 or 13 HP (can't remember) engine on an old 1979 Snapper with an 8HP Tecumseh engine and if the grass was more than 6" high, it would stall the engine. So I think the same thing would happen with this Craftsman mower if I drooped down from a 21 to a 15 HP engine. I'm not sure if I want to go that route.

 

[Tinkerer200]

Well in the first place, who mows grass over 6 inches high? The 15 hp Kohler will handle the mower but may not mow grass over 6 inches high. Never heard of over filling an engine with oil ruining rings and I have worked on small engines a long time. I have heard of oil contaminated with gas ruining the engine, usually by throwing the rod. Some in that series of engine had very poor fitting air cleaner resulting in premature ring/cylinder rear. Rings for that engine cost from $35 to $55 per cylinder depending on how good a shopper you are and sump gasket $24 - gasket set about $50.

I have a good used block for that for $20, but would cost that much or more to ship it.

Walt Conner

 

[ILENGINE]

I would be checking for blown head gasket. I don't think the extra oil harmed the engine, other than maybe tried to hydrolock and damaged the head gasket. Or the over fill of oil had nothing to do with the problems you are having.

 

[bertsmobile1]

I would be checking for blown head gasket. I don't think the extra oil harmed the engine, other than maybe tried to hydrolock and damaged the head gasket. Or the over fill of oil had nothing to do with the problems you are having.

A posted above.
Inteks have a very weak head gasket.
I took this up with a B & S rep one time at a mower show type event.
My beef was that the aftermarket gaskets were a lot stronger and rarely blew
He said it is intentionaly weak so in situations like yours, the gasket will blow rather than breaking rings or cracking heads.
Flimsey excuse for an inferiour design or genuine safety feature , you decide ?

Easy job to replace head gasket.
Biggest PIA is removing the silicon on the rocker cover.
Generally I replace it with a real head rocker gasket which allows me to do regular valve lash checks without having to spend 45 minutes each time cleaning off the old sealant.

 

[turbofiat124]

Well in the first place, who mows grass over 6 inches high? The 15 hp Kohler will handle the mower but may not mow grass over 6 inches high. Never heard of over filling an engine with oil ruining rings and I have worked on small engines a long time. I have heard of oil contaminated with gas ruining the engine, usually by throwing the rod. Some in that series of engine had very poor fitting air cleaner resulting in premature ring/cylinder rear. Rings for that engine cost from $35 to $55 per cylinder depending on how good a shopper you are and sump gasket $24 - gasket set about $50.

I have a good used block for that for $20, but would cost that much or more to ship it.

Walt Conner

I have about 10 different types of grass on my property (about 2 acres). I work 12 hour shifts and have to mow between my job and the weather which is about every 2 weeks. The grass around my house is zoysia grass so it only needs mowing once every 2 weeks which about how often I mow my yard. The grass beside my garage is Bermuda grass so it grows the most rapidly. Then I have regular field grass.

Like I said I read some wrong info on the web where it said to add 2 quarts to a 21HP Briggs engine. Maybe I can upload the PDF file from my main PC to here. In reality it requires about 1 quart. There must be two different types of 20+HP Brigs motors out there. One that takes 1 quart and one that takes 2 quarts. The Intek is only 1 quart.

My Father's John Deere 54" has a 20+ HP engine and it does in fact require 2 quarts of oil. I made absolutely sure I did not overfill his engine yesterday. I have no idea who makes the engine for a John Deere (I assume it's a B&S). It has John Deere stamped on the engine cover.

 

[turbofiat124]

A posted above.
Inteks have a very weak head gasket.
I took this up with a B & S rep one time at a mower show type event.
My beef was that the aftermarket gaskets were a lot stronger and rarely blew
He said it is intentionaly weak so in situations like yours, the gasket will blow rather than breaking rings or cracking heads.
Flimsey excuse for an inferiour design or genuine safety feature , you decide ?

Easy job to replace head gasket.
Biggest PIA is removing the silicon on the rocker cover.
Generally I replace it with a real head rocker gasket which allows me to do regular valve lash checks without having to spend 45 minutes each time cleaning off the old sealant.

Well that makes me optimistic. I will try replacing the headgasket first. I did overfill the engine by 1 quart.

But help me understand something. I have never had the head off an Intek engine. Just the older B&S motors. I did not think there were any oil galleries in the cylinder head/combustion chamber on an air cooled lawnmower engine. But those older engines were not OHV engines.

I guess I'll see what's behind the head when I pull it off. I have seen older B&S engines leak oil from worn rings/weak head gaskets. As if the oil leaking passing the rings instead of getting burned, is forced through the head and headgasket.

So I maybe contradicting myself....

I am skeptical of the quality of B&S motors these days. I had a 2000 Snapper with a 14 HP B&S. It threw a rod after maybe 5 years. Best I can tell the connecting rod nuts vibrated loose and sent the connecting rod through the block! As if the factory neglected to install Lock-Tite on them. I've still got photos on my main PC to show what happened. I'll try to dig them up.

I ended up buying a used Kolher 14 HP and ran it until I sold the mower last year.

If I had a choice, I would not buy a new mower with a Briggs engine. The only reason I bought this mower was I got a good deal on it and Sears and knocked about $300 off it.

 

[ILENGINE]

Turbo, the single cylinder and somewhat the V twin briggs engines have a large open cavity where the push rods are and about 1/4 inch separates the cylinder from that cavity. It will blow the head gasket in that narrow area, and causes crankcase pressure, as well as causing a vacuum which sucks the oil into the cylinder when the piston goes down.

 

[bertsmobile1]

Big snip
So I maybe contradicting myself....

I am skeptical of the quality of B&S motors these days. ?????.

If I had a choice, I would not buy a new mower with a Briggs engine. The only reason I bought this mower was I got a good deal on it and Sears and knocked about $300 off it.

Well that is exactly why quality drops.
Customers buy stuff because it is cheap at the time
You get to a point where the only way to produce cheaper engines is to drop the quality.
Then it becomes an endless feed back loop spiraling down the collapse of the company.
Tecumseh is a perfect example of this endless quest to produce the absolute cheapest product.


As for "Intek" that is just the name of a design type off B & S engines.
The Inteks are ( or were ) the lowest price, thus poorest quality engine built for low end ( domestic ) products so Sears ( and others) can sell them cheaply to people who either will not pay for good quality or can not recognise quality.

And bfore all the readers with no understanding of economic history scream about how many thousands they spent on their mower, convert the $ price into week / months wages and you will see a ride on is about 1/2 the price it was 10 years ago and about 1/10 th the price of the 70's.

 

[Tinkerer200]

How long an engine lasts depends a lot on the owner. We have a neighbor who has a JD with an Intek twin engine on it about 7 - 8 years old which he uses for commercial mowing and has no trouble with it but he is very meticulous with his maintenance.

Walt Conner

 

[Rivets]

This manual may help you out.

https://doc-0o-5o-docs.googleuserco...253/*/0B6NaqjIxWV1ySkZjTTA5TGltZEE?e=download