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Replacement for a Quantum engine on a rotary mower

#1

T

theoldwizard1

The engine on my Toro Super Recycler is using oil. I don't think it will last much longer. The rest of the mower is in excellent shape.

B&S made some major changes to the replacement engine. The carburetor and muffler are now on opposite sides !

How hard is it to attach the throttle and brake cables ?


#2

Scrubcadet10

Scrubcadet10

What is the model number of the quantum on it now, might could find a shortblock.
you just swap over all external components to a new engine block with internals.
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#3

T

theoldwizard1

Scrubcadet10 said:
What is the model number of the quantum on it now, might could find a shortblock.
you just swap over all external components to a new engine block with internals.
View attachment 69509
Click to expand...
Great idea (and reasonable price) !

Model Type
128802 - 0615 - 01

Unfortunately that has a 1" x 3-5/32" shaft

Small Engine Warehouse says they don't have any short blocks that meet those specs.


#4

T

theoldwizard1

theoldwizard1 said:
Unfortunately that has a 1" x 3-5/32" shaft

Small Engine Warehouse says they don't have any short blocks that meet those specs.
Click to expand...
Crazy idea !

I I can get the specs on the snout for that crank shaft, I can make an adapter !

Where can I get specs ?


#5

Scrubcadet10

Scrubcadet10

theoldwizard1 said:
Crazy idea !

I I can get the specs on the snout for that crank shaft, I can make an adapter !

Where can I get specs ?
Click to expand...
you can choose engines by crankshaft sizes on small engine wharehouse


#6

T

theoldwizard1

I can buy a new short block (sb799982) for that engine for under $100, then I can buy a NOS crank for under $100. Am I crazy to swap a crank on a brand new engine ?

Or should I just buy a Predator ?


#7

M

MParr

Are you sure that’s a 1” diameter crankshaft? 25mm is just short of 1”. 25mm = 0.984”


#8

T

theoldwizard1

MParr said:
Are you sure that’s a 1” diameter crankshaft? 25mm is just short of 1”. 25mm = 0.984”
Click to expand...
It measures 1.0", but the specs say 25 mm. Go figure.


#9

T

theoldwizard1

Scrubcadet10 said:
you can choose engines by crankshaft sizes on small engine wharehouse
Click to expand...
I called them and they had no short blocks of that engine with 1" shaft.


#10

M

MParr

theoldwizard1 said:
It measures 1.0", but the specs say 25 mm. Go figure.
Click to expand...
It probably is 25mm. Did you measure with a micrometer? 25mm is 0.016” less than 1”.
I had the same mower and it was equipped with the B&S 6.75 190cc engine.
It doesn’t matter if you buy an engine with a 7/8” shaft, as long as the shaft is the correct length. All you will need to do is change out the engine pulley for the self propelled system.


#11

O

Oddjob

Wizard, if I were you I’d keep an eye on Craigslist for someone giving away a mower with a good engine and a rusted out deck or sometimes even a good mower with nothing wrong but a dirty carburetor. Or, visit your local recycling center and see if you can score an engine there. Since your Toro is still useable you have the luxury of waiting for one to turn up. I see free mowers in my Craigslist every couple of weeks. The Briggs on your Toro is very popular and there are lots of them out there.


#12

T

theoldwizard1

Oddjob said:
Wizard, if I were you I’d keep an eye on Craigslist for someone giving away a mower with a good engine and a rusted out deck or sometimes even a good mower with nothing wrong but a dirty carburetor.
Click to expand...
That is what my son said ! I was hoping to not buy a used one, but ...


#13

E

Erubi

I replaced the B&S Quantum on my Snapper with HF Predator making adjustments for mounting and crankshaft size and it works fine. Amazon also sells a similar engine. I would suggest a coupon or sale.


#14

O

Oddjob

theoldwizard1 said:
That is what my son said ! I was hoping to not buy a used one, but ...
Click to expand...
Remember, the engine you had that ran well until it began to smoke was a used engine and the mower you are installing it in is a used mower, too. And the new Predator will be a used engine as soon as you mow with it. Most mowers get taken out of service because they were left out in the elements or had clogged carbs or bad fuel or a stuck choke, not from being used and worn out.


#15

T

theoldwizard1

Erubi said:
I replaced the B&S Quantum on my Snapper with HF Predator making adjustments for mounting and crankshaft size and it works fine.
Click to expand...
Details PLEASE !


#16

E

Erubi

theoldwizard1 said:
Details PLEASE !
Click to expand...
I posted my journey back in 2017. There are also a lot of YouTube videos on the process.


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