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Snapper 28” rear engine

#1

L

Larrychack

My snapper with the Briggs 12.5 hp using a mulching blade doesn’t have enough hp. I would like to change the engine to a higher hp but don’t know what size and bolt pattern will fit on a 28” frame. Does anyone have info regarding an engine swap out.


#2

R

Romore

I replaced a couple of blown 9hp on Snapper 28" mowers with 12s, those things would slay thick couch grass over a septic field. Are you trying to cut thick, damp grass? You need to mow frequently to successfully mulch, only take off the top third of the blade.


#3

L

Larrychack

I replaced a couple of blown 9hp on Snapper 28" mowers with 12s, those things would slay thick couch grass over a septic field. Are you trying to cut thick, damp grass? You need to mow frequently to successfully mulch, only take off the top third of the blade.
I never cut when grass is damp or wet. I’m cutting st Augustine grass and with the mulching blade I have to run in 1st or 2nd gear position. That mulching blade seems to suck up the HP. I really don’t let the grass get very tall before I cut. I guess I’m used to the Craftsman 46” with a 25 HP Kohler (with mulching blade Also) that I use at my camp.


#4

S

slomo

Either you are cutting off to much grass at one time or that blade is dull. Mulching blades are the easiest on fuel slash engine load.

Also check to see if you are getting your full 3600rpm at fast/high throttle or what ever your manual states for max revs. Some mowers like Hondas run from the factory at 2500rpm. People are amazed at how quiet they are...... Turn one up to 3600, different story.

Do you have good fuel and spark? Compression? Valve adjustment time?

slomo


#5

K

keakar

My snapper with the Briggs 12.5 hp using a mulching blade doesn’t have enough hp. I would like to change the engine to a higher hp but don’t know what size and bolt pattern will fit on a 28” frame. Does anyone have info regarding an engine swap out.
just about any single cylinder B&S fits it, it has the same bolt pattern for the older metal top cover engines as the new inteks have as well, also kohler engines up to around 15hp i know fit it

find a craftsman or murray lawn tractor for sale cheap that needs a deck and swap that engine into your snapper because most of those will be in the 14hp-17hp range. you can buy mowers with good engines that have other issues for around $100-$150


#6

L

Larrychack

just about any single cylinder B&S fits it, it has the same bolt pattern for the older metal top cover engines as the new inteks have as well, also kohler engines up to around 15hp i know fit it

find a craftsman or murray lawn tractor for sale cheap that needs a deck and swap that engine into your snapper because most of those will be in the 14hp-17hp range. you can buy mowers with good engines that have other issues for around $100-$150
Thanks. I didn’t realize that the higher hp single cylinder engines had the same bolt pattern as the 12.5hp. I’m assuming the crankshafts are the same diameter also?
i think I can get my hands on a rider mower with a bad deck or transmission at a decent price.


#7

Scrubcadet10

Scrubcadet10

Crankshaft Length and diameter needs to be the same...
Find the engine Model number, contact B&S , they should get it for you.


#8

L

Larrychack

Crankshaft Length and diameter needs to be the same...
Find the engine Model number, contact B&S , they should get it for you.
Thanks.


#9

K

keakar

Thanks. I didn’t realize that the higher hp single cylinder engines had the same bolt pattern as the 12.5hp. I’m assuming the crankshafts are the same diameter also?
i think I can get my hands on a rider mower with a bad deck or transmission at a decent price.
you use the same bolt pattern right up to the B&S 16.5 hp i think and then when you get to the B&S 17.5 hp and up range the pattern changes


#10

B

bertsmobile1

I never cut when grass is damp or wet. I’m cutting st Augustine grass and with the mulching blade I have to run in 1st or 2nd gear position. That mulching blade seems to suck up the HP. I really don’t let the grass get very tall before I cut. I guess I’m used to the Craftsman 46” with a 25 HP Kohler (with mulching blade Also) that I use at my camp.

Mulching actually uses more Hp than plain old throwing but less than bagging .
How much depends upon how much grass is kept in suspension above the blades
You will find a Gator® style blade will mulch better with less Hp drain than the std mulching blade
I fitted 4 high lift blades onto a 12-36 thinking it would throw the grass further
All it did was accumulated a massive amount of grass above the blades and bogged the mower no end.
IT takes a lot of energy to defeat gravity

As the mores get longer strokes, they get longer cylinders.
So the bolt pattern will be fine but the engine might not fit within the body work and the muffler might end up in a funny position.
A local make down here Greenfields decided to offer a bigger engine then found that the bigger engine would not fit in their frame so they had to turn it sideways so it cooks your left foot
Rover did the same thing but they turned the engine backwards which overheats the gravity feed fuel tank.

Sites like Repower , Small Engine Supplies & Small Engine Warehouse all have links to manufacturers sites so you can look up the line drawings of all of the engines, current & out of production.
Thus you can check the width , height & length of the engine you are considering using.


#11

L

Larrychack

you use the same bolt pattern right up to the B&S 16.5 hp i think and then when you get to the B&S 17.5 hp and up range the pattern changes
Thanks very much for the info.


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