Briggs and Stratton 12 HP Motor replacement

 Hi,

I have a 5 year old Murrary 12HP. 38 (or 40)" riding mower .. and I
want to keep it
simply because last year I moved and I bought a rear bagger that works
really well and if I got rid of  it's another $1800 or so to replace
the whole setup.

My main problem is it tends to lose power after awhile .. 15 or 20
minutes.
I've replaced the spark plug and fuel filter .. but I haven't had it
looked at by
real small engine repair place simply because it takes *weeks* to get
these
things looked at ! I's a headache getting it to a shop because it needs
trailered.

I use to have a Sear 15HP it that thing hauled ass .. until I bent the
crank shaft
and ruined the engine.

This Murray is slow .. and even in 6th gear ... It's slow .. Then it
gets slower after 15 minutes !

Whats the possibility of replacing the engine with a new one , and
maybe even larger size ?

PS: The muffler kept falling off and in my 2 attempts at repairing THAT
issue the mounting
holes are ruined and I run without a muffler too. It was running slow
before that happen however.
Now I have a SLOW and LOUD mower !

  Pretty good. Check Northern Tools, they supply small engines such as
this. You may be surprised how expensive motors are.

If you'd like, we can offer some ideas what the low power problem
might be. I've got a few ideas right off the top of my head.

No ideas come to mind for the muffler, though.

--

Christopher A. Young
  You can't shout down a troll.
  You have to starve them.
.

wrote in message
Hi,

I have a 5 year old Murrary 12HP. 38 (or 40)" riding mower .. and I
want to keep it
simply because last year I moved and I bought a rear bagger that works
really well and if I got rid of  it's another $1800 or so to replace
the whole setup.

My main problem is it tends to lose power after awhile .. 15 or 20
minutes.
I've replaced the spark plug and fuel filter .. but I haven't had it
looked at by
real small engine repair place simply because it takes *weeks* to get
these
things looked at ! I's a headache getting it to a shop because it
needs
trailered.

I use to have a Sear 15HP it that thing hauled ass .. until I bent the
crank shaft
and ruined the engine.

This Murray is slow .. and even in 6th gear ... It's slow .. Then it
gets slower after 15 minutes !

Whats the possibility of replacing the engine with a new one , and
maybe even larger size ?

PS: The muffler kept falling off and in my 2 attempts at repairing
THAT
issue the mounting
holes are ruined and I run without a muffler too. It was running slow
before that happen however.
Now I have a SLOW and LOUD mower !

 
That's more a problem of gearing than power, I agree Murrays are slow,
I recently transferred the engine out of a worn out MTD to a Murray,
and in top gear a person could out run it without breaking a sweat, I
could catch dogs and cows with the same engine in the MTD (Which is
likely why it was worn out.) You do have an engine problem though RE:
15 min

Most of the engines have similar mounting schemes, drilling a few holes
in the frame wouldn't be a big deal, the pulley for the blades /
transmission would need to fit the shaft though. Even at that I've had
machine shops bore them out if too shallow or too narrow


You could drill out the holes and helicoil them.

Philosophical statement; you could probably pick up a used mower on
Craigslist for the price of a new engine that you would be happier with.

 
Eric in North TX wrote:


 Yeah ... buying again has crossed mu mind but my luck with used
(motorized)
    crap is exactly that .. used .. Crap !

 Are you sure your gas cap is vented? I had this happen on small push mower
but the tank was smaller than a tractors tank so it would take longer to
draw a vacuum on the larger tank until you start starving the engine for
fuel. Try running the engine the way it is and when it starts slowing down
at fifteen minute mark unscrew the gas cap enough to seeif that helps. If it
helps then you have a non venting gas cap, replace the cap with a proper
venting one. If that didn't do it I haven't a guess what more it could be.

I might be selling an 16hp Briggs come spring.

Rich