If you're referring to their earlier model sprint engine or smaller
3.5/4hp they're not too bad as long as you don't run them to hard.
Anything past about 87 is pure crap. Especially their Quantum or
larger OHV junk.
Aluminum used in high stress parts such as valves and piston arms
etc...
B&S is also good about changing tolerances in mid production to ensure
aftermarket parts jobbers suffer, not to mention how it can make the
home repair owner's life hell.
I could go on and on...
I have a huge pile of B&S motors behind my shop(I do small engine
repair).
Most suffered catastrophic engine failure do to cheap material and
shoddy craftsmanship, some right out of the box.
As for interchangability.... IF you can get a part to cross you're
lucky.
I've had experiences where internal parts from one model wouldn't fit
an exact model of the following year or series.(Mostly piston arms/
crankshaft tolerances.)
B&S likes to vary the coil sizes as well. Techumseh's generally use
one size coil.
B&S likes to use a plethora of different length and style of control
cables as well, both throttle and safety/cutoff cables.(AND charge and
arm and a leg for them.)
B&S also uses the worst carbuerators I've ever seen as well as the
most ill concieved govenor system ever applied to small
engines.(plastic carbs on their small engines that once they wear out
that's it, just toss and replace. Even the more expensive engines use
crappy Walbro carbs.)
After just hours of use most B&S engines suffer uneven engine idle as
the govenor system can't adjust for engine runout.
I have some Techumseh engines that have been going for years and
hundreds of hours.( Steel alloy pistons and cast irons sleeves)
You're lucky to get the rated hours out of a B&S.(FYI the small 3.5/4
hp mower engines that Briggs makes are generally rated at 30-40 hrs of
use. I have managed to get as much as 100 out of some of the older
models but only after tweaking the govenors down and keeping fresh oil
iin them at all times.)
As for Briggs not needing service... I do a steady business on small
engine repair and most of the dead lawn equipment that come into my
shop have B&S motors.(Burned coils in the first year, engine
explosions due to poor craftsmanship/tolerances etc...)
I mostly swap them for a tecumseh engine and have happy customers
thereafter.
It could be said that at one time Briggs did make a quality engine,
however that's simpl not true anymore.(I DO have some vintage Briggs
from the early 60's and as late as the late 70's that are very fine
engines and put Brigg's later offerings to shame both in reliability
and power.)


Dang have they really gone that far downhill? I've had nothing but excellent
performance out of B&S engines, I particularly like the 80's-early 90's I/C
flatheads with the cast iron bore, maybe I've just been lucky but I've just
never had anything major go wrong with any of them and the carburetors have
been some of the easiest and most dependable I've ever dealt with. I've had
too limited experience with the OHV stuff, encountered them a few times on
pressure washers I've borrowed (and they worked well but were also fairly
new) but I've never had to work on them.

I've had exactly the opposite experience with Tecumseh, though I was never
surprised because last I checked (about 10 years ago) they were always about
$100 cheaper than a comparable size B&S. I've had several of them throw
rods, ignition go wonky, carburetors that wouldn't stay in tune and would
clog up every time they sat a few months, hard starting, rough idle, and it
always seemed like they were unnessesarily hard to take apart for simple
stuff (head bolts holding the cowling on?!). They were the one brand I swore
off ever buying.

Guess I better hoard the few old (mostly late 70's-early 80's) B&S engines I
have.