My MTD riding mower with a 17.5 Briggs and Stratton has been having a
hard time rolling over when I go to start it. When I turn the key the
starter will not roll over at first, it seems to struggle at first but
the it turns over. It's almost as if there is to much compression to
over come. The last two times I mowed my lawn after about 5 minutes
there is a noticeable loss of power and then the motor starts to sputter
and now has quit. I am thinking that it could be sticking valves or
perhaps crankcase ventilation. Any comments/input would be appreciated.
Thanks, CJ
I wish I had done that test with a neighbor's riding mower.
He had the same problem, starter would not turn it over,
even with a new battery and connecting the battery directly
to the starter with jumper cables to bypass the solenoid and
everything else. It would engage and try to turn it, but just
could not. I was convinced it had to be a bad starter.
He bought a new one and same thing.
He finally had Sears come out to fix it and they told him it
was the valve adjustment. Sounded bizarre to me, especially
since he as a small lawn, the mower wasn't that old,
maybe 5 -7 years and otherwise worked fine.
But apparently they rely on some sort
of compression release system to reduce the torque required.
When the valves get out of adjustment, apparently that must
affect the compression release system.
The fact that it spins with the plugs out suggests you have
a similar problem.
try putting jumper cables from a vehicle to the mowers battery.
if it still cranks poorly that will elminate a battery or charging
issue....
charging voltage with mower running should be around 13.8 at the
battery, any lower and the generator isnt charging properly
I would expect to see a voltage of at least 14 volts but not as high as
15 volts. The best way to check it is with an ammeter. Even cheap
multimeters will handle 10 amps DC. I doubt a riding mower charging
system is going to put out more than 10 amps DC. ^_^
TDD
When I was servicing a lot of residential generators, I would have to
adjust the valves on the engines after the things had been in for about
a year or after a prolonged power outage from a storm where the gensets
had been running for days. It wasn't all that difficult on the Generac
generators that had the B&S Vanguard V-twin. The last one I installed
had the Generac developed and manufactured big honkin' V-twin engine
that seems to be bulletproof. ^_^
TDD
On Jun 10, 9:09 pm, The Daring Dufas <the-daring-du...@stinky-
finger.net> wrote:
too loose.
I replaced the head on my neighbors riding mower last summer after it
swallowed the exhaust valve when the valve guide came loose
(supposedly common problem for that vintage - mid to late 90s). It
was a 14.5 BS OHV and I went through the exercise for adjusting the
valve clearance. He was ready to junk it, but I said that I could fix
it cheaply for him and I got the parts from Sears. Out of curiosity I
split the case and examined the part on the exhaust cam that does the
compression release at low RPM. My neighbor replaced the battery this
year, but it's still going strong.
If it's the B&S Vanguard, it's actually a pretty good engine if you keep
it serviced, especially changing the oil. I thought it was funny
that the Vanguard used the same oil filter as my old 2.2L Dodge K-car. ^_^
TDD
Well heck, it's a horizontal engine like the Vanguard in the older 8kw
Generac residential generators because the generator was belt driven and
sitting vertically next to the engine. The valves should be just as easy
to adjust. I think I have a piece of shim stock somewhere I cut to make
it simpler to set the valve clearance of which I don't remember the
value. Must be in some of those dead brain cells I lost along the way.
Now when I write horizontal, I'm referring to the plane the flywheel and
piston are in, the shaft is vertical. ^_^
TDD
The overhead valves are a heck of a lot easier to adjust than the old
valve in block designs. I've actually used a propane torch to heat up
the older valve in block engines to get them to run. ^_^
TDD
Had an oil change recently, and good quality brand name oil?
.
Christopher A. Young
Learn more about Jesus
www.lds.org
.
.
My MTD riding mower with a 17.5 Briggs and Stratton has been having a
hard time rolling over when I go to start it. When I turn the key the
starter will not roll over at first, it seems to struggle at first but
the it turns over. It's almost as if there is to much compression to
over come. The last two times I mowed my lawn after about 5 minutes
there is a noticeable loss of power and then the motor starts to sputter
and now has quit. I am thinking that it could be sticking valves or
perhaps crankcase ventilation. Any comments/input would be appreciated.
Thanks, CJ
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