mower engine repair question. help? photos too.

**ghettosled** · 08-12-2008, 04:35 AM

my buddy gave my this murry 11hp 38" tractor mower (briggs and stratton motor) because he was just going to dump it by the curb since it stopped working. i did the usual tests and it has fuel, spark and air. i also tried to use some starter spray to ensure it was getting enough fuel.

as it cranks, it sounds like its trying to fire, but cant get running. i then started to inspect the head and i notice a head bolt is missing, and two other bolts are just finger tight so i pull the head to check out the condition of the head gasket. could a failed head gasket cause the motor not to run? in my VERY limited engine knowledge, i thought it would still be able to crank over and run, just not very well. timing seems to be good as i rotated the motor by hand.

if installing a new head gasket should do the trick, aside from replacing the missing head bolt, do i need to replace all of the bolts? any other parts i should check out and/or replace while im tearing this apart? thanks in advance.

**Spaz** · 08-12-2008, 05:08 AM

a failed head gasket would only make it run "bad"... did you flush the fuel and change the fuel filter???

**ghettosled** · 08-12-2008, 06:12 AM

im planning on replacing the fuel line, filter and probably rebuilding the carbureator. my buddy said that before it died on him it was running really rough. then when he turned it off, he couldnt get it started again.

**Spaz** · 08-12-2008, 06:15 AM

Originally Posted by ghettosled

im planning on replacing the fuel line, filter and probably rebuilding the carbureator. my buddy said that before it died on him it was running really rough. then when he turned it off, he couldnt get it started again.

hmm... possible hydrolock??? i dunno...

**SteveCZ28** · 08-12-2008, 08:22 AM

it could get moisture in the cylinder when your buddy would park it over nite with a h/g the way it is, and make it a bitch to start. brigs and strattons are also little bitches to need the magnets cleaned on the flywheel too as the coil generates power thru them. take some 1500 grit sand paper to the magnets on the flywheel and give her a shot with the new h.g in it

**Blitzed** · 08-12-2008, 08:31 AM

Originally Posted by SteveCZ28

it could get moisture in the cylinder when your buddy would park it over nite with a h/g the way it is, and make it a bitch to start. brigs and strattons are also little bitches to need the magnets cleaned on the flywheel too as the coil generates power thru them. take some 1500 grit sand paper to the magnets on the flywheel and give her a shot with the new h.g in it

I second this, makes sure the stator magnets are clean

**Spaz** · 08-12-2008, 08:36 AM

Originally Posted by Spaz

hmm... possible hydrolock??? i dunno...

Originally Posted by SteveCZ28

it could get moisture in the cylinder when your buddy would park it over nite with a h/g the way it is, and make it a bitch to start. brigs and strattons are also little bitches to need the magnets cleaned on the flywheel too as the coil generates power thru them. take some 1500 grit sand paper to the magnets on the flywheel and give her a shot with the new h.g in it

beat ya to it...

**SteveCZ28** · 08-12-2008, 08:40 AM

Originally Posted by Spaz

beat ya to it...

yeah i was trying to explain why it would hydro lock, or ran shitty for him. i knew what we were talking about, haha

**Spaz** · 08-12-2008, 08:45 AM

Originally Posted by SteveCZ28

yeah i was trying to explain why it would hydro lock, or ran shitty for him. i knew what we were talking about, haha

i had this happen to me while i was ridding my quad...

didn't have enough speed to hydroplane across the river... sank 7/8 of the way across...

**SteveCZ28** · 08-12-2008, 08:46 AM

ouch! not fun

**4get gto** · 08-12-2008, 05:41 PM

Blown head gasket right at the exhaust valve. Put a new head gasket on and torque it right and I bet ya it fires..........

**310stanger** · 08-12-2008, 05:55 PM

As already stated, freakin head gasket is blown dude lol Severe compression loss. It absolutely could have a no start issue with a blown headgasket. The only way it would hydrolock is if A. Somehow it ingested water directly into the cyl, or b. raw gas dumped directly into cyl with a spark plug not firing. and then suddenly firing.

Clean off the combustion chamber, the cyl deck, and the head and put a new head gasket on. Tighten the head down and give it a whirl. You could clean the magneto if you want to but you already said you verified it has spark. I'd bet on it that the fucker runs with a new headgasket.

**ghettosled** · 08-13-2008, 09:29 AM

im back from the local mower parts and repair shop with a new gasket in hand and a replacement bolt. great tip about cleaning the magnets - will do. i hope by tonight she will be purring like a kitten once again. im totally stoked about the thought of having a tractor mower for the cost of $14 in parts and a couple hours of my time. though if it does run, next purchase is a new battery. it will get annoying to jump start it every time.