not sure exactly why this happened. motor was full of oil. was running about 4000 rpms when i heard a distinct noise. i thought i shot a plug out.

not really a mechanical guru, but do have a few questions. do i need a new head? how expensive do u thnk this is gonna be? any reasons to y this would happen?

Holy crap that looks bad. Maybe drop the exhaust valve. What mods are you running?
And at least a new head.

Aft mine dropped the valve I heard alot of noise at first and then it would turn over no problem. With no noise

Hard to tell from the pic, did it pull the rocker arm stud boss out of the head?

how could it have dropped the valve you can see it there in the picture

That ain't bad few $$ and back and running!!

When I say drop a valve I mean just the head of the valve. That is what mine did and from the top you would never know the difference. I briggs valves are 2 piece.

Looks like the exhaust valve adjuster is backed way out. Not sure if thats normal? Possible its a bad casting like you mentioned. Sure seems like if it was an issue with the valve or the rocker arm it would have bent the push rod before breaking the head. But I can't see much of the pushrod either. Please let us know what you find out. Hope it isn't to costly for you.

the exhaust valve adjuster is backed out. but...it is tight! its not loose. i had to break it loose to turn it. so...i dont think that it backed loose and let go of the push rod and thats what caused this. im still not sure what caused this. i havent pulled the head yet and looked at the top of the piston. but i talked to hoyt this morning. he said he has seen this a few time, and most prob its from either

a) running the motor with a lil water in the fuel
b) the big cam i have put too much gas, flooded the motor and made a weak spot and it just decided to give at that point
c) its a bad casting from briggs and stratton


i dont really know what happened, but as long as the top of the piston looks alright he said everything below it is fine. he hooked me up with a new head, i should have it at the end of the week...so we shall see. he did mention that now they are starting to run a different cam which is a lil smaller and not so harsh. so if it happens again ill go that route.

thats all i know at this point in time. when i take the head off and look at the piston ill keep u all updated, just hopin its alright.

dam man that sucks sorry to here that .

I don't see the crack ... where's the crack ?

two better pics i took that day, didnt realize that the cracks were hard to see.

Head is shot.. Didn't throw the valve spring so I'm guessing the valve in still in place and didn't hurt the cyl.. New complete head is $175 list.. You might be able to locate a used one someplace.. If the heads we're worked then you'll need to match up the new one..

Threads in the stock heads are sketchy at best.. I've got one I had to put a helicoil into.. Thinking about putting one in all holes next time around..

I saw that crack. Hell, I'm still seeing that crack.

I wouldn't be surprised if u dropped an exhaust valve.... seen it happen already and da valve stem stayed in place as well as da rest of da valve train. Just da end of valve came off and destroyed da head along with da piston.

Ditto on da suck stock threads in da head boss.... got a heli-coil in mine too.

Da reason da valve adjusters are backed way out is because da heads are prolly decked and he's runnin stock length push rods which will work, but don't leave much room for adjustment... just a guess, don't know exactly what he's runnin.

Best case scenario you gotta replace a head... so you might as well pull da muther off and see how far da damage went.

Good luck.

anyone know what the helicoils are that rail and stumpy are talking about?

ok I know what your talking about now.
Thanks ben.

thank u all for the input, and concearns. its goin to hoyt in the am tommorow, so we shall see. ill let u boys kno when i hear something

What's up with the torx and allen head valve lash adjuster? Never seen that on a factory rocker arm before.

yea i suppose it was. would that really be a big deal though? anyways i dropped it off to hoyt today..hes gonna fix it and do some more work..so the wait begins

forgot to update, got the rig back a while back and it was just the cracked head. were thinking bad casting. everything else looked fine.

good deal Jessie, glad you got her fixed up.

The heads were worked up by hoyt originally, when he re assembled he probably just grabbed an adjuster out of a box full and used it.