49M977-1036-G5 Shredding crankcase gaskets

[KE4AVB]

Just wondering if anyone had a problem with the 49M series Briggs.

This is the second time that this engine has shredded the crankcase gasket. I have gone in it yet this time but from what I see already it has done the same thing again. Last time the gasket looked like expanded steel. It was torque to the latest spec at the time. And I it is now 325 in/lbs. It is like the crankcase cover is moving back and forth running the gasket in two.

I already got a spare gasket and new bolts in stock. It just going take me some time to get it off and back on due heat index hitting 110F the last week and looking to stay that way for a while.

[bgsengine]

I'd probably want to clean and inspect crankcase gasket surfaces for shiny spots , and also probably do a dry fit and see if it wiggles around on locating pins, before putting new gasket & bolts in (might also check bolt holes, to be sure bolts are not bottoming out or hydro locking, thus fooling your torque wrench?)

[KE4AVB]

I'd probably want to clean and inspect crankcase gasket surfaces for shiny spots , and also probably do a dry fit and see if it wiggles around on locating pins, before putting new gasket & bolts in (might also check bolt holes, to be sure bolts are not bottoming out or hydro locking, thus fooling your torque wrench?)

Actually the areas were rubbed grey last time. Just too damn hot right now to work on the engine. 95F with heat index hitting 109F according the weather service; sure seems a lot hotter. I got Mac chainsaw tore down on the outdoor work bench and I can't stand long in the sun to get it back together. Waiting for 6 pm to come then I try getting together.

I just going have break down get my myself one those open air carports to work under.

[hanz63]

IMO you'll never get it to keep a gasket. Me, I'd do a dry fit w/o a gasket. If it has couple hundred hours on it, it will probably be fine. Right stuff for sealant, prep the threads and lock it down hard. Or replace it.

[38racing]

IMO you'll never get it to keep a gasket. Me, I'd do a dry fit w/o a gasket. If it has couple hundred hours on it, it will probably be fine. Right stuff for sealant, prep the threads and lock it down hard. Or replace it.

Will crank end play go too low with no gasket?

[Arkie]

IMO you'll never get it to keep a gasket. Me, I'd do a dry fit w/o a gasket. If it has couple hundred hours on it, it will probably be fine. Right stuff for sealant, prep the threads and lock it down hard. Or replace it.

Will crank end play go too low with no gasket?[/quote]

I have put some of the 31 and 33 series Briggs together without a gasket using Yamaha Bond 4.

I' check the crankcase end play with no gasket and if within specs I just use the yamaha Bond.
I use a wire brush on a battery operated drill and clean the gasket surface area really good then also use a cleaner. I let the Yamaha Bond set for about 12-24 hours before adding oil.
I've also used Yamaha bond on each side of a gasket with good results.
I've had to go back few on some enngines times if I just used a sealant on the non-sump side of the block, the oil eventually seeping between the paper and the non-sealant sump side when the block and oil got hot. I do not like go backs. Yamaha Bond is pricy but I store un-used tubes in a fridge and it last forever.
It bonds better than RTV. I've used it on chansaw blocks (2 cycles and no gasket with good results.

Cannot imagine the sump moving enough to destroy a gasket if the locating pins are in place.
I would at least try to clean out the sump thread holes, chase the threads with a bottom tap and mic theeir depth and the length of the bolts to make sur all are getting torqued W?0 bottoming.
I've felt your pain is why I started using Yamaha Bond 4, but I already stocked the Yamaha Bond 4 for 2 cycle chainsaw blocks.

10-4 on the trying to do shade tree mechanic work lately, temp in 100's and no wind blowing.

[hanz63]

So I have done this a handful of times. The first was a be back for one I had done a short time before. I mean I chase the threads, clean the threads, used the fancy gasket set w/bolts, prep, torque it perfect and it shook itself apart. That one I know is still running and its been years. My rule is this: If sumps bolts work loose, it gets a new engine or I try the sealant. I lock them down hard too. And I don't warranty them in either case.

Remember the early 90s when the first Intek 28's shook themselves apart? Briggs use to warranty a new shorty or engine on these for a reason. I've gone through and tried the poor man's knurl approach to help hold the gasket. Tried Gasgacinch. The gasket would just tear in layers.

If you haven't noticed, I have a general dislike for engine internal guts work.

[Arkie]

You say:

If you haven't noticed, I have a general dislike for engine internal guts work.

AMEN: especially when it's go backs.

hanz63
On the 90's Briggs model 28's was the vibs mainly due to something bad about the counter balance or ?????????

[Arkie]

KE$AVB:

Check for a PM

[hanz63]

I don't recall if it was a counterbalance issue or what. It seems over the years, failure is the safest bet when I've attempted to reseal something that has come loose.