Merc valve cover gaskets--exhaust man

[backwater dawg]

I have a pair of 1988 Merc 260's- pretty close together and need to change the valve cover gaskets--I'm getting conflicting advise concerning the clearence of the exhaust manifolds--can I get the valve covers off or do I need to remove or just loosen the manifolds a little bit- I'm getting different opinions on this--also-if I am able to just loosen the manifolds-what do I do about the gaskets-I was told they make a slide in one??? Any help would be great before I start braking bolts for nothing--It's a 20 year old boat with over 2400 hours and (thank god) no engine work-Thanks-Steve

PS-I live and boat on the intersection of the Mississippi and St Croix rivers--the Mississippi is open in some spots but the St Croix is very deep and slow moving---most of the river is covered with 3-4 feet of ice---but spring is coming

 

[Coors]

Re: Merc valve cover gaskets--exhaust man

Just cut notches, and make your own slide-ins.

 

[Don S]

Re: Merc valve cover gaskets--exhaust man

Uhhhh, how are you planning on cleaning the old gaskets off? They are usually stuck pretty good.

 

[Bondo]

Re: Merc valve cover gaskets--exhaust man

can I get the valve covers off or do I need to remove or just loosen the manifolds a little bit

Ayuh,......... Maybe.....

It's probably 80/ 20 odds that the covers will clear the manifold,....
Sometimes they can be finangled around,+ come off......

As for trying to Slip in new exhaust Gaskets when you Just Loosen the manifolds,......

That's a 100% chance of Failure......

If you don't Pull the manifold,...
You can't remove the old gasket, nor can you Clean the gasket surfaces....

If you Loosen the manifolds,..... They Have to come All the way Off....

Dagnabit Don,....... You're Quicker'n My Finger again..........................

 

[Coors]

Re: Merc valve cover gaskets--exhaust man

Evidently, some aren't up to full painful contortions...

 

[Don S]

Re: Merc valve cover gaskets--exhaust man

Dagnabit Don,....... You're Quicker'n My Finger again..........................

Not really, you just got too wordy

 

[backwater dawg]

Re: Merc valve cover gaskets--exhaust man

Sooooo--what I'm hearing is to go ahead and try to pull the valve covers off without loosening the manifolds--and if they won't come off--pull the manifolds compleatly off and do it right--next ? is--I'm concerned that as I pull the manifolds off I'll break bolts-again-1988 model-never been off-one thing I heard is to run the engines and get it hot--then crack the bolts-let cool and R&R the covers and manifolds??? Will that work or does anyone have a better way to do it---I hate to drill and tap--especialy in the cramped space--thank Steve

 

[Bondo]

Re: Merc valve cover gaskets--exhaust man

Ayuh,.....

Your Plan will Probably work, Steve......

Personally,.... I Never-sieze the manifold bolts,+ sparkplug threads.....
And,.....
I'd probably just pull the head if I broke off the manifold bolts,+ didn't have a Clear Shot at it....
But,.....
Like I said above,....
You might get Lucky,+ the tin covers can be wiggled out......

Btw,.... 1 more Tip.....
Sometimes it'll get hung up on a rocker arm,.... Bumping the motor over might lower that rocker....

Good Luck,+ come on back to let Us know how it goes.......

 

[TilliamWe]

Re: Merc valve cover gaskets--exhaust man

Btw,.... 1 more Tip.....
Sometimes it'll get hung up on a rocker arm,.... Bumping the motor over might lower that rocker...........

Especially if you have the center bolt valve covers. On my 1997 engine, I ended up rotating the starboard valve cover so that the top surface was parallel to the ground then lifted straight up on it. It cleared the exhaust, then got stuck on the rocker arms. I then turned it back to it's original angle and them shimmied it forward and aft and it slipped right off.