4.3 Manifolds/Risers

jkimball

Petty Officer 1st Class
Joined
May 14, 2013
Messages
220
So I'm trying to get some opinions on manifolds/risers for a '97 4.3 LX.

I got my boat in August (first sterndrive after several Outboards) and the PO said that the manifolds & risers were done a couple years ago, but he also used to boat in the Gulf in Pensacola. So the boat has seen some salt.

The current risers & manifolds have some rust on the outside of them, and I haven't pulled them yet to inspect internally. Mostly because I haven't had any cooling issues as of yet. It stays a constant 170* per the gauge and the risers are always cool enough to the touch to lay a hand on them.

But, I know that one day the inevitable will come and I'll have to replace them. That said, I have found a guy locally that has (4) GLM risers for sale for $85 ea. new in the box - which seems like a pretty good deal. But I cannot find ANY good reviews on GLM... so should I steer clear?

Also, when it comes to manifolds it seems near impossible to find true OEM merc parts (which my boat currently has btw - risers & manifolds) and even iboats has Sierra & H20.
I've heard varying reports on Sierra and really NOTHING on H20.
So I'm looking for some recommendations
 

Rick Stephens

Admiral
Joined
Aug 13, 2013
Messages
6,118
I don't think Merc actually made the 'OEM' ones but subs it out to one of the after market manufacturers. I have GLM elbows and manies, I did a reasonably simple surfacing on the gasket surface between the two and they aren't bad at all. Some forum members seem to have had bad results from them, not me, so far, knock on wood.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,468
Ayuh,.... I've got GLM manifolds, but not the risers,.....

When I got 'em, the center ring of the gasket surfaces was 'bout .030" lower than the outer gasket surface ring,....

I got 'em cut down, Flat, at my local machine shop, No problems since,....

They leaked like a sieve before the resurafce though,...

I'm a sweetwater boater, 'n many years later, they're still just fine,....
 

jkimball

Petty Officer 1st Class
Joined
May 14, 2013
Messages
220
Thanks Guys. Any input or opinion of the H20 manifolds sold here on iboats?
 
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