Carver Owners Forum

I have 2 350 Mercruiser MPI in My 2001 350 mariner.
One of the motors has a lifter tick I just cant eliminate.
I am going to put a new set of lifters in it (cause I don't know which one is ticking)
Are a set a Chevy lifters for the same year 350 the same?
Or did Mercruiser use something different?

Those should be roller lifters, not sure about if same as regular Gm, maybe, but I don't know who made the cams for them..........be sure it is not an injector/ exhaust leak/ sticky valve first, would be my advice unless you have eliminated those already.

Does the engine run fine and did the noise start right after spring start up ?

They SHOULD be the same as any GM Vortech 350. As mentioned, it's a roller cam/ roller lifter engine.
Somewhere around 2001/2002 GM changed to the LS1 engine, those lifters will not work in your motor, so you want to make sure you get the proper ones.
Before all that, are you sure it's a lifter, not and exhaust leak or something else?
Hate to see you tear down the top end and have the same issue.

Its the starboard engine. Yes i starts right up and runs fine. But the ticking noise which sounds like a lifter tick to me, is there constantly. Haven't taken anything apart yet altho I am going to replace the exhaust manifolds shortly as well so figured a good time to replace the lifters. I don't think this engine has injectors as it has what looks like a carb but throttle body on it.

Darkhorse, MPI means Multi Port Injection so it is most definitely injected. The lifters are about $150 each so I’d take the time to figure which one is ticking. Usually with a roller lifter if it’s giving a really loud tick it’s most likely the roller collapsed and it’s grinding the cam away like a hyperactive kid on the class pencil sharpener.

https://www.wholesalemarine.com/mercury ... t1-lifter/

Also, have you tried to do a cleaner in there? I wouldn't leave it in there long, or do a lot of heavy-load running with it, but a few cycles and an oil change might make the issue go away. It won't repair a bad part but if it's just some debris or crud causing the problem it'd be a much easier solution than a teardown and the accompanying risks of causing other issues.

There’s a product called Sea Foam out that a mechanic I know raved about. You might want to look into that. Have you heard of this product Viper?

Ya I've heard of Sea Foam, it's been around for a while and is a popular product. In certain circumstances they have their place but I'm not a big fan of most additives, I've always found most of them to be a whole lot of marketing hype and not actually provide meaningful results. I suppose they are a cheap alternative worth trying first on the chance that a symptom is just on the edge but I wouldn't put all my faith in them.