Can we talk about 4 stroke mercury’s from the early 2000’s?

[ShoestringMariner]

I bought a boat tonight. I knew the motor needed repair or replacement so I considered it as a part out motor as I have a few 2 strokes to run on it for this season.

But on the way home I started thinking about digging into it to see what’s wrong with it. I don’t know anything about these motors. What’s good compression on 4 strokes?

Before I do a comp test, anything I should check beside oil? Timing belt looks ok visually.
The model is 50elhpt 2001 or 02 were these good motors? I’d like to clean up my act and get away from 2strokes

Thanks

 

[QBhoy]

My personal view is that although at the time, is was a good effort and probably required, that the industry had to go down this road…but I also think that these early efforts just couldn’t compare to the time tested and trusted engines that came before…the 2 strokes.
The early 4 strokes were heavy beastly things and lacking any real punch. Just so lazy compared to the 2 stroke equivalent. The idea of a timing belt on a marine engine also doesn’t excite me much either.
But we’ll looked after, some of them seemed to be robust enough perhaps.
They weren’t for me at all though. The older 2 strokes now have a greater value than the early 4 strokes from that era.

But…fast forward a decade or two to the present….these new Mercury engines of the last few years…my goodness. They are in a different league altogether. They are managing to outperform an equivalent 2 stroke and in some cases…even manage to be lighter in weight. Look up the new Mercury 115. You’ll be astounded at what that thing can achieve.
Mercury are way ahead of anyone else right now. That’s a fact. Yamaha really need to catch up quick to compare or come close even.

 

[ShoestringMariner]

My personal view is that although at the time, is was a good effort and probably required, that the industry had to go down this road…but I also think that these early efforts just couldn’t compare to the time tested and trusted engines that came before…the 2 strokes.
The early 4 strokes were heavy beastly things and lacking any real punch. Just so lazy compared to the 2 stroke equivalent. The idea of a timing belt on a marine engine also doesn’t excite me much either.
But we’ll looked after, some of them seemed to be robust enough perhaps.
They weren’t for me at all though. The older 2 strokes now have a greater value than the early 4 strokes from that era.

But…fast forward a decade or two to the present….these new Mercury engines of the last few years…my goodness. They are in a different league altogether. They are managing to outperform an equivalent 2 stroke and in some cases…even manage to be lighter in weight. Look up the new Mercury 115. You’ll be astounded at what that thing can achieve.
Mercury are way ahead of anyone else right now. That’s a fact. Yamaha really need to catch up quick to compare or come close even.

Thanks for the background and insight on these.
When it comes to a full rebuild, I assume 2 stroke is most cost effective to rebuild?
(2Stroke = Less parts to replace and handle, less machining costs and easier set up/tuning?)

 

[Scott Danforth]

Compression about 150psi

 

[ShoestringMariner]

Compression about 150psi

Thanks Scott. Is that optimum or factory comp? What’s the low range of acceptable? Say 120?

 

[ShoestringMariner]

OK something inside the powerhead on this one.. I started doing a compression test And it turned over just slightly until it went clunk. Solid clunk.

My guess is a broken rod or bent valve.
Any thoughts on where I start looking? Should I pull the head??

 

[ShoestringMariner]

And a new mystery; the model number is 50elhpt but it is NOT A tiller. Does this make sense?