7.4L Mercruiser Advice

Locke

Petty Officer 3rd Class
Joined
Oct 23, 2006
Messages
84
I'm looking at a 1988 Sea Ray Pachanga that has 2 7.4l engines with Alpha 1 drives, I'm not very familiar with this combination and need a little help. Both engines appear to be original and have around 925 hours each. I'm going out for a test ride this weekend and then doing a compression and fluids check if I'm still interested. How many hours can I expect to get out of these motors typically assumming decent mainenance and what should I look for when inspecting. The boat looks to be in average shape with decent maintenance, all the systems I've checked so far work.

Thanks

Locke
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: 7.4L Mercruiser Advice

Mercruiser used the Alpha drives on the 454's from 86 thru 88 but the drives really won't stand that much HP if run hard. In late 88 Merc came out with the Bravo drive that could handle the HP and torque of the big block engines.
As long as you take it easy, the engines should last around 3 to 5000 hours with proper care.
 

bronxlatetour

Petty Officer 3rd Class
Joined
Jun 16, 2006
Messages
77
Re: 7.4L Mercruiser Advice

I'm by now means a mechanic so the info I'm telling you isn''t proffesional. I have a 1990 Sea Ray with the 7.4 Bravo. It only has aprox. 360 hours on it but it runs like new. One other thing, when I was looking for boats last year I had found a 1988 with the 7.4 alpha combo. I was "strongly" advised against getting it because the 7.4's shredded the alpha's. I was told that by a few boat places. Once again, take it for what it's worth. Hopefully some more knowledgable people on here can shed some light on the subject for you.
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: 7.4L Mercruiser Advice

Twenty some years ago drive showers didn't exist.
Synthetic gear lube wasn't being used in the sterndrive.
The Alpha's used in a big block application were failing because the drive came out of the water when the hull is on plane, no cooling. Lube overheated, broke down, drive failed.
I know two individuals with this power package, both are original owners. Both are still running today. Both are adult owned and operated, single engine applications.
Install drive showers.
Use synthetic gear lube.
Don't try to cross Lake Michigan at Wide Open Throttle.
 

Locke

Petty Officer 3rd Class
Joined
Oct 23, 2006
Messages
84
Re: 7.4L Mercruiser Advice

Thanks guys. The outdrives have drive showers on them so they must have been available or retrofit, either way they're there so that's a good thing. So the 900+ hours aren't a problem?
 

xtraham

Lieutenant
Joined
Jul 20, 2006
Messages
1,425
Re: 7.4L Mercruiser Advice

Locke: listen to Don S, and the engine's and gears will will be handed down from generation to generation,

BTW welcome to iboats
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,095
Re: 7.4L Mercruiser Advice

Ayuh,........

The 454 is a Great motor,.........
And,...
The Alpha series is a Good Drive,..........
But,........
Together,... They make a Lousy Combination..........

Very Fragile.....
 

xtraham

Lieutenant
Joined
Jul 20, 2006
Messages
1,425
Re: 7.4L Mercruiser Advice

Ayuh................
Bondo........are you heavey handed? 8)
kidding.............
 

Bondo

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Apr 17, 2002
Messages
71,095
Re: 7.4L Mercruiser Advice

xtraham said:
Ayuh................
Bondo........are you heavey handed? 8)
kidding.............

As in having a Doctorate in Common Sense,+ telling it Exactly as I see it,..??..??.......

Or because I Overly use the punctuation,+ Capital Letters,...??...??......

I Guess I'm Guilty of Both....................................d:)
 
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