Mercruiser 7.4 Replacement/Upgrade
09-25-2021 | 07:46 AM
#11
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Joined: May 2012
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From: Midwest & T-Rock
ya, my mind doesn't think cruiser, good point
09-25-2021 | 08:20 AM
#12
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Joined: Apr 2006
Posts: 10,041
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From: Toledo Oh
i'm in similar situation to you i have a 1999 sea ray 260 sundancer that i just repowered with a used 7.4l "performance tuned" carb motor. finally got numerous issues sorted out with the drive, bravoitis, bad carb, bad fuel pump, bad sea pump etc. seemed like she was running great. took her out and ran good for a few hours than on the way home something went boom. blew out the ceramic part of the spark plug. now have low compression on 3 cylinders so i'm not in as bad of shape as you seem to be. Trying to figure out best upgrades to make if this motor can be rebuilt is making my head spin.
As for your situatino, a lot of people go to the 6.2/383 stroker and are very happy with that as a replacement, it has similar power to what you had before and less weight and will give you more room in the engine bay too. Of course, they are not cheap. If you plan to keep this boat for the long haul and are happy with it, it's worth it. You could also definately consider stepping down a bit in power and going with a 5.7 but i know nobody wants to feel like they are going backwards but that should still be a solid power plant for that boat. Its hard to come by 7.4l blocks and when you do they aren't cheap but there shouldn't be any reason why you can't just get a rebuilt block from somewhere and swap all your parts over to it.
those BRAND SPANKING NEW 6.2s look sweet though. if money is no object that route gets you 3 year warranty on the motor and could be worth the spend.
As for your situatino, a lot of people go to the 6.2/383 stroker and are very happy with that as a replacement, it has similar power to what you had before and less weight and will give you more room in the engine bay too. Of course, they are not cheap. If you plan to keep this boat for the long haul and are happy with it, it's worth it. You could also definately consider stepping down a bit in power and going with a 5.7 but i know nobody wants to feel like they are going backwards but that should still be a solid power plant for that boat. Its hard to come by 7.4l blocks and when you do they aren't cheap but there shouldn't be any reason why you can't just get a rebuilt block from somewhere and swap all your parts over to it.
those BRAND SPANKING NEW 6.2s look sweet though. if money is no object that route gets you 3 year warranty on the motor and could be worth the spend.
Champion plugs???
09-25-2021 | 09:56 PM
#13
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Joined: Jul 2019
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i'm in similar situation to you i have a 1999 sea ray 260 sundancer that i just repowered with a used 7.4l "performance tuned" carb motor. finally got numerous issues sorted out with the drive, bravoitis, bad carb, bad fuel pump, bad sea pump etc. seemed like she was running great. took her out and ran good for a few hours than on the way home something went boom. blew out the ceramic part of the spark plug. now have low compression on 3 cylinders so i'm not in as bad of shape as you seem to be. Trying to figure out best upgrades to make if this motor can be rebuilt is making my head spin.
As for your situatino, a lot of people go to the 6.2/383 stroker and are very happy with that as a replacement, it has similar power to what you had before and less weight and will give you more room in the engine bay too. Of course, they are not cheap. If you plan to keep this boat for the long haul and are happy with it, it's worth it. You could also definately consider stepping down a bit in power and going with a 5.7 but i know nobody wants to feel like they are going backwards but that should still be a solid power plant for that boat. Its hard to come by 7.4l blocks and when you do they aren't cheap but there shouldn't be any reason why you can't just get a rebuilt block from somewhere and swap all your parts over to it.
those BRAND SPANKING NEW 6.2s look sweet though. if money is no object that route gets you 3 year warranty on the motor and could be worth the spend.
As for your situatino, a lot of people go to the 6.2/383 stroker and are very happy with that as a replacement, it has similar power to what you had before and less weight and will give you more room in the engine bay too. Of course, they are not cheap. If you plan to keep this boat for the long haul and are happy with it, it's worth it. You could also definately consider stepping down a bit in power and going with a 5.7 but i know nobody wants to feel like they are going backwards but that should still be a solid power plant for that boat. Its hard to come by 7.4l blocks and when you do they aren't cheap but there shouldn't be any reason why you can't just get a rebuilt block from somewhere and swap all your parts over to it.
those BRAND SPANKING NEW 6.2s look sweet though. if money is no object that route gets you 3 year warranty on the motor and could be worth the spend.
On the other hand I've heard great things about the Mercruiser 8.1 & 8.2 non cats. Not as fuel efficient but I wonder if that would be better performance wise and just a safer engine. I've had different issues within the last 3 years so Im leaning towards a new and reliable engine with a warranty.
Thanks,
Scott
09-26-2021 | 06:15 AM
#14
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Joined: May 2009
Posts: 632
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From: Indiana
1 - Of all the people I have ever talked to that owned a boat, not one of them ever said “I wish it had a smaller engine, it just has too much power”
2 - “Fuel economy”
Buying fuel is the cheapest part of boat ownership.
2 - “Fuel economy”
Buying fuel is the cheapest part of boat ownership.
09-26-2021 | 07:19 AM
#15
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Posts: 920
Likes: 600
From: Central Louisiana
7.4 or 502 and save yourself a lot of headache. Torque is your friend with that boat. A fresh 7.4 or 502 will get just as good of fuel mileage as all of the above give or take a mpg.lol Good luck in your search...
09-26-2021 | 09:47 AM
#16
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Thanks,
Scott
09-26-2021 | 12:50 PM
#18
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Joined: Jul 2015
Posts: 1,202
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From: Atlantic Southeast
383 Stroker MPI 6.3L Mercruiser is your go to small block engine for the older 7.4L engines.. 350 HP and 390 Ft lbs of torque @3800 rpm. And you'll have a 10%+ gas savings.
Go to Mercurymarine.com to find a dealer in your area that is a qualified re-power center.
Go to Mercurymarine.com to find a dealer in your area that is a qualified re-power center.
09-26-2021 | 01:09 PM
#19
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Joined: Nov 2009
Posts: 4,198
Likes: 500
From: KY
Not an exact comparison but pretty close
My 1995 Rinker 232 4800 lb with 300hp 7.4 carb, drive B1 and it has no problem pulling up 3 solemn skiers or much anything else
Been a few newer Rinker 232's with 5.7 and B3 drive over the years at my marina. Have talked to them over the years and every one of them say the same thing about getting up on plane. I'm assuming they were all 5.7 and not a 6.2 but they were EFI or MPI
My 1995 Rinker 232 4800 lb with 300hp 7.4 carb, drive B1 and it has no problem pulling up 3 solemn skiers or much anything else
Been a few newer Rinker 232's with 5.7 and B3 drive over the years at my marina. Have talked to them over the years and every one of them say the same thing about getting up on plane. I'm assuming they were all 5.7 and not a 6.2 but they were EFI or MPI
