Would this be blasphemous?
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Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=46878
Printed Date: March-10-2025 at 3:00am
Topic: Would this be blasphemous?
Posted By: smac76
Subject: Would this be blasphemous?
Date Posted: October-06-2018 at 12:13am
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I'm interested in what the feedback would be regarding replacing my original 351 with a new, EFI powerplant when the time comes to repower/rebuild. I have 1750 hrs on my 76 SN and it still runs good, but like all things old, it always seems to need constant tinkering. This is probably due to the infrequent use (I only get up to the lake about every 3 weeks) rather than simply mechanical issues, but I cant help but think that a modern powerplant would maybe eliminate those issues. I have a pontoon boat up there also, with a 3 year old outboard that is turnkey and go week after week. I've considered selling the boat and just buying a newer one, but man, do I love this boat. ------------- It's 5 o'clock somewhere... |
Replies:
Posted By: PLBC
Date Posted: October-06-2018 at 9:44am
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It is your boat. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=5164&sort=&pagenum=1" rel="nofollow - 99 |
Posted By: SNobsessed
Date Posted: October-06-2018 at 10:22am
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You could refresh your engine with new, reliable, components for a lot less than buying a different engine. Also, good luck finding someone to diagnose a weird problem when you have transplant. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: Hollywood
Date Posted: October-06-2018 at 10:40am
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Maybe fix the problem(s)? Plenty of reliable 70s boats on here. At the Buckethead race this year a handful of boats were re powered with modern EFI engines and several did not run right. |
Posted By: 8122pbrainard
Date Posted: October-06-2018 at 10:41am
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Scott, I totally agree with Chris.
Tell us more about your problems. For years, I would travel between home and my second home on the lake with sometimes gaps of weeks and never had problems with my 54, 64 or my 77. You said: " like all things old,"  ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
SNobsessed wrote:Posted By: Gary S
Date Posted: October-06-2018 at 11:16am
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Bunch of naysayers. You looking to get a brand new engine? Who is going to do the engine install? What would be the budget? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: smac76
Date Posted: October-07-2018 at 10:08pm
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As far as the problems, it's never really anything major. I spent some time when I first bought the boat and went through the whole thing- new cap, rotor, plugs, wires, bilge pump, water pump, exhaust tubes, battery,etc.- and the boat really ran great except for the fact it would constantly like to idle high. Adjusting the idle screw didn't really help much. It would either idle around 900RPM or stall out. I figured it was just a characteristic of the boat and went on. The carb has since been rebuilt and that fixed the hard start when hot, but not the idle. Life goes on. This summer, I really never got to put much time into it. At first it was an idle problem- well, I guess it's been the same idling problem in one form or another- and in between the family saying "well, lets just take the pontoon" and everything else that comes with kids and their lives, I never really took the time to sort through what the problem may be. Maybe this will be the winter when I can track that problem down. Thing is, the boat always runs great sitting on shore. It's not til it's in the water sitting idle for weeks at a time that It gives me fits. I guess I was just thinking out loud about the eventual repower. It seems that most owners crave the originality and authenticity of the boat, and feel it would be a shame to alter a basically original, unmolested, classic that's in pretty decent shape. Much akin to putting a new EFI V8 in a 67 mustang. And while it may be nice to have a new, modern, EFI motor for the ease of maintenance and reliability, that carb'ed 351 does sound bad-ASS! I'll have to give it more thought. ------------- It's 5 o'clock somewhere... |
Posted By: Gary S
Date Posted: October-07-2018 at 10:56pm
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They are going to sound the same and you can always put the original engine back in it. There would not be a market for aftermarket FI systems if people wern't putting them in their 67 Mustangs. Have you ever thought where you would get a FI engine? A used take out or new? What is your budget ? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: TRBenj
Date Posted: October-08-2018 at 9:43am
This is incorrect. I would echo HW’s suggestion before proceeding. |
Posted By: Smithfamily
Date Posted: October-08-2018 at 10:32am
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I would rebuild when the time comes. KISS Theory ------------- Js |
Posted By: JoeinNY
Date Posted: October-08-2018 at 10:43am
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No it's not Blasphemous, but yes something is wrong with your boat that is probably much cheaper to fix than it would be to replace with a new one. I have a 67 wildcat that is all over my tween and young teen nieces and nephews social media accounts this summer- they just turn the key and always seemed to make it back. Other than having to pump the gas first thing in the morning it runs just like the fuel injected pontoon boat they learned on. Sure i had to deal with 50 year old leaky hoses and gaskets once or twice but it always runs great. You may have a vacuum leak, or someone has opened your secondaries up at idle so much that your idle circuit isnt able to work, or your card rebuild was not awesome, or your timing aint quite right - also possible your rings or valves are just a bit leaky... Either way your engine should idle way lower than you want it too if working close to correctly... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1477 - 1983 Ski Nautique 2001 1967 Mustang 302 "Decoy" http://www.youtube.com/watch?v=cO5MkcBXBBs - Holeshot Video |
Posted By: stepper459
Date Posted: October-08-2018 at 11:29am
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I didn't buy it new, but I managed to get an EFI engine for my old Supra to replace the old 351. However, the old engine went into a boat now owned by my father-in-law, and he's been using it for 11 years, so I can offer you a direct comparison. The EFI engine sounded the same if not better, going through the same exhaust; it was also a 351 but just a more powerful variant (the GT-40). It started every time but takes more revolutions to fire. It ran perfectly in spring, fall, hot summer days, and everything in between. This was nice because I used the boat well into the cold months. I also appreciated the extra power, (310 vs 240) because it was a big, heavy 21' boat. With regular tune-ups, the boat ran perfectly for 11 years. DISCLAIMER: I believe I got a deal on the engine because it had been overheated at some point. It had a knock at cold startup that would get better when warm. Eventually I tore it down and had a machine shop rebuild it - bored out the cylinders .020, put in new pistons, rings, connecting rods, bearings, that kind of stuff. Never did it let me down, but I should mention that rebuild haha. The old carbureted engine in that same time period has also run perfectly with regular tune-ups. It's had a fuel leak that was easily solved, it needed a new thermostat last year, and we've replaced the cheesy EI conversion kit in the distributor once, because the old one was literally held together with scotch tape (long story). It needs an extra pump of the throttle at cold start, and otherwise is basically a bump of the key to get going again once it's warm. I had a '72 Ford pickup with a 302 that was literally the lightest touch of the key, it was so satisfying to start that thing. This engine is close to that, but not quite. With the help of the knowledgeable people here, you should be able to get your old engine running perfectly. Maybe it's old enough (in terms of hours) that it needs a good bit of attention more than a tune-up, but that's still far less money than a new engine. Maybe a rebuild with a new electronic distributor? I don't think that would bother too many purists. Points are great, I have them in my truck. But they do require more tinkering. An EFI crate motor would be a sweet upgrade, but you also have to look at whether it would require rebuilding your doghouse / engine cover. In the Supra it was a split cover, so I was able to just rebuild the bottom half to be 4" taller. |
Posted By: Gary S
Date Posted: October-08-2018 at 12:15pm
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That's why I'm asking the questions I'm asking. Just trying to see if the original poster is serious or just dreaming. To get into a new bobtail FI engine will start at roughly 10k. Then who is going to do the work? Then there is the EPA question to deal with too. Find a used engine? Not exactly easy either,some of the same applies. How do you get the engine, who's doing the work, who determines the engine is good before you start the work. And then figure the costs involved. Then weigh that against say just throwing that old carb out and buying new,installing a DUI distributor and doing some basic trouble shooting as to why it does not idle down etc. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: phatsat67
Date Posted: October-08-2018 at 12:19pm
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It sounds like a vacuum leak. Someone needs to bust out a gauge and start doing some testing. If you aren't capable you need to find someone locally who is well versed in carburetor engine diagnostics (doesn't matter if it's a boat or car guy). That is getting fairly hard to find these days but most marina guys are just as bad at EFI as they are at Carbs so it doesn't really matter either way. If you are up for a little project this winter and want to add some jewelry to your tool box there are plenty of guys (already commenting in your thread) that can walk you through the diagnostics of your system if you are even mechanical in the slightest. |
Posted By: KENO
Date Posted: October-08-2018 at 2:32pm
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It seems like you went through all this vacuum leak, gasket replacement stuff about a year ago and in your words it was running great. Then winter showed up and then spring rolled around and it was not so good again. I don't think I've ever seen anything mentioning your distributor condition (like the flyweights and springs) or where your timing is at idle and also at higher speeds. That old saying along the lines of "when you think it's the fuel system, maybe you should look at the ignition system" might just be a big help here  Like Zach said a little time and diagnosis will get you through this issue. |
Posted By: Fl Inboards
Date Posted: October-08-2018 at 3:40pm
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The nice thing about re-power is three years from now every known part on the package will be available. I have a customer here in town we did a 79 SN with an Excalibur and zero off.. The guy runs it salt water too!!Skis great as it is stripped down to nothing more than two seats and motor box, ------------- Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise. 1993 Shamrock "fat" 20. 2008 Nautique 196 5.0 |
Posted By: Gary S
Date Posted: October-08-2018 at 4:14pm
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10 for just the bobtail Jody ? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: smac76
Date Posted: October-08-2018 at 11:26pm
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Wow, thats a lot of good info from you guys out there. Thanks. I'm a bit of a purist myself, so my first instinct is to try to keep the boat as original as possible. I was really just curious as to the feasibility of a modern powerplant upgrade. I spent 2 years restoring a '74 Harley Ironhead that I love riding and that always needs a little tinkering, too. Like I mentioned before, I think that I'll take this winter to go through anything I haven't touched yet, and touch on the things I already have, and see where we are in the spring. Thanks again for all the feedback. ------------- It's 5 o'clock somewhere... |