27’ SEA NAUTIQUE 1984

Hello and glad to be aboard! Just inherited this 27 footer and could use some help with a few things. I'm sure more things than I think. I contacted Correct Craft but their archives are not very well organized as I was told. They are going to see what they can dig up but suggested I contact Correct Craft Fan. So here i am. It seems most of you are with ski boats but maybe there are a few cruiser owners among you. I'm told by Correct Craft that she is rare and only about 18 were built. My girl is fitted with twin 351 PCMs with 1 1/2 -1 gears. Original sales brochure states she runs out at 42MPH but she is no where near that. tops out at 3200 RPM. motors were new 3 years ago. Props are 1-1/4" 16x17 3 bld bronze and are new and clean. Nobody has been able to tell me what the props should be, even Correct Craft.
Any help for the turtle boat? Thanks

how much clearence to the hull and prop blades do you have?

sounds like it is proped way to high, you need a smaller dia and/or smaller pitch too. the RPMS should be in the 4500 range.

Some one on here has a san juan don't think it's as big as yours but your's sounds real cool please add it to the diary's section.

that's true Tim I did assume that everything is timed right, the ignition system is working properly and all of the components are in good working order.

But if the tune-up is correct then what else is left? The guy didn't state that it ran bad just low on rpm and speed and wasn't sure if the props where right and that sounds like that guy knows what he's doing a little bit otherwise he would have been asking about tune-up specs and not props.

GottaSki wrote: Could also have been over-cammed from an overzealos rebuild?

possible but I wouldn't think so, never seen anybody really cam up a cruiser that big. Also not sure that the rpm has much effect on the secondary's aren't they opened based on vaccum or lack there of and that is what opens them up?

well then as a test would it be possible to open the secondaries manually while underway?

at a minimum I guess would be to verify that they (secondaries) are actually not opening.

So now the questions seems to be what is the state of tune and are the carbs working porperly? is the time right on both, are they both pulling equally or is there an issue with one causing the other to over work?

But again it sounds like the boat is running fine just maybe over proped based on the post.

Well besides the hull to prop clearance. it would be help full to know how much gap is between the strut and backside of the prop.

At some point maybe someone lengthen the prop shafts to create more clearance to run the larger props.

So I would say that it should need about 1.5"-2" between the hull and prop blade and from a 1"-.5" from the strut to the props hub.

I'm actually looking forward to seeing some pictures as the brouchure only shows an artist's sketch and it will be cool to see the real deal.

Where's that gray hair old man that always ask for pictures when you need him

Eric, You see larger boats than most of us. What's your take on twin 351's swinging 16X17's through a 1.5 to 1 ?

Thanks for all the input and suggestions. I know this much. Both engines were new not rebuilds, Trans are 1.5 to 1, both motors run like clocks ( swiss clocks at that), both run up tp 3200 and thats it. I believe secondaries are operational. Only thing that I replaced was flame arrestors. I installed 8" d x 4" H. arrestors and only because the breather tube nipples had come off. The boat is at my shore home, so when I go there this weekend I will take measurements with regards to clearances and set backs. I will also take pictures of her and post when I get back. I did notice that at an idle, 650 RPMs she moves fast, like she's cutting deep into the water. Michigan wheel told me by the part numbers on the wheels that they are 1 1/4.shafts with 16x17. My son looked yesterday when we were there and said he saw 16x16 on the inboard end of the hub. I know they were new props as my friend owned and gave me the boat. Unfortunetly he would never know if the boat ran good or bad as long as it started and ran. He had a stroke and a heart transplant so I can't have a meaningfull conversation with him either. If anybody has any other thoughts on the subject I will check what ever I can this weekend. I can't run it yet as I pulled all four manifolds and risers in the fall when I winterized her. The engines had original block drains that were female hex plugs. They were not coming out and it was already 34 degrees outside so I drilled out the center of the plugs and figured I would worry about replacing them in spring, hence the reason I dropped the manifolds. Better than worring about a cracked block. Hey, Thanks again for all the input, I really appreciate it. Roger