Looking to repower 1976 Grady White

[demarko210]

So i am looking to put a newer motor on here after I get the cap and transom wrapped up (see my build in my signature). I previously had an inline 6 115 on here with the switch boxes. I still have the motor but I would like something more modern and more power if possible. The boat tags says no more than 150hp. I was looking to buy a pro xs 115 or 150 to mount on the back of here. Why is there a limit on HP recommendations? Can i go with a 200+ HP? I have put new plywood on the back. let me know thanks.

 

[dingbat]

What model Grady White?

As you can see from the calculations below transom strength has nothing to do with HP rating of a boat.

Grady’s are not speed boat.....150 is more than enough. 115 would be typical. 135 would give great performance


https://www.gpo.gov/fdsys/pkg/CFR-20...-sec183-53.xml

 

[demarko210]

dingbat

It is a grady white weekender. I am looking at a proxs 115-150hp. Thanks for the reading, I was just wondering if I could should I... The I6 did really great and is a simple to work on. On top end it pushed that old boat nice even though the foam was water logged and I was really scared to move with the rotten transom. I thought i ask before i spend $5-6k and could have gone up with more HP. I just fish and relax not looking to race.

 

[alldodge]

Being a 1976, I'm thinking this was before the motors where prop rated HP. So a 115 may have been 100 or less at the prop. If you get a newer motor (not 4 stroke) then a 115 would actually be a jump in power

 

[Chris1956]

Get a Merc V6 motor of 135HP or 150HP. They are great motors, with lots of low end power, compared with a 115HP inline motor, of any year. I would recommend you pick one mid-90s or newer, as they are a bit better than the earlier V6 motors.

 

[demarko210]

Chris1956

Thanks Chris we spoke a while back about my inline when I was having problems with it. Good to see you are still here. I been in the hull restoration forums for the last 2 years. I will take that recommendation of 135-150hp thanks.

AllDodge

Thanks Dodge

 

[Johnson110]

Where can you find a black max 135 mercury that is still a good motor ?

 

[Chris1956]

Gee, not sure what you mean.... the basic engine is still used today on the Optimax motors, no?

 

[Johnson110]

Yes but they used to make a carburetor version of 135hp black max, more basic than optimax no injectors etc, heard they are good motors but they are considered old now.

 

[flyingscott]

Yes but they used to make a carburetor version of 135hp black max, more basic than optimax no injectors etc, heard they are good motors but they are considered old now.

A 135 carb motor is cheap to fix! Optimax not so much when the major parts are priced well North of a $1000. With an optimax you are tied to the dealer they are well beyond repairing in your back yd. The 2.5 litre carb block from Mercury is probably one of the best V6s ever made of not the best.

 

[Johnson110]

I like that "2.5 litre mercury one of the best V6"

 

[jimmbo]

As mentioned the 135 or 150 V6s would be excellent choices, stump pulling power, good top end, and decent fuel economy too boot!

 

[demarko210]

I was considering PROXS over Optimax. I saw an PROXS a few years back with a 3 cyclinder pushing 115 hp. At the time I was like this engine would be much more efficient than the one I have at the same HP rating with 3 less cylinders. now the PROXS are v6 now.

 

[demarko210]

Also where do you look for boat engines? Is there a trusted place to look online? I hate wasting gas just riding, I like to know where I am going before I go at least. Thanks

 

[Johnson110]

Grady White is a good boat, what I would do is inspect and check out the boat carefully before you put a large engine on it being it is a 1976 boat. As far as finding a good engine I would check to see if you have any local marinas see if you can get a rebuilt engine also I would question the rebuilt you want new pistons and bored out if needed.

 

[demarko210]

johnson 110

Thanks. If you click on the signature in my footer. That link takes you to images of my boat restoration. I have put in new stringers and transom on this boat. I currently about to put in the floor as soon as the weather breaks so I can lay another layer of glass on the stringers. I suppose I can call the local marina instead of just riding out there to them. thanks

https://drive.google.com/open?id=0B95_CdtAK79BVGtiUzI1VWJwN00

 

[Johnson110]

Nice Job, I brought several years ago a Johnson 110 engine from a guy who rebuilds engines, he told me it was not worth putting old pistons back into block he used new pistons and did a nice job on the rebuild engine ran flawless, since than I sold boat and purchased a different one the guy has left and moved so I can not use him again. Like you I was considering getting V6 outboard 135 mercury but I do not want the optimax nice engine but to me too much can go wrong with it!

 

[demarko210]

johnson 110

I have a mercury 110 (2 banger) i took apart and put new piston rings and hone the cylinders cleaned the piston. I never got around to trying to start it. i had problems with the starter pulley after taking it apart 3 to 4 times i just left it alone. I will start it when the weather breaks. I bought it used as a trolling and get home motor in bad condition. I also bought it to get a feel of working out a smaller version of the inline 6 encase i decided to do a rebuild on it. I have both engines here in my back yard. I will take your advise and make sure there is at least new pistons installed and see if they had the block machined. I would prefer a carburetor motor just because anything else seems intimidating to try to work on myself. either way i will be purchasing a book on what ever motor i buy to do simple stuff like tune ups, oil change (if 4 stroke) etc.

my inline 6 i put stator, switch boxes, exhaust gasket, rebuild the carbs, trigger and more. I still have not figure if i got the timing correct but i am pretty sure i did. My problem with it now is when i put it in reverse on the dock it will cut off. I have a thread here about it. but everyone was telling me that its the carbs. I was following the manual to the letter. open carbs to 1.5 turns then put in gear, then adjust the carbs. that did not work in my case because the motor would shut down. I now realized that I may have to open my carsb maybe 2.0 or 2.5 turns to keep it running when i put it in gear. Then make the needed adjustments in forward gear to get rpm at 750. I like the motor and would keep it if i can test if i am correct. Ii would even rebuild it instead of buying a new one. that trade off is worth it to me. i just feel if i am going to spend the money just get something more fuel efficient and more power i will just have another motor to get use to because i do not trust shops anymore with my boat.

 

[demarko210]

Well i have not researched anything about the optimax. I was stuck on the proxs when i saw the 3 cyclinder 115 i think like 2003 i could be wrong. But if you can with a quick sum up if you know, whats the deal with optimax? my quick search says they are the same blocks just different reeves or piston rings....

 

[demarko210]

Also what is the difference between the blue labels motors and the red label?