242 525sc swap
 

I have a 242 project I'm going to be putting a 525sc into , does anyone know if the mercruiser 9 prong plug is compatible with 525sc plug ? I'm sure I'm not the first to do this are there any other things that may hold up completion ? Going to start this as soon as it warms up , I will post pics and progress as it comes together should be a fun ride ! Any input will be appreciated thanks .

pretty sure 9 will plug into 10, but obviously 10 wont plug into 9, meaning boat harness 10, engine 9

Got it motor has 10 boat has 9 what's my best course of action here ?

Assume its an LS? Please let us know the progress very interested. Thanks.

Yes LS , just need to figure out what to do about the mercruiser plug ?

New boat side harness from mercury, under $200

Red you don't have a part number do ya ?

http://bpi.ebasicpower.com/pc/MAR6199-02-06/ALL6I

Looks like 80 bucks

What should I do change the plug on the boat or can I just change the one on the motor ?

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This is the connection I have in the boat

Matjluk, The link I posted is for the engine. This would allow you to connect to the plug already in the boat. Not sure off the top of my head what the 10th pin was for, but you may just have to make an external connection for it if it is needed.

10th pin is for the alarm wire, the 9 pin harness had a seperate wire that went around the cannon plug. I'd change the boat harness so no matter what you put in for power from here on out you're good

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This is the motor plug , I guess I could call a distributor and ask them for advice . Anybody have a part number do they not make an adaptor plug ?

Rewiring the boat for 10 pin should be pretty simple guessing the wiring diagrams are correct right ? Or is this going to be a pain in the ass , my only concern is when I go to remove the old wiring I take something out I shouldn't , am I over thinking this ?

Yes you are. The wiring is very easy and can be done in a few hours.
Purple wire switched ignition
Yellow with red start
Lt blue oil press
Tan water temp
Gray tach
Black ground
Red power from breaker
Tan w blue alarm.
Brown w white trim sender
If you snake the new harness in and swap 1 wire at a time off the gauges and ign switch its not hard
Where in mass are you?

Your probably right . As soon as the weather breaks gonna tear into it , I'm out of town a lot so I need to make the most of weekends and have all the right parts ready . Thanks I'm sure I will have more questions , I'm in agawam

Ill find a part number for you and some pics

Awsome

This great I live in west side I am sure we will see you on the river, good to see another Formula out there.

Masi , I'm on the river a bit I keep a boat there being how its so close. I like old saybrook better but then you kinda need some other boats with you in case of breakdown , I think I read one of your posts about bolster seats being redone ? You ever do that and how did they come out ? I've had upholstery done in the past and seems like no one can do factory jobs no matter what you pay . I got 2 formulas I'm always taking engines out upgrading and rebuilding . Ever have any questions or need a tool just ask have just about everything . - Matt

Thanks,Matt we`ll keep tabs on your project can`t wait to see how she`ll run. The seats are at the upholster in Lawrence,ma I got his name from another board member an his work looks very good, should have them soon.


mark

Part number 84 - 812475a20. Can anyone confirm this part number as being the harness I need for this project ??

Well motor is in boat , tight squeeze had to take half the accessories off and the all the pullies but its in there! [ATTACH=CONFIG]523419[/ATTACH]
Upholstery being done will post more pics as it goes .

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http://m.youtube.com/watch?v=5n3QVcRKcgs This is my little brother , he's scared of the motor and I was videoing so this cracks me up plus nothing better than working on boats in April clearly he had been drinking otherwise he would have stood to the side and given it som dam gas lol!

Yes home made engine stand 4x4's, 2x4's, wheels 30 bucks use everytime a motor is out !
Between the motor out !
Also farmers so no such thing as not doing it yourself ! To spec of course

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Even gel coat

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After

I love the video, he stands right directly behind the wet exhaust!!! How about some engine pics and definitely some performance data once you get it out.....

Hey great job on the swim platform is that all gel or paint? That's a great vid, can't wait to here how the 242 runs with that engine.

Gel

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I got a lot of wiring to do !!

Update ! Boat runs need to install outdrive and find shift parts for the bracket , install bunch of other things interior , oil reservoir for out drive clean up the wiring. Hopefully in a week will have it on the water ! Then propping only have a 23p 4 blade revolution to start with , will see what that does !

Can't wait,to,hear the results.

Oh it sounds nasty !! Lol

I had to remove all the accessories to get my engine out of my 242LS too. It looks more roomy than it is going in and out. My 242SS had no problem pulling out with everything in place. What is with that??? Stroked the engine for the LS but have not finished the heads yet to dyno. Excited here to see how yours performs. Boosting is a great way to get power on the water. I went with more stroke but don't know what the power is yet.

Definitely keep us posted with the project.

Took it out quick today for the first time , right off the bat was a blast ! With crappy prop was cruiseing at 40 about half throttle ! The power felt great and the throttle response . After about 30 mins cruiseing looked in the bilge and noticed a little slick power steering fluid leaking somewhere haven't located the leak yet , next weekend !
Aqua force I have an ls and ss working on the ss sucks as far as the motor goes had to put a starter couple years ago an nearly blew a nut trying to put the manifold back on ugh thought about selling that day , but there is so much room in the cockpit which is good !

The power sounds like a great thing. I am stroking a 496 for my LS and I will be around the same power level, I can't wait.

Yes I really like all the room in the SS too but I am partial to my LS. The engine is so boxed in that working on the SS is better done pulling the engine than getting a hernia. Hard to have my cake and eat it too between the LS and SS so I got the 357 to solve that problem. LOL

Well I tried a 25p 3 blade mirage today and I don't think the boat liked it seemed like It would barely get over 42 mph 3/4 tank of gas but really ? Guess I'm gonna try a 24p bravo1 and 23p mirage ! Thing makes a $hit load if noise just not seeing the numbers

I would try a out of the box 23 mirage plus and have it tweaked after testing if need be. That prop worked best for my old 242 with a 500 hp 509. You should be able to crack 70 with your set up