complete Alpha one Gen one retrofit into older boat.

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
I have a 1971 Starcraft Offshore V18 that really just needed a new gimbal housing but is a basic 2.5L early gen 1 Mercruiser drive. I bought a complete running 1986 Four Winns with Alpha Gen 1 3.0L. to use as much as I can.
I want to eliminate the questionable 1970 wiring ( has a dead short somewhere, some of it is a mess ) so I'd like to use the 1986 harness BUT, the Four Winns is 16' vs the 18' offshore so I think I may need a longer harness. But what one? 8 pin, 9 pin? I also want to get a brand new controller as the one on the Four winns one is broken. the throttle can be forced into gear without pulling the trigger. It just slips past the stop. I'm thinking 4 winns gauges too but I'll keep the SC switches
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,756
Shouldn't be much issue. Could totally rewire with 10 pin (only has 9 pins actually) harness. There still sold but are pricey
 

Scott06

Vice Admiral
Joined
Apr 20, 2014
Messages
5,671
As AD outlined they make longer harnesses both in Merc and universal fit. I think looking at a place like Michigan Motorz and on ebay you would find what you need.

You should put eyes on your existing donor harness, even though the boat is shorter the harness may be long enough for your new boat. On my 21 ft Sea Ray the harness is folded over itself and zip tied a couple times to shorten it. You may get lucky and have enough length already
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,561
they also make extension harnesses.
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
I have not torn it apart enough to see if it’s folded or wrapped up. Gotta pull the shifter to get the side panel off. On the star craft there is several feet coiled up. An extension harness would be the ticket if needed. The donor harness is literally pristine. So all these end in a small molex connector on the dash. Side?
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
Any clue what control I need? Want a trailer switch on the control if it exists
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,756
Search Mercruiser throttle control, any will work.
Most new ones have the trailer button as part of the control. Its no biggy if it doesn't, just install a toggle or rocker momentary switch elsewhere to work
 

76SeaRay

Lieutenant Junior Grade
Joined
Aug 24, 2017
Messages
1,047
Be careful with buying harnesses. The pins in the connector are sometimes different sizes and different configuration. So, if you are replacing everything, make sure the engine harness pins match the ignition harness pins in size and configuration. I ran into this in replacing everything on my boat. I ended up buying more than one harness to get the right one. EBay pictures typically don't give a clear enough shot of the pins. I also found that even though it may have 9 pins, it may only have 8 wires. My ignition harness has 9 pins and 9 wires. My engine harness has 9 pins and 8 wires. The difference is that the engine harness is missing the alarm wire but otherwise matches the other wires. One more thing, older harnesses have large gauge wires in some spots if you have an Ammeter on your dash (likely for an old boat). Newer harnesses have smaller wires since you typically use a voltmeter.
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
Be careful with buying harnesses. The pins in the connector are sometimes different sizes and different configuration. So, if you are replacing everything, make sure the engine harness pins match the ignition harness pins in size and configuration. I ran into this in replacing everything on my boat. I ended up buying more than one harness to get the right one. EBay pictures typically don't give a clear enough shot of the pins. I also found that even though it may have 9 pins, it may only have 8 wires. My ignition harness has 9 pins and 9 wires. My engine harness has 9 pins and 8 wires. The difference is that the engine harness is missing the alarm wire but otherwise matches the other wires. One more thing, older harnesses have large gauge wires in some spots if you have an Ammeter on your dash (likely for an old boat). Newer harnesses have smaller wires since you typically use a voltmeter.
I’m replacing the gauges with the ones from the donor boat. So I won’t have to worry about mixing new and old
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
Search Mercruiser throttle control, any will work.
Most new ones have the trailer button as part of the control. Its no biggy if it doesn't, just install a toggle or rocker momentary switch elsewhere to work
Oh okay. I was getting hung up with ones that said mercruiser in listing but then “ Mercury/mariner outboards” in the description
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,526
Search Mercruiser throttle control, any will work.
Most new ones have the trailer button as part of the control. Its no biggy if it doesn't, just install a toggle or rocker momentary switch elsewhere to work
Ayuh,.... I like to put one at the transom, reachable from the ground, without crawlin' into the boat,....
Great for servicin',.....

It's pretty easy to put a trim/ tilt switch anywhere on the hull, that's handy to ya,.....
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
Sound like a plan. Put one near the engine cover. Anyone know if the old style mercruiser gauge panels accept standard gauges? Like a 3 3/4” speedo and 2” gauges?
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,756
Don't know, but if you need to go bigger, clamp a piece of plywood behind the hole. Then use hole saw and drill larger hole. Start in reverse drilling so it doesn't bight and move quick
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
Don't know, but if you need to go bigger, clamp a piece of plywood behind the hole. Then use hole saw and drill larger hole. Start in reverse drilling so it doesn't bight and move quick
Good idea. I’m thinking to use the panel to kinda bring the retro into a little modern. Plus the gauge set from the 4 winns is 5 gauge same as the old
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
How much does a 3.0 weigh? I plan on using my girlfriends fathers 80hp loader tractor with clamp on pallet forks to extend the reach. I know the loader has the height to do it
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,756
About 300 to 350, the tractor will have no issue so long as the hydraulics on the tractor are ok. A round bail of hay comes in around 1200
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
Oh okay I was worried about my clamp on pallet forks but at 500 lbs they won’t have an issue. It’s actually a fairly new tractor. I just need the forks to extend the reach
 

Scott06

Vice Admiral
Joined
Apr 20, 2014
Messages
5,671
Oh okay I was worried about my clamp on pallet forks but at 500 lbs they won’t have an issue. It’s actually a fairly new tractor. I just need the forks to extend the reach
Check the overall height typical issue is by the time it is hanging down from what ever with a foot or two of chain , you still need to get over the gunnel…
 

matt167

Captain
Joined
Sep 27, 2012
Messages
3,702
My plan is to put the trailer on 4.80x8 tires for the swap which will drop it about 6” and get that height to clear the gunnel. I also think hooking the lift chains together with a heavy duty ratchet strap will allow me to pull them together and get a couple inches
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,561
My plan is to put the trailer on 4.80x8 tires for the swap which will drop it about 6” and get that height to clear the gunnel. I also think hooking the lift chains together with a heavy duty ratchet strap will allow me to pull them together and get a couple inches
skip the tires all together. put two 2x4's on the ground and run the hubs directly on the 2x4's

jack the front of the trailer up until the aft end of the trailer is touching the ground
 
Top