Transom ideas for ib/od

[Hofty]

Hey folks,

So u had a Volvo B20 motor in this boat. That motor has been bored to its max specification 0.004" over and can join longer be bored but requires sleeves.

I have decided to seek out a Mercuiser 3.0 or 4.3 with Alpha 1 drive. What sort of transom work is required to convert to a mercruiser engine and drive?

Thanks in advance. See pictures of the current keyhole. One is a mercruiser drive keyhole and the circular hole is my setup from Volvo Penta motor with AQ100 drive.

Thanks for your advice.

 

[todhunter]

You'll have to do some measuring - not sure if the old hole is in the right place / small enough to just cut the big hole over it. If it isn't, you'll need to do a transom replacement and cut a new keyhole for the Mercruiser running gear. You may want to make sure engine mounts don't need moving either.

 

[Hofty]

You'll have to do some measuring - not sure if the old hole is in the right place / small enough to just cut the big hole over it. If it isn't, you'll need to do a transom replacement and cut a new keyhole for the Mercruiser running gear. You may want to make sure engine mounts don't need moving either.

So I have sourced a 165hp Mercruiser motor. Alpha 1 gen 1 drive. The motor has 900 hours on it. I'm considering s rebuild and new exhaust manifold(s) & risers. See attached video of the motor.

So rebuilding the transom likely is my best bet?

 

[Scott Danforth]

900 motors is nothing on a maintained motor.

the AQ100 hole is tiny. you may get away with just opening it up to the mercruiser keyhole

 

[Hofty]

900 motors is nothing on a maintained motor.

the AQ100 hole is tiny. you may get away with just opening it up to the mercruiser keyhole

Scott,

You always chime in at the right time. I took your advice specifically on finding the Mercruiser engine and Alpha 1 drive. To be more specific. I have a actually sourced 2x engines & 2 legs. Either I salvage one for parts if needed of I resell one as a combo to recoup some costs.

So you think perhaps I can use that existing keyhole from the AQ100 hole? The transome seems solid and doesn't appear to have rot.

Check both videos of the motor(s) thoughts?

 

[Scott Danforth]

compression on both motors?

print out the early mercruiser MC keyhole and lay it over your transom and check

 

[Hofty]

Have not even picked up the motors yet. I'm picking them up next week. Will run a compression check on them at that time.

 

[Scott Danforth]

Have not even picked up the motors yet. I'm picking them up next week. Will run a compression check on them at that time.

suggest you get compression numbers before you buy them.

 

[Scott06]

Have not even picked up the motors yet. I'm picking them up next week. Will run a compression check on them at that time.

not to rain on your parade, regardless of condition you may want to reconsider getting either of these engines. In the videos you can see rounded cavitation plates on the drives. This means they are not alpha ones but he earlier MC1 drives with the lifting eye on upper. While these are a decent drive, the tilt/trim and some components may be obsolete. Neither these drives or 165 engines (also reliable) have been made since 1982. So if you are doing this to keep the boat would suggest you look for a 1991 and up alpha gen 2 drive setup so you don’t face parts nla down the road.