I changed my outdrive !!!

[pscott66]

Hi All
K so I had to swap out my outdrive this year. I have a 97 Mariah 18' bow rider. It has a 4.3l lx Gen II engine and an Alpha 1 Gen 2 drive. Last year's drive was a 1.63 ratio, with a 17" pitch prop. The hole shot was amazing and top speed was around 60k. Although I could over Rev it if I wasn't careful
This year the new (used) drive is a 1.84. I used the same 17" prop cause that's what I have ... took it out and it ran like a bag of poo. All my research says that the 1.84 drive should be a better ratio for the V-6 engine, and a 17 pitch prop is pretty light I think. So what the he'll !!!

 

[pscott66]

 

[Scott Danforth]

you sure on the ratio? there is a 1.81:1 and a 1.94:1

Mercruiser Alpha 1 Gen 2 (1991 & Newer)​

Engine	HP	Liters/CID	Cylinders	Gear Ratio	Tooth Count	Year
3 Liter	130	3.0/181	4	2.0	24-24	1998-2005
3 Liter	130	3.0/181	4	1.94	20-24	1991-2005
4.3 Liter	175	4.3/262	6	1.81	17-19	1991-2005
5.0 Liter	230	5.0/305	8	1.61	24-24	1991-2005
5.7 Liter	260	5.7/350	8	1.47	20-22	1991-2005

also, not sure of any Alpha 1 Gen 2 drives with a 1.84:1 ratio. a gen 1 yes, behind the 3.7 and early 4.3's however not an A1G2

Mercruiser Alpha 1 (1984 – 1990 Models)​

Engine	HP	Liters/CID	Cylinders	Gear Ratio	Tooth Count	Year
2.5 Liter	120	2.5/153	4	1.98	20-24	1984-1990
3 Liter	130	3.0/181	4	1.98	20-24	1984-1990
165	165	3.7/224	4	1.84	17-19	1984-1990
175	175	4.3/262	6	1.84	17-19	1984-1990
180, 190, 470	180	3.7/224	4	1.84	17-19	1984-1990

 

[pscott66]

184 is a little older 1.84 became 1.81 ... 1.84 is 95 and older

 

[pscott66]

And that 4.3l is different... only 175 hp ... mine is 4.3lxgen+ 220hp.

 

[Scott Danforth]

You trying to convince yourself? You swaped out the better A1G2 for an A1G1 or MC1.

 

[Bondo]

... took it out and it ran like a bag of poo.

Ayuh,..... As in How,..??
It should be revin' to the moon, 'n goin' nowhere,......
Yer gonna need a bigger prop to match the drive ratio,.....



Benchmark: 68,000th post

 

[briangcc]

Ok...stupid question alert...

Mine is the 180HP variant of your 4.3 v6 and it came with the 1.6x ratio A1G2 drive swinging a 4 blade 18P prop. IF you got amazing holeshot and top end, why, oh why, did you change the outdrive to a ratio different from what you had already and were happy with?

Seems to me a slight tweak on the prop if you were hitting the rev limiter would have gotten ya further...and more than likely cheaper....

 

[Scott06]

Hi All
K so I had to swap out my outdrive this year. I have a 97 Mariah 18' bow rider. It has a 4.3l lx Gen II engine and an Alpha 1 Gen 2 drive. Last year's drive was a 1.63 ratio, with a 17" pitch prop. The hole shot was amazing and top speed was around 60k. Although I could over Rev it if I wasn't careful
This year the new (used) drive is a 1.84. I used the same 17" prop cause that's what I have ... took it out and it ran like a bag of poo. All my research says that the 1.84 drive should be a better ratio for the V-6 engine, and a 17 pitch prop is pretty light I think. So what the he'll !!!

Get a 19” pitch prop and you will be the same as you were with the taller drive ratio

I run a 1.82 drive with a 5.0 after swapping a 4.3 out and went from 19” pitch to 21” pitch and it works fine

 

[pscott66]

Ok...stupid question alert...

Mine is the 180HP variant of your 4.3 v6 and it came with the 1.6x ratio A1G2 drive swinging a 4 blade 18P prop. IF you got amazing holeshot and top end, why, oh why, did you change the outdrive to a ratio different from what you had already and were happy with?

Seems to me a slight tweak on the prop if you were hitting the rev limiter would have gotten ya further...and more than likely cheaper....

At the end of last season it blew the oil hose to the drive and water must have got into the lower gear case, and it froze .. I tried to get it rebuilt but no dice .. now I'm thinking swap out the top end of the old and bottom end of the new.

 

[pscott66]

Ok...stupid question alert...

Mine is the 180HP variant of your 4.3 v6 and it came with the 1.6x ratio A1G2 drive swinging a 4 blade 18P prop. IF you got amazing holeshot and top end, why, oh why, did you change the outdrive to a ratio different from what you had already and were happy with?

Seems to me a slight tweak on the prop if you were hitting the rev limiter would have gotten ya further...and more than likely cheaper....

Oh I don't drive like that .. we use the boat for wakeboarding and top speed for that is around 20 mph. but the hole shot is everything ... 19 is the correct prop. But I dropped it a notch to find 1st. gear

 

[QBhoy]

And that 4.3l is different... only 175 hp ... mine is 4.3lxgen+ 220hp.

Not sure about your idea of 220hp. As far as I know, only the 4.3 mpi and a recent reman from quicksilver would be 220hp.

 

[QBhoy]

Hi. Yeah you’ll need more than a 17” with that ratio. At least a 19, more likely a 21