whats the Tallest gear for merc,s OB

[afr]

i have a stock v6 case i want the tallest gear possible even if i have to loose reverse
1.87 is no where near enoph gear for me im not sure a 173 is even enoph

[appsyscons]

i have a stock v6 case i want the tallest gear possible even if i have to loose reverse
1.87 is no where near enoph gear for me im not sure a 173 is even enoph

Scott,

The sportmaster lower for my 300SX comes "stock" from Mercury Racing, in 1.75 and 1.62 and in either LH or RH rotation.

[afr]

cool deal i asume the sprtmaster gears will fit a stock case
do you have the part numbers for the 1.62 rh and what about the small prop shaft
im pretty sure you have that new prop shaft for the big hub
some of the guys tell me i wont be able to turn it but they forget this is a hydroplane not a regular tunnel or v
but the only way to know forsure if there right is to try it

[appsyscons]

cool deal i asume the sprtmaster gears will fit a stock case
do you have the part numbers for the 1.62 rh and what about the small prop shaft
im pretty sure you have that new prop shaft for the big hub
some of the guys tell me i wont be able to turn it but they forget this is a hydroplane not a regular tunnel or v
but the only way to know forsure if there right is to try it

I think this is what you are looking for

8 is the forward/pinion gear set
18 is the reverse/pinion gear set

I am not sure which one is 1.75 and which one is 1.62

[appsyscons]

I had the info on the gear ratio, I just found it:

8 43-878087A6 --GEAR SET, Forward/Pinion (1.62:1) msrp:$479.60
8 43-859321T04 --GEAR SET, Forward/Pinion (1.75:1)

18 43-848880T1 --GEAR, Reverse (1.62:1) msrp:$486.53
18 43-848881A1 --GEAR, Reverse (1.75:1)

[afr]

yes thats very helpfull i truley think more gear is the answer im looking for
the 1.62 and prop combo with the rpms im after puts me up to 125mph on the prop caculator without winging the motor way up 8600 is about as much rpm as i will let it go
with my 2.1 im guessing till next time out case the tack was not working i may be in the 6000 rpm range with about 3to4 inches of throttle left to go 10.000 rpm witha 2.1 seems to be wasting alot of power

thanks again ill dig into this again on monday @ the shop if you get time stop by
cool i was posting at the same time you were
ill call it in and see if i can put that on the small propshaft

[OneBadInjun]

i have a stock v6 case i want the tallest gear possible even if i have to loose reverse
1.87 is no where near enoph gear for me im not sure a 173 is even enoph

What Mercury V-6 O/B engine exactly, are we talking about? Cause the 3.0 litre gearcases don't work on a 2.4/2.5/200 crank.

[njthumper]

Those 1:73 and 1:62 gearsets are for the 3.0, 3.2 lowers. I don't think they will fit the 2.4, 2.5 lowers which were available in 2:00 and 1:87.

[afr]

i have the 2.5 i didnt check yet but im told there are 162 and 173 gears that will fit my case but no one think i can turn it but me but without riding in the boat there just guessing

[Bradz]

If you have a hydroplane boat you really should be looking at using a Speedmaster lower unit like the Champ boats. The setups there will give you the big numbers for top speed. Go to ScreamandFly.com for some better race outboards advise.

[afr]

If you have a hydroplane boat you really should be looking at using a Speedmaster lower unit like the Champ boats. The setups there will give you the big numbers for top speed. Go to ScreamandFly.com for some better race outboards advise.

yes i have to agree if i can get that done ill have to re up the prop inventory etc
and i would need a rh ssm so i dont have to spin the motor the other way to much work for just a river runner

[OneBadInjun]

If you have an older 2.5, all you need is a CLE gearcase, not a SpeedMaster. The CLE's had the low water pickups to allow a higher installed height, plus retain full gearshifting. CLE stands for cresent leading edge. The standard CLE ratio is 1.87:1 and is all you need on that boat. FYI, all the guts from a standard 2.5 gearcase, work perfectly, as is, in a CLE housing. Have fun.

[afr]

i had a cle 187 on here before but i didnt have the power i have or the set up and design changes i have now
i got the nose down good and the tail popped but as it is now i got a stock 2to1 with a cone all the prop calculation shows 95 at best i know theres a lot more in it
i might be able to test it this sunday and see where it ends up i dont think one or two times up to 10.000 rpm might be ok just for a quicky
ill let you know what i get

[OneBadInjun]

You have a 2 to 1 gearcase now? What is this motor? A 2.5 200 horse? Or a 2.5 150 horse, or what? If its a 200, definately loose the 2 to 1 gearcase. This is your problem.

[afr]

its a ported 2.5 175 pose to be about 245 hp but its never been on a dyno
yea the 2.1 has to go
i got a freind looking for some gears