gear ratio for the sterndrive

[gezy]

i seen a bit in the last post on this,


so what will this be?.0f446668.alpha one gen2,thats all i can see on it.

[gezy]

well thats got you .

flat out 40 mph best i did this year.so thinking about the gears.

its like it needs to go up a few.we did that prop thing on the web site
pich 23 the size of the boat and so on .came back with that s/steel
prop on it is good for 60+ .and with all the props 21p,23p,19p.i run that
3000rpm it will just stay out of the hole.under very slow bow up in the air.

to get it out of the hole i need to give it a handfull like flat out 4500-5000rpm at this time up she comes and out.then i will pull the rpm back to 4400-4600 to run at 30mphwith 23 pitch .to get to 4o i had to rev the nuts of it.and thats no good for the engine.

maybe its setup for pulling skiers and stuff?.

and with the 23p. i got that size to over prop it and then work back.but it will still rev out with that on over wot.i cant keep getting bigger props for can i.

[seapuppy]

Gezy..what is your WOT rpm's???...and what engine do you have???...that will dictate what the wot is....fou
r instance...my 2455 I used to own topped out at 4600rpm....the book said between 4200-4800rpm....I hit at wot 42mph.......on my present 2700....wot is the rev limiter at 5280rpm due too it being an mpi engine....top speed is about 45mph....we cruise at about 4k rpm at 30 mph....at 3600rpm we're right at about stall speed on the water which is about 22mph....I can probably get it to stall at about 19...but that's with the tabs full down...
try this....put your tabs all the way down..drive trim down...hit the throttle .....you should get on plane at about 20 mph and then back the throttle back as you come up to stay at about 4k rpm....then start backing the tabs and drive up...it's kind of like juggling...but it does work........try that....

[gezy]

engine 5.7 vortec.4 pot q,jet carb.see what i mean your faster at 4000 than mine with yours.

gears in the leg?.how can i tell whats in it.


if i can say like this,
say you was in your car in 4th at 65.you need to go to 5th but you cant
it just rev out. wot is 4600 they say,mine will not stop 5000+its mad on rpms .thats why i tryed to over prop it and work back slow the wot.up it pich drop 300rpm?.not on mine with that 23p i can still rev the nuts of it 5000+.and that cant be right.

this is some of the jobs i like to get done now.and when i pull it out the shift cable to.

[seapuppy]

Gezy...I'm really suspecting your tach....can you rig up another tach to the engine and check the dash tach for accuracy....???....on your boat..the merc. drives are probably all the same..and a 23 p prop is a big prop for the drive...so...get a diagnostic tach and hook that up to the engine...have someone monitor the tach while you drive and call out numbers....

[gezy]

sorry did not think about that.

did it in the summer it was ok.

like i say it will pull like hell out of the hole then lose the plot and just rev out.

s, you will think it be over prop with that 23p.remember i was on about is in the summer.but i was thinking props then.like to me for that size boat
a 23p is over the top?.most boats with the same drive have got 19,21p
on them.+that 23 is s,steel type so no give.and i sent it to a prop shop to have it done up.b4 that i did spin it.

but with all 3 props i put on its the same.thats why i stoped buying props for it .run for the rest of the summer.

thats why a valve stuck on the new engine i did.that day it was on plane@4550 for 15 mins and valve and piston kiss .


im not mad about the speed .but if its good for it,it will be nice to get up there.
and its sticks in the back of your mind when you get up to 4000rpms .
kiss on the valve.
if i crank the engine by hand 360. and have a mate to see how much the prop will spin on that 360,can i do it like that?.

[seapuppy]

I'd contact maxum with your hin number..they might be able to tell you what drive gear ratio you have...that way you know what the manufacturer put it......just a thought...I'm not sure cranking the engine over by hand with it in gear will work...might be tough to do....here's another way to do this...
on the top of the drive is a cap...it has 4 silver looking star shaped bolts....I'd take those bolts out and gently tap the cap off drive..don't damage the oring gasket inside...clean off the oring and there the top gear is located...look on the gear for any numbers....if that doesn't work..then count the bull gear teeth...and the pinion gear teeth...that is your final drive...that will tell you if your at 2.2-1 or whatever the gear ratio is!....you can take that to your mercruiser mechanic and they can tell you exactly what drive you have.....

[gezy]

thanks ,s

i will do that.so they are not to bad of a job to swap then.

i was thinking you had to take the drive off to do this .and pull it apart.

so can i do this when the boat is still on the water or best tp pull it out.i think i can get at it ok.thanks,geraint

[seapuppy]

no gezy....you have to pull the boat out of the water to get this cap off....let us know what you come up with...but I also know you have to have the boat out of the water to pull the drive to change the gears out!!..