How to check bravo 3 ratio

[Pavetim]

Is there anyway with the bravo 3 on and fully assembled to figure out its gear ratio? No tag or serial number in it.

 

[Bt Doctur]

a serial numer should be stamped into the housing on the port side about 4 inches down from the top

 

[Scott Danforth]

assuming the above mentioned stamped information is obliterated for what ever reason, turn input shaft, count prop revolutions

 

[Pavetim]

As i said its installed. So cannot turn input shaft but i get the feeling thats the only way

 

[Pavetim]

Maybe i can turn the engine? 1 turn of the crank sound be 1 turn on input shaft

 

[Bt Doctur]

Yes, thats true but dont use the nose bolt to turn the engine

 

[Pavetim]

Hmmmm how can i turn it then? Bump it over maybe but that wont be very accurate

 

[Pavetim]

I spun it by the prop shafts for 1 turn of the propnshaft i got 1.75 turns of the crank. Fuess that makes it a 1.81 ratio? It has 22P props on it

 

[AShipShow]

That should be correct... 1.81 is the lowest, the next closest would be 2.00, so sounds like you got it right. Only reason that would be different is for some reason the cone clutch is not fully engaged and its slipping slightly..

 

[Pavetim]

Oh geez. What makes the gear ratio all the gears or a certain one? I found a 2.0 drive for good price if easy change i can use a gear off this one to change it to 1.8

 

[alldodge]

I spun it by the prop shafts for 1 turn of the propnshaft i got 1.75 turns of the crank. Fuess that makes it a 1.81 ratio? It has 22P props on it

I sure wonder how ya spun the prop shaft and turned the motor

Need two folks
Find ratio by marking vibration damper and prop.
Shift in gear, then jump across the slave relay
Count 10 damper rotations then stop. Divide damper number by prop number

What is the issue as to why you want to change from what ever you have to a 2:0?

 

[Pavetim]

I spun it by using the inner prop shaft nut. Well i need to change prop shaft seal and just spent $400 on the tools and cannot even het the bearing carrier out so i think i am gonna need a new drive. Cant change just the lower unit either since they are corroded together and cannot seperate.

 

[alldodge]

Bummer, hope you were turning clockwise to loosen

Got a pick, that drive should come apart, there are 6 nuts and 2 bolts. Can also be another bolt if it is first gen B3

 

[Pavetim]

It should be an earlier bravo where is this third magical bolt? I removed 6 nuts, anodes and bolt that goes where the anode goes abouve props

 

[alldodge]

 

[Pavetim]

Yup removed all those

 

[Pavetim]

I found a rebuilt 2004 bravo 3 for 1500 but its a 2.20 ratio. I was told i can just swap the upper gear set and the driveshaft assembly which are all good on mine. Shouldnt even need shimming as i dont see shims in that section.

 

[alldodge]

Agree the difference in the 2:0 and 2:2 is done with gear set in upper section. Correct there is no shimming.

There is a difference in upper/lowers in early years and need to check

 

[Pavetim]

Well thats hard to say since mine doesnt have serial numbers but i am assuming its original so a 2000 the one i want to buy is a 2004 so think they are the same?