Ratios

jerryjudd1965

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Oct 20, 2020
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Hi iv fitted a bravo 3x ratio. 1.65 but my original drives were 2.1 ratio my props are 26 pitch but I’m finding it hard to get up on plane my engines are 5.7 efi 300 bhp how is it possible to at least get up on plain iv it seems iv lost quite a lot of power reason for buying different ratio these new legs were only 20 hrs and a massive price reduction any help or advice would be much appreciated
 

alldodge

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Going from a 2.0 and 26P props to a 1.65 drive, your going to need to drop the prop pitch to about 21

Even dropping to 21 your hole shot will be reduced because the motor doesn't develop the torque until the RPMs get higher
 

jerryjudd1965

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Oct 20, 2020
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Going from a 2.0 and 26P props to a 1.65 drive, your going to need to drop the prop pitch to about 21

Even dropping to 21 your hole shot will be reduced because the motor doesn't develop the torque until the RPMs get higher
Hi thank you for reply really appreciated And im
Glad I can at least do something I’m not really interested in speed all I would like to do is be able to get on plain We use boat mainly for pottering and as long as I can cruise at a comfortable speed around 18 to twenty knots that will be perfect also would it be possible if necessary to put gearing from my old bottom legs in to my new bottom legs thank you again for your help
 

alldodge

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would it be possible if necessary to put gearing from my old bottom legs in to my new bottom legs thank you again for your help

Yes, if both drives are standard gearing. The standard B3 drive gears are

32/27 upper for both 2.0 and 1.65
18/25 for 1.65
16/27 for 2.0

So if you change out the gears, you would have the original 2.0
 

jerryjudd1965

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Oct 20, 2020
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Yes, if both drives are standard gearing. The standard B3 drive gears are

32/27 upper for both 2.0 and 1.65
18/25 for 1.65
16/27 for 2.0

So if you change out the gears, you would have the original 2.0
Hi
Thank you again you have massively helped me and can’t thank you enough I really thought I’d made a massive mistake and iv found it very difficult to get an answer to any questions iv had on my new drives apparently my bottom unit gears are in good condition but casing is worse for wear And seen better days same as my tops hence having to source replacement stern drives and these were a massive reduction and I was advised to stop them up ASAP but was not told it would make quite a difference in performance but at least now you have put my mind at ease thank you again for your help
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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or put bigger motors in front of the drives
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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BTW, you would have had to jump to 8.2 liters to swing the 1.65:1 drives
 

jerryjudd1965

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Oct 20, 2020
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Lolol that would have been something unfortunately here in Gibraltar we are governed by hp as not allowed certain power due to number of factors across the straights
 

QBhoy

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Mar 10, 2016
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Tend to agree with above. You should think about asking a dealer to try out a set of 22” props for starters. Knowing the price of just one set of these props, never mind two sets...would make me want to be 100% certain of what set you need first.
 
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