1994 mercury 225 3.0 L Gear Ratio?

stevedallas28

Recruit
Joined
Mar 14, 2005
Messages
2
Can anyone confirm that the ratio is 1.64? I have only been able to find one reference to this number online. Thanks
 

rabidfish

Senior Chief Petty Officer
Joined
Oct 3, 2000
Messages
788
Re: 1994 mercury 225 3.0 L Gear Ratio?

There are some units with other ratios:<br /><br />1.62:1<br />1.64:1<br />1.75:1<br />1.87:1<br /><br />You need to count teeth to be absolutely certain
 

stevedallas28

Recruit
Joined
Mar 14, 2005
Messages
2
Re: 1994 mercury 225 3.0 L Gear Ratio?

that is not really what I wanted to hear but thanks alot for the response. <br /><br />Can you tell by serial number? or is counting teeth like you say the only way. Sorry for the dumb questions.
 

rabidfish

Senior Chief Petty Officer
Joined
Oct 3, 2000
Messages
788
Re: 1994 mercury 225 3.0 L Gear Ratio?

No dumb questions here....<br /><br />The only "accurate" way is to count teeth.<br /><br />You only have to remove the bearing carrier to count the teeth.
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: 1994 mercury 225 3.0 L Gear Ratio?

Need to do the rotation count method...<br /><br />Turn the drive shaft twenty to thirty times... Mark a line on the drive shaft just above the water pump to give yourself reference... Also mark a line on the prop and the lower unit case...<br /><br />Like I said turn the drive shaft 20-30 times (maybe even more to be more accurate in the end) and as you are doing this keep track of how many rotations you have on the prop...<br /><br />For instance 20 drive shaft rotations results in 12.34 rotations of the prop...<br />20/12.34=1.62<br /><br /><br />The problem might be determining the difference between a 1.62 and 1.64 ratio... So that is why it is better to turn the drive shaft many more revolutions to give you a little bit more difference in the ending prop revolutions for each ratio.<br /><br />For instance...<br /><br />40 drive shaft revolutions/1.62 ratio = 24.69 prop revolutions<br /><br />40 drive shaft revolutions/1.64 ratio = 24.39 prop revolutions<br /><br />You get the idea...<br />If the lower unit is in forward gear you can do the same by turning the prop instead of the driveshft... But it's (drive shaft turns/prop turns) no matter the case..<br />Also, you will have to pull the lower unit off to do this... Have fun!!!!
 
Top