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Lower unit/propeller help

1

1989wellcraft

New member
ok guys so im new and idk if im posting this on the right thread but here it is, i have a 89 wellcraft with a 3.7L 4 clyc, with a alpha 1 sterndrive, last week i hit rocks with my lower unit and busted a hole in it and destroyed my prop, and a buddy of mine found a lower unit, a "freebie" what it came off of as far as a 4 clyc, v6 or v8 im not sure and niether is he, i know the gears arn't the same as my old one because its truning up way too many rpms, alsome hole-shot but no top-speed and on deceleration the boat actually bogs down and sometimes dies, old prop was a 19 pitch, the one i have on there now im not sure what it is, but my question is would just changing the prop correct this problem?
 
need to know what size prop is on there now, gear ratio`s are done in the upper unit. you could just swap your lower unit, not the whole drive.
 
Look on the left side of the outdrive (facing the back ofvthe boat from the outside) around the mercrusier label and red stripe for a number one should be the gear ratio the other is serial number.
If you can't find it, pull off the top cap and count the teeth on both gears. That will give you a starting point. Others will tell you what to do from there.
 
all i did was swap the lower unit not the whole stren drive, and im not sure are the lower units geared different? and i have no idea what pitch the one is on there now, but im getting my 19 pitch one fixxed as we speak so i was gonna try that one out and see what happens, but my real question is if the lower unit does have different gears in it which idk if they do would a prop change fix my problem? beacuse everything else on the lower unit was the same shaft and all as the one i broke. and as far as stamp on the side its not the factory stren drive its a SEI106 i believe..
 
NO

All Alpha one outdrives, the lowers have the same gear set up.

The gear ratio is contriolled by the gears in the upper gear housing.

End of story.

Having a prop rebiult is the cheap way out. Aluminum props DONT get rebiult to factory standards. They are not cupped like a new one.
This causes higher rpms and less top speed and somewhat less of a hole shot.

Otherwise they are good if in rocky water knowing you will waiste it agian.........
 
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