Logo

197615hp/1990 909hp interchangeability

Billyjackreally

New member
I always thought that the difference between a 15 and a 9.9 was just carburation. Wifes cuz gave me a 76 power head 15hp so i traded an older 25 hp for a 1990 9.9 thinking ok ill just swap the bottoms. Looking in the parts lists i find the driveshaft is a different number starting at 1985 and going to or past 1990 so my question is this and it may be the most inane one on here tonight. Different part number means different parts or just the number changed ???:mad::confused:
 
The older drive shaft had a groove cut in it for an o-ring to seal the spline.The 1990 had a seal as part of the lower crank seal assembly and no groove.----The 1990 lower unit will bolt onto the 76 exhaust housing. On various years there is more to it than just a bigger bore carburetor !!!
 
The older drive shaft had a groove cut in it for an o-ring to seal the spline.The 1990 had a seal as part of the lower crank seal assembly and no groove.----The 1990 lower unit will bolt onto the 76 exhaust housing. On various years there is more to it than just a bigger bore carburetor !!!
I have the original driveshaft for it - only thing about That lower unit is the prev owner tried to "Fix " the gearcase unsuccessfully so if i use the older driveshaft and the newer lower unit( gearcase) and cross my fingers about the impeller groove i may get it running? Thats what i was wondering and wanted to find out before i tore it apart and got parts all over the garage which seems like i often do- i didnt know if the spines were the same or not so Thanks a bunch ! Now i am hoping i do not have to go shopping for yet another lower unit as i already have a spare 40hp one kicking around LOL:D
 
Back
Top