The Force power
Commander
- Joined
- Feb 3, 2019
- Messages
- 2,241
I was reading some of the earlier post on interchanging lower-units but they were for different years/application.
I have a 1990 model year(89 build) Force 90 hp motor with 2 spare (parts) Lower Units, they're all with a 2 piece drive-shaft
but the two "spares" are dual exhaust and the one on the motor is single port exhaust.
I read the Gear-ratio is the same on the lower-units and as far I was able to measure the mounting hole's location it seems to be the same;
my question is will a dual exhaust port lower unit affect the back pressure in the motor if it had a single exhaust-port?
I have a 1990 model year(89 build) Force 90 hp motor with 2 spare (parts) Lower Units, they're all with a 2 piece drive-shaft
but the two "spares" are dual exhaust and the one on the motor is single port exhaust.
I read the Gear-ratio is the same on the lower-units and as far I was able to measure the mounting hole's location it seems to be the same;
my question is will a dual exhaust port lower unit affect the back pressure in the motor if it had a single exhaust-port?