lower units

[88xr4merc]

I have an 88 xr4 blackmax 150 the lower unit gear ratio is 1.78 can I put a 1.87 gear ratio on it or will it mess up my motor

 

[Faztbullet]

Re: lower units

can I put a 1.87 gear ratio on it or will it mess up my motor

Wont mess up motor but it will be a little slower on hole shot and you may have to change pitch of prop. The prop you have now will fit but the exhaust will blow around the hub like a chopper prop so watch for excessive cavitation on planing.

 

[88xr4merc]

Re: lower units

Which prop and pitch should I get

 

[Mi duckdown]

Re: lower units

I would get the boat/ motor running first. Run and check RPM and speed(GPS). then the the prop can be figured out.