Merc Sportjet 120 - Upgrade or replace?

[a44yroldkid]

I have a 1997 Bayliner Jazz with the 120 HP Mercury Sportjet. I have searched for 2 years trying to get info on increasing the spunk in the motor and have not found anything! Since Bayliner offered the 175 Merc Sportjet as an option the same year shouldnt I be able to simply bolt in a 175? I am sure the pump is different also isnt it? I have considered selling my boat and simply buying another with the 175 already in it but the Jazz with a 175 is very popular and pricy. My boat although in immaculate condition wont bring much due to the 120 being underpowered for skiing etc. Seems everyone wants the jet boats that have adequate power. Imagine that. Any info is greatly appreciated.<br /><br />Thanks,<br />Mark

 

[JasonB]

Re: Merc Sportjet 120 - Upgrade or replace?

I don't have any first hand knowledge, but isn't a sportjet a pump with an outboard powerhead? I would think the pump would be the same, but you woul dlikely need a higher pitch impeller. OLutside that, I would think teh swap is possible, but have no idea about the particulars.

 

[kev_alaska]

Re: Merc Sportjet 120 - Upgrade or replace?

The sportjet is an outboard head with a jet. On some of them in riverboats here, they have enlarged the intake grate pattern and gone to a larger exhaust to increase the HP for the older ones. Just a thought..