overheat

My friend has a major problem and you guys have been very helpful to me on my triumph so here it goes. Let me lay a foundation. The boat is a hydro sport with a Johnson v4 130 hp both are 1995 models. The last time he ran it would go for about 2 minutes and the overheat alarm went off so he...

Let me set the stage. I want some advice before I subject myself to someone (i.e.: the mechanic) with an agenda for this to be a bigger problem. I just purchased this boat 2 weeks ago. There previous owner said it had a new impeller and lower unit was serviced. :) This is my first outboard and I...