3.0L Mercruiser Runs Warm/ noise from outdrive

[Sandman18]

I have a 1987 18' Imperial Bowrider with a 3.0L Mercruiser I/O with the Aplha one outdrive. When I got the boat it would not engauge into reverse. I found that the shift cable on the ****er had slipped out of the bracket so the cable would not move the full movement. I fixed that and made sure without the boat running that it would shift into foreward and reverse. After taking out in the water after being at full throttle from about 20 mins you start to hear a clicking sound from the outdrive and then the temp gauge starts to climb. If I shift it out of gear into neutral the noise will stop and then the temp will move back down to normal. I assume that it must be slipping out of gear and I assume that affects the raw water pump but i'm honestly not that familiar with the way it works. Im very knowledgeable with cars but not boats. Any help would be appreciated.

 

[Bt Doctur]

Re: 3.0L Mercruiser Runs Warm/ noise from outdrive

In the Adults section are manuals for your engine and drive.
Well worth reading.

 

[brian_mcwhirter]

Re: 3.0L Mercruiser Runs Warm/ noise from outdrive

The shifting in the Alpha One happens in the lower unit, so if it makes a clicking noise in gear, but not in neutral, you've probably got a lower unit issue. I'd probably start by looking at the gear oil (level and contaminants). If the clicking noise started after the 20 minute run, you probably should have checked the oil level before you started. Hindsight, and all that. . .

Regarding the overheating issue, if you're running WOT for 20 minutes and starting to overheat, you probably have a worn impeller, which is unrelated to your clicking problem. The good news is, the impeller is in the lower unit, so you can fix them both at the same time.

If, like you say, the shift cable was not in the bracket when you purchased the boat, there's probably any number of problems you're going to need to work through. Been there myself. Good luck. . .