Re: 1986 Mercury 150 XR2
The motor is a 60 degree V-6 engine and has a long history of high reliability. The same basic design is still used today. The oil system is very reliable when serviced and tested regularly (every 100 hours). Take note of John Martin's recommendation and the others, and you shouldn't have any problems with it.
One of the problems you are likely to encounter with an engine that has been sitting this long is varnish buildup in the carbs. You might be served well by taking the time to clean and rebuild them now. You should also replace all the hoses to avoid any problems with the newer oxiginated fuels.
You will also need to add a fuel/water separating filter to your fuel system to run today's fuels. This would be the case no matter what engine you wanted to run.
Remove the spark plugs and spray fogging oil into the cylinders while rotating the engine by hand. It won't hurt to spray some into the carb intakes also. This will provide a base of lubrication since much of the lube that was in the engine is probably now pooled in the lower crankshaft bearing.
When you get the motor running, do not rap the throttle. You can slowly increase the engine speed up to 1500 RPM on the hose if you want.
Once you get it on the water, treat it like it was a new motor and go through the break in procedures in the owners manual. If you don't have one you can get one from
www.mercurymarine.com. They're fairly inexpensive. The reason for the rebreak-in is to ensure that everthing has a chance to get well lubed and any sticky parts (rings, etc) have a chance to loosen up. It will also give you a chance to identify any problems and correct them before they have an opportunity to cause extensive damage.
Taking these few, small, inexpensive precautionary steps will help to ensure that motor continues to live a good long life.
Hope this helps... it's what I would do if I was lucky enough to be given an engine like yours.
