Tune-up

[Scott]

Hi Y'all, I've got a 1990 maxum. It has a mercrusier 3.0, 4-cyl engine that I'd like to tune up before I start it. I'll change the oil and plugs. Should I do something to the fuel system?

[mcoffey]

I am pretty sure those old 3.0 engines were point style and not electronic. So I would recommend replacing cap, rotor, points, condensor and plugs. Also, if all of this is original, I would consider replacing the coil and plug wires as well as they do fail over time. As for the fual system, may be a good idea to replace the fuel filter. I believe it is just a small screen right where fuel line connects to the carb. Even dumping some Seafoam or other fuel system cleaner might be worth it.

[ss3964spd]

Scott,

How long has it been since the engine had been running? Was the engine in running condition when the boat was "parked" before you aquired it?

From some of your other posts it kinda sounds like maybe you're not sure if it does/will run. If that's the case I would start out with doing the absolute minimum to get the engine started. Change oil and filter. If the boat has been sitting unused for a long time seriously consider draining the fuel tank and change the fuel filter, then add fresh gas. Install a fresh battery. Then hit the key.

My reasoning is this; if you don't already KNOW that the engine runs, and then you go replacing a bunch of stuff and it doesn't start, you won't have any idea if it isn't starting due to some problem that was already there, or a new problem with the parts you replaced.

Dan

[Scott]

Hi Dan,
They say it runs. Thawing out still but shits working so far. Oil looks good in engine, Cables, Steering, and throttle seems fine. hooking battery up tomarrrow to check bilge, lights, and trim. Before I start the engine thinking about full service or trying the river?

[ss3964spd]

Scott,

Just my opinion but I'd still see if it will start and run before I started replacing bits, but I also wouldn't put it in the water until you're confidant that it's in good working order.

For instance, if you don't know when the raw water impellor was last replaced you will want to verify that it works. To do so you'll need to put "muffs" on the drive, hook a hose up to the muffs, turn the water on, and start the engine. Don't rev the engine past, say 1500, and keep an eagle eye on the temp gauge. If you really have no idea when the last time the impellor was changed it would be an even better idea to replace it before you try to start the engine. If the impellor is old and the veins are brittle they could break off and end up in all sorts of places within the cooling passages - possibly causing a hard to find cooling problem.

Dan

[Scott]

Hi Dan,

I did get it to start engine sounded ok till the water started flowing from under intake/Exhaust manifold. Looking to remove manifold this weekend and check it out.

Scott