Preventative maintenance advice

[Keith_Menard]

I have a 2003 Gekko with a Mercruiser Mag 5.7. I am looking for a tuneup kit, a recommendation on an alternator (this one looks original), and some instructions on how to change the impeller.

 

Thank you!

 

 

[skihacker]

I had a carbed version of that motor in my fist malibu. If the alternator isn't acting up your probably fine to leave it. My 2 cents on tune up parts is discount inboard marine, call first to verify correct parts. The impeller is a bit if a pita, as i recall you need to remove the drive belt and take the pump off the motor, then take the pump apart.

[Mastercraft81SnS]

Why do you want an alternator? Is there any thing going on with your charging system? My 81 has the original alternator on it and it works fine. To change the water pump you have to take the belt off the engine. I found this link on how to replace the water pump hope it helps.

http://www.smwebhead.com/phpBB3/viewtopic.php?f=11&t=7491

[Gar]

I've never had that kind of luck with an alternator. If you ski on A big lake or way away from help, may be good to buy a new one. If not you could run it until it quits.

[6balls]

If you are not a mechanical guy...take cell phone pics step by step as you dis-assemble housings etc even for an impeller so you can put it back together right...easy to do and worth it.

 

[Jordan]

Where the heck did they hide the raw water pump?

[Keith_Menard]

I have noticed when I turn on any accessories the battery just can't keep up...and when I checked the battery today I noticed it is probably on the back 9. It could be as simple as that...just the battery, but it seemed to me if I was taking off the belt, changing the alternator was cheap insurance.

[skihacker]

Raw water pump is bottom left in the pic

[countymountie]

When I changed out my impeller, it was just a lot easier to pull out the whole pump assembly and change it out on the workbench.

[DW]

@"Keith Menard" : You might check voltage readings with a good known voltmeter (not the dash unit) to see if the battery is being charged when the engine is spinning. Usually, alternators are good / bad. I actually found one at a starter repair shop (I needed the housing due to a crack, not a faulty alternator).

 

Raw water pump is a Jabsco unit, remove it from the boat to service as noted above. Pretty simple remove the housing that is held together by the six bolts, you will need some sort of puller (a paint can opener works / needle nose pliers will also work) to pull the impeller out. Make sure you note which way the vanes are bent, I suggest marking the housing as to rotation, which bolts attach the mount, Inlet and Outlet ports with a silver sharpie so you reassemble as you took it apart. Inspect the housing for cracks and any wear marks from the impeller.

[Orlando76]

How old is the battery? I very highly doubt the alternator is in less than good condition and no doubt better built than a reman which is most likely what you will find. Keep in mind an auto alternator is a hazard in a boat so don't let the alternator shop tell you otherwise. I'd replace the battery with a brand new Deka and report back.

[oldjeep]

Spray some wd40 or any other lube in the housing half with the impeller in it, then try to turn it with the pulley a quarter turn to break it loose. They can be a pain to pull out after siting all winter. Then make sure to clean the wd40 off and use the glycerin packet that should come with the new impeller to ease reinstall. If it doesn't have a packet then a little dish soap works fine.