Mercruiser overheating

Flash · Posted: Jun 02, 2003 6:58 am Post subject: Mercruiser overheating

I have a 315 HP mercruiser in a 01 Tige 21i. Yesterday it overheated a few minutes after I got it in the water. I turned it off, and got towed back in. The intake was not blocked, but it does not apper to be pulling any water. Does this sound like the impeller? Is the impeller located in the pump housing at the bottom left of the motor? How hard is this to change, and what do the parts cost.

Thanks in advance.

C-Stone · Posted: Jun 02, 2003 8:07 am Post subject:

Most likely the impellor, shouldnt cost to much to just take it in to a shop.

PimpinD · Addict Joined: 17 Feb 2003 Posts: 785 City: Orlando, FL

dont take it into the shop, it should take like 30mins t ochange, if u are having trouble getting the old one out, urs a wrench that can be adjusted to clamp on and a screw driver and a peice of wood to remove it if u dont have the ride tool, it work perfectly for us. and thew dealer will end up breaking something else and causing u more problems ..

Millertyme · Posted: Jun 02, 2003 3:55 pm Post subject:

Did you start your boat out of the water or without a flush kit attached? If you start your boat when its dry you will cook your impeller in a few seconds. New impeller is about 30 bucks. Make sure you dont put it in backwards.

snowboardcorey · Posted: Jun 03, 2003 5:49 am Post subject:

Yeah, an impellar is just routine maintinance, I would suggest at least attempting it your self, its a pretty simple installation. Although I am not sure that you can actually install an impellar backwards, I think the revolution of the water pump would position the impellar blades correctly even if they were installed facing the wrong direction. I suppose when you buy the impellar it wouldnt hurt to ask.

cbush325 · Newbie Joined: 04 Mar 2003 Posts: 6 City: Birmingham

I have a pcm 351 it is possible to put the impellar housing in backwards mark the intake house and the output hose prior to taking it apart trust me.

C-Stone · Posted: Jun 04, 2003 10:31 pm Post subject:

Its not possible to put the impellor in backwards, and the impellar blades will position themselves correctly once you have started the boat, I usually spray the impellor and houseing with soapy water so there isnt a dry start up(after replaceing). Depending what engine,v drive or direct and which type of houseing setup you have it can be done on the water or should be taken to shop, some houseing have gaskets and o-rings and backing plates, not to mention removing the belts, water intake house etc. etc. you could find youreself overwhelmed quickly. You also may find it to leak after doing so, and then start over again to correct the leak.