Another Mercury Alpha I impeller question

[cbear34]

I am a recent boat owner and took the boat out today for a test run to make sure everything is working well. I own a 1989 Maxum 2000sr with a mercury 305/230hp Alpha I drive. Motor runs great and everything worked well. Noticed at cruising speed engine temp was fine, 160 to 170 degrees at 2500 rpm's 20 to 25 mph. At WOT the engine temp climbed and warning sensor sounded. Oil pressure was fine but engine temp climbed over 200 degrees. Immediately we shut down the engine to prevent any overheating problem and let it cool down. Started back up after a while and everything was fine again at cruising speed. Had no further problems. After reading posts on this forum about engine hot problems, I am pretty sure the impeller is bad. Read the stern drive manual and was wondering how long does it take to replace the impeller? Seems pretty straight forward to replace.

 

[alaska_av8r]

Re: Another Mercury Alpha I impeller question

I am a total novice and it took about 4 hours on mine.....I had taken the lower unit off before....so that knowledge helped.....just take your time...its not too hard a job to do.

 

[JustJason]

Re: Another Mercury Alpha I impeller question

impeller replacement is supposed to happen at 200 hours or 2 years... whichever occurs first.
If you don't know the last time it's been changed... then probably best off replacing it.
if you had 1 quick rise in temperature that hasn't repeated itself, it's entirely possible that you had some seaweed or other debris (plastic bag) that wraped itself around the drive. that happens all the time to

 

[cbear34]

Re: Another Mercury Alpha I impeller question

Thanks for the info. It's been longer than 2 years so I figured it needs to be replaced after searching for info on this forum. The first thing we checked was for something wrapped around the drive, but found it clean. I figure since it needs to be done on a regular basis, I might as well learn how to do it. I am a mechanic so i figure that knowledge will help. Thanks again for the info.

 

[Haut Medoc]

Re: Another Mercury Alpha I impeller question

Here is a frre link to the online manual.....
http://www.boatfix.com/merc/Servmanl/6/6A2R3.PDF
Click on the lettered sections on page seven to download the section that you want to view....​

 

[terrylee]

Re: Another Mercury Alpha I impeller question

Hello just wanted to say everyone on this forum is great I just changed my impellar thanks to these guys well if you want some good directions go to http:// mercstuff.com/waterpumpinst.htm these are very good directions.

Good luck!!

 

[cbear34]

Re: Another Mercury Alpha I impeller question

Thanks again for all the good info. I did read the mercstuff.com instructions and they seem to be straight forward and easy to follow. I figure since this has to be done regularly and I am a mechanic, I might as well learn how to replace the impeller.
Thanks Haut for the link. I'll also check it out.
This forum has been a great help for a recent boat owner to learn all the tricks of boat ownership.

 

[Prop Buster]

Re: Another Mercury Alpha I impeller question

Hey Buddy,

Please read my recent post called "Older Alpha Unit Lower Unit Problem"

I should have reworded it, but it was somethig we found that is happening to the "older" outdrives out there.It deals with overheating and my Marina has three lower units with this affliction.

If you have the lower unit off and are replacing the implellar, PLEASE check this out as well to save time, money and more headaches....

Good luck to you.

Prop Buster

 

[cbear34]

Re: Another Mercury Alpha I impeller question

Hi Prop Buster,
Yes, I saw your post about the older merc lower units. Thanks for the info. I will certainly check it thoroughly when I have it apart. Hopefully all it is, is just a bad impeller!