87 Merc w/ Alpha Overheating - Again...

[87 Winns]

Hello,

I have a 1987 Merc Alpha out drive with 500 hours.

Hope you can help me here. Last year I had the out-drive rebuilt with new impeller as it was 7 years since new one was installed as it was running hot when I launched for the first time.

It then ran great all summer.

Yesterday after launch for the first time again, it started to run hot when at no wake.
With faster speed it cooled down.

Can this 1 year old impeller be bad already???

Thanks!

 

[Eric 3.7LX Alpha 1]

If it's ever been started without water on to the drive, the impeller could be toast in no time. It doesn't take long...

 

[87 Winns]

Eric - Thank you for the info. I always use muffs in the driveway....

Could there maybe be some sand in there that needs to get flushed out?

 

[Eric 3.7LX Alpha 1]

Do you think you ran aground your first time out? That would definitely do it. Something as simple as a plastic bag in the water getting sucked into the water inlet could cause trouble.

 

[87 Winns]

I didn't run aground as our lake levels here are 12" higher than last year. I'm just wondering if I may have picked up a plastic bag....I'll just keep an eye on it.

 

[87 Winns]

Sorry, another question, I have read the manifold may be bad. They are original with 500 hours. Could this be it?

 

[crazy charlie]

I would check the risers.Charlie