1993 175 Hp Merc..Redline

[Stratosfied]

My friend who is new to boating bought a 93 Rig from his in-law. He took it out yesterday and at work last night said that he had it up to 7000 rpm. (and still had more) This is on an Astro 18' Fish and Ski. I told him that 7000 sounded a little high. My question, what is the redline for a 93 Merc 175 hp? Thanks in advance.

 

[quantumleap]

Re: 1993 175 Hp Merc..Redline

I believe he'd want to shoot for 5500 rpm's at WOT. If his tach is correct he's WAY underpropped or the prop has a spun hub. Tell him to check it out ASAP with another tach before he blows it up.

 

[LubeDude]

Re: 1993 175 Hp Merc..Redline

Yes, 5,500 is about right, you can run them up towards 6,000 with no problems, but the 7,000 is way out of the picture. I do not know what racers do to keep there engines from blowing up, but they run them to 10,000.

 

[Stratosfied]

Re: 1993 175 Hp Merc..Redline

Thanks Quantumleap, that was my thinking too but all of my motors have been Johnsons and I wasn't sure about the Mercs. I will show this to him. Thanks.

 

[Stratosfied]

Re: 1993 175 Hp Merc..Redline

Thank you LubeDude Too!

 

[KCLOST]

Re: 1993 175 Hp Merc..Redline

5600-5800 rpms at WOT....<br /><br />What's he got on that motor, an 18 pitch prop?<br /><br />Should be around 24p.... For Wide open running...<br /><br />But if that boat used to pull a lot of skiers, maybe that's why it is propped so low in pitch... Until he gets it rigged right for whatever he likes to do, he better pull back some!!!!<br /><br />What's the rpm reading at idle (out of gear)?

 

[Stratosfied]

Re: 1993 175 Hp Merc..Redline

Don't know the rpm @ idle, I will talk to him more tonight @ work. I know that he will be using the boat more for tubing/skiing etc. than fishing. Thanks for all the info and I will post more in the AM.