Local dealer is telling me that 1.65 ratio is not...

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

Gonna fix tach this week and take it out again when I get another lower unit....... what RPM should I be looking for at WOT? 4500ish?

 

[180shabah]

Re: Local dealer is telling me that 1.65 ratio is not...

4400-4800

 

[HT32BSX115]

Re: Local dealer is telling me that 1.65 ratio is not...

4400-4800

Try to "prop" it so that you're turning closer to 4800 too

 

[Howard Sterndrive]

Re: Local dealer is telling me that 1.65 ratio is not...

Ratio stamped on the housing doesn't mean much either. Need to count revolutions or count gear teeth to determine what ratio gears are inside.
I have a housing sitting on my bench stamped 1.98 that has 1.84 gears in it.

 

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

I have my cover off the drive..... I'm to count the two large gears up top, correct?

Thanks
Dave

 

[180shabah]

Re: Local dealer is telling me that 1.65 ratio is not...

Yes count the teeth -

You still haven't answered the question - what is the problem/what are you trying to fix?

Just check the merc website - standard ratio for a carbed 5.0 is 1.62:1 or the 1.81:1 for high altitude. There is nothing wrong with what you have.

The MPI 5.0 is listed with either the 1.47 or the 1.62 but still suggests the 1.81 for high altitude.

 

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

Howard Sterndrive..... that's a great name!

Thanks to everyone who has helped me!!

 

[180shabah]

Re: Local dealer is telling me that 1.65 ratio is not...

FWIW v6 ratios are:

4.3TKS 1.62, 1.81 and 2.0 for high altitude
4.3MPI 1.47, 1.62 and 1.81 for high altitude

 

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

I had a lower unit go out that started all of this....... when the lower unit took a crap I took my drive to the dealer for an inspection and that's when they told me that the drive is incorrect for the engine, etc... So I posted here to confirm or negate what they said.

 

[180shabah]

Re: Local dealer is telling me that 1.65 ratio is not...

I would be cautious with this dealer. Are the techs factory certified?

 

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

To the best of my knowledge they are. I'll double check that when I'm over there again.

 

[HT32BSX115]

Re: Local dealer is telling me that 1.65 ratio is not...

Turn the input shaft one revolution, how many revolutions did the prop turn?

It is REALLY hard to do a ratio check by only turning the input shaft only 1 turn and counting prop "turns" (Mainly because you don't even get 1 turn of the prop......

Turn the input shaft exactly 16 1/2 turns and have a helper count turns of the prop......it should be exactly 10 if you REALLY have a 1.65:1 drive.


Cheers,

Rick

 

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

Okay, I finally got time to post back on this. My tach is working (hooked up an after market autometer for now) and WOT is 4000 RPM's. My current prop is 21 pitch. Sounds like I need more RPM...... I need to go to higher pitch, e.g. 22, 23?

Best
Dave

 

[Maclin]

Re: Local dealer is telling me that 1.65 ratio is not...

You need to go down in pitch, like a 19, to get more rpm.

 

[bluemarshboater]

Re: Local dealer is telling me that 1.65 ratio is not...

Thank you.