Did I get the wrong ratio?

[Grec]

The engine in my boat is a Mercruiser 5.7L 260MR. When I ordered my drive in April, the dealer told me he thought it would take a 1.5:1. He then called me the next day and said that SE told him it should be 1.65:1 and so that is what he ordered. He said if it was wrong, it was no major problem. It would just require a different prop.

When I ran the boat with the new drive, it seemed sluggish. I bought the boat knowing that it needed a new drive, so I never personally saw how it accelerated with the old drive, but the previous owner told me that the boat cruised at around 22 MPH and topped out at about 32MPH.

With the new drive, I'm cruising at about 17MPH and I top out at around 24MPH.

It also seems pretty slow to accelerate and reach a plane. As I said, I don't have any previous reference to compare it to, but the boat always feels like it is struggling to move along.

By coincidence, today I happened across the original manual in a locker behind the dash.

The manual lists the standard ratio as 1.5:1 with an option to use 1.32:1. (I don't know what this option is or why you would choose it). The point is, they don't list anything above 1.5:1.

They also list the RPM range at WOT as 4200 - 4600. My RPM at WOT is right around 3800.

My dealer told me to bring him the old prop and he would take a look at it and let me know what prop I should change to. Before I spend money on a new prop, I'd like to know if this is the right approach to solving the problem.

Thanks in advance for your assistance.

[Technical Support]

A 1.5 ratio would actually make your problem worse. I would say that you have an engine problem, or the wrong prop.

If you have the old drive you can count the teeth to make sure the new drive is the proper ratio.

If you have any questions feel free to give us a call.

Tech Support

727-461-0811

[Grec]

Thanks,

I appreciate the quick response time on this board. I'll give a call.

[Grec]

Okay, in case anyone is following this thread, here is the outcome:

The drive I have is a 1.5:1. Apparently when the dealer called me to tell me he was getting the 1.65:1, it was because he hadn't given SE the year of the engine. Subsequent to telling me it would be a 1.65:1, he called them back with the year and they sent the 1.5:1. The dealer just forgot to tell me about the last conversation with them, so I was of the impression I had the 1.65:1.

Having said all that, I still had the problem of not reaching the proper RPM at WOT. The dealer switched me to a larger prop with a lower pitch and now I'm right where I should be.

The bottom line however, is that solving this took several conversations with the dealer and with SE. I can honestly say that I have never dealt with a company with a better technical department than SE.

I've called several times with questions in hopes of getting back on the water, and every time I was given quick, accurate answers that set me in the right direction to solve my problem. No waiting on hold for an hour. No evasive or qualified responses. Just direct answers to help solve the problem.

If I ever need another outdrive, I don't think I'd ever consider anything but an SE.

Thanks!