Mercury 115 4-Stroke Break In RPM Question

2014 Tracker Pro Guide V 175

As the title states, I just did the 2 hour break-in according to the manual last weekend. Full tank of gas (21 gallons) and four of us, not much gear. When performing the max RPM intervals, I only hit 5100 - 5200. Granted the max range according to the manual is 5000 - 6000, but I think I should be closer to the middle of the range. I don't know the max speed cause I didn't have GPS and the speedometer line had a splice in it shooting out water so it wasn't accurate.

The hole shot was significantly better with persons weight moved forward, very sluggish with the two rear seats filled. Boat came with a 3-blade aluminum prop 17p pitch. Oh and the gear ratio is the 2.07:1.

Any thoughts? I'm wondering if I need to drop to a 15 pitch, but I also figure the engine needs more time to break in first. I will be going out this weekend with the new fishfinder that has GPS speed.

Dont know if I would mess with it much........will you have four in the boat often? with two I would expect the rpm's to come up atleast 200-300

If you think you will have four people in the boat regularly I would look into smart tabs, you will be amazed at how they help the boat.

First, you have a long way to go with the break-in. Vary the speed constantly, and make sure to hit max rpms several times a day, but only briefly. You are helping set the rings and build compression. Take your time and do it right.

Did you tuck the motor all the way down, and then trim up as you gain speed? Could be that you has the motor too far down to reach full rpms.

-TH

3-4 folks would be the normal average. I did have the motor trimmed all the way down on acceleration and trimmed up when on plane and still didn't go past 5100. I varied the throttle between 3500 and 4500 rpms every 3-5 minutes. I'll report back with more specifics this weekend. Thanks for the help!

Two hours is not enough break in time. Run it and vary speed and when you get 10 more hours on it then see what your max rpm shows. Some of these new engines have the computers set not to open up fully untill a set number of hours.

Good point G, I will keep at it thanks!

Also, I'd recommend you do most of the break-in with the boat lightly loaded. You don't want to stress it just yet.

-TH

X2 on what G said.

I have a new 140 HP and although I've been in it two to three times a week, I'm just now passing the 10 hr break in period recommended by the manufacturer.

I will say that I have a stainless prop and I don't have any issues coming out of the hole. I wouldn't address anything until after you get past 10 hrs.

2nd trip today, got another couple hours on. Was like a different boat already. Had GPS on the fishfinder. Max speed was 40.2 mph at 5600 RPM WOT. What I did notice today is a lot of blow out on turns even at cruising speed, gotta trim down a bit first, but otherwise it is coming along nicely.

A 18 pitch three blade Stainless prop would probably be close to ideal on your boat and motor......But I would not fool with trying it untill after break in.

4 blade will help in turns.