Broke in my 2012 Yamaha 75 HP 4-Stroke

[RangerGuy]

Ok so the break in went very well. I got through the first 3 hours without a hitch. I

am very happy with the boat & motor combo. I do have some questions and hoping somebody

can provide some input who is experience with setting engines up.

 

Below is a list of speeds & rpm's I recorded when the first 2 hours of breakin were completed.

 

These ranges have no trim. When I tried to trim I did not get any bow lift but got some bouncing. I have zero exprience with an aluminum boat like this

18' Alaskan Tiller so I have no idea what to expect. When running, the boat's bow kind of seemed to be diving a bit (but I'm not positive).

 

Also, I had a full tank of gas, no passengers or batteries, empty live well.

 

I am wondering if I need a different prop or to lift engine 1 bolt hole. Below are some pictures

and videos I captured.

 

(RPM @ GPS (MPH) with 0 trim)

 

idle speed is constant jumping around and is at.

 

750 @ 2.5 - just idling in forward

3000 @ 13.5 - just plaining, bow up a bit

4000 @ 22.7 - bow is lower

 

At these rpm's it kind of looks like the bow is diving a bit.

5000 @ 29 - 1/2 throttle

5500 @ 30 - 3/4 throttle

5900 @ 33 - full throttle

 

(I tried very little trim to lift bow and this was the result, I could have

easily over rev'd the engine if I added any more trim. Really I only touch the

trim switch for a very short period of time under 3 seconds, but no lift occured)

 

6000 (Max rated rpm) @ 36.5 - full throttle

 

Trim is @ 0 for these pics

 

Cavitation Plate Hieght

 

Prop view

 

Transom view in the water at the dock:

 

Engine Idling.. does this look like it's sitting way to low in the water?

http://www.youtube.com/watch?v=GL_HRrrvSts

 

Here are a view videos at different speeds. Does the cavitation

plate look like it's to low in the water?

 

3/4 Throttle

http://www.youtube.com/watch?v=SsUvDCaCzlE

[bigbuck]

Don't go messing with the setup of the boat until you have it rigged the way you want. Changing the height of the motor now is premature. As for trim, on a tiller it's used very little if I remember correctly. Enjoy the new ride.

[ecmilley]

motor height looks correct, wait till its loaded and rigged the way you intend to use it most of the time

[RangerGuy]

Thanks guys.. Yeh I'm gonna wait until I put the 2 trolling motor batteries in. I got the TM mounted yesterday and the wires run.

 

Just need the batteries and to do some crimping

 

 

Although, I'm pretty sure it's to low. In that last video you will see I can not see the cavitation plate and if the bow

is runnning to low now.. it will run even lower when there is wieght up front.

 

Just found a pretty cool thread on another board.

 

Engine Hieght

[Raf]

Thanks guys.. Yeh I'm gonna wait until I put the 2 trolling motor batteries in. I got the TM mounted yesterday and the wires run.

 

Just need the batteries and to do some crimping

 

 

Although, I'm pretty sure it's to low. In that last video you will see I can not see the cavitation plate and if the bow

is runnning to low now.. it will run even lower when there is wieght up front.

 

With the weight up front + maybe a passenger you will be able to trim out without porpoising (bouncing). I think the advice to wait until you have it equipped the way it typically will be is spot on.

[Terry]

I think your motor is a bit to low

but as others have said get everything on it before you start tinkering

[Tybo]

Your engine needs to go up one set of holes.The cavitation plate should be level with the bottom of the boat.

It is rare that the engine is sitting right down on the mount.

Also get rid of the double nut,This should not be used in high vibration areas.

Get some stover nut,It`s a must.

[RangerGuy]

Thanks Guys, I will wait.

 

Thanks Tybo, I will do that.. If I remember correctly my Ranger had those locking nuts with nylon, I will

see what they have at the marine, if they don't have them I will get them myself.

 

Also, it doesnt look like they put much silicone where the bolts are either. I can see a few globs

but certainly not nearly as much that was on my Ranger.

[Pigeontroller]

Proper trim is very important to good performance, you should be able to actually accelerate somewhat just by trimming the motor up once on plane...

[RangerGuy]

When a new boat needs to be adjusted like motor hieght etc.. is this something the owner ussually is charge for?

 

Or is it normally just included in the sale price?

[DRIFTER_016]

If you still have a porpoising issue when all is said and done add a pair of Smart Tabs.

Once adjusted they will combat the porpoising issue they will also give you better lift in the rear for getting you on plane faster and also being able to stay on plane at slower speeds.

 

Smart Tabs

[Billy Bob]

When a new boat needs to be adjusted like motor hieght etc.. is this something the owner ussually is charge for?

 

Or is it normally just included in the sale price?

 

I would expect the dealer was experienced in setting up this rig and it should of been good to go from the get go........but I'm sure they will correct it for no charge......a simple phone call should confirm that.

 

Nice Rig.........NOW GO CATCH A FISH....

 

Bob

[BillM]

If you've got porposing, you've over trimmed the motor..

[Sinker]

the alaskans have always been known to sit low in the water at the transom. Throw your two deep cycles in the bow, and it will help some.

 

Load that baby up with 10 dozen handcarved diver blocks, and you'll be good to go

 

S.

[jedimaster]

You can look for a prop that is designed to give stern lift, like a cleaver. This will get more boat out of the water and reduce your drag. Since you lose bow lift with a stern lifting prop, this can have a negative affect but if you are already porpusing and you get out of the hole ok, then you could likely be ok with losing some bow lift. But don't forget you are driving an allumium boat and not a bass boat.

[chris.brock]

Only 4 mph difference between 1/2 throttle and full throttle, I'd be doing alot of cruising at 1/2 throttle to get around, probably save a ton of fuel with little loss of speed

[Steve Piggott]

Dose the motor pull when you have it trimmed down? I trim my 20ft Lund tiller until there is no pull on the tiller handle and is easy to steer left or right.

[RangerGuy]

Specs on the motor say 75hp @ 5500 if I remember correctly so that's probably why there isn't much diff between 1/2 or full throttle

 

There is no torque for me at any speed this surprises me. It's much easier to drive than my old 60hp Johnson 2 stroke.

 

The transom isn't actually riding that low concidering it's only a 20" transom.

 

 

 

I'll run it again on Saturday with the batteries in and see what she does.

Edited June 12, 2012 by RangerGuy

[Mike the Pike]

Specs on the motor say 75hp @ 5500 if I remember correctly so that's probably why there isn't much diff between 1/2 or full throttle

 

There is no torque for me at any speed this surprises me. It's much easier to drive than my old 60hp Johnson 2 stroke.

 

The transom isn't actually riding that low concidering it's only a 20" transom.

 

 

 

I'll run it again on Saturday with the batteries in and see what she does.

 

 

Just leave it the way it is.Seems normal.

 

I have a Lund 1660 Classic with a Yamaha F60 tiller I get trimmed out and Max is 5400 rpm. Top speed is around 34 mph with 2 fisherman plus gear sometimes 35 mph alone.

 

36.5 MPH sounds about right considering your boat is long.

 

Enjoy the new toy and you need to change your board name to Lund Guy.

[Dara]

How are you measuring your RPM

 

If its an analog, dial, it could be off...When I got my 60 a couple years ago the RPM gauge had to be adjusted...still getting around to getting the connectors to hook it to the HDS7..one a these days

[Mike the Pike]

How are you measuring your RPM

 

If its an analog, dial, it could be off...When I got my 60 a couple years ago the RPM gauge had to be adjusted...still getting around to getting the connectors to hook it to the HDS7..one a these days

 

Dara if you are asking about my 60 Yamaha I have a digital tachometer completely separate from the Sonar.

[doubleheader]

All good advice, get her set-up they way you plan to use her, and get a few more hours on her before doing anything. That said the motor is sitting low, considerably lower than my Honda sat on my Alaskan.

[RangerGuy]

Dara, the motor is running a analog yamaha tach with 2 warning lights. I would think it's off but it's idle numbers are dead on?

Could it still be off, maybe I should pull it and make sure the dip switches are set right?

 

 

 

doubleheader, did you get much bow lift in your alaskan or was it a very flat running boat and required very little trim?