Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Skipper
Posts: 11
Registered: ‎11-03-2014

Having trouble getting traction.

I have a work boat, an aluminum pontoon with a 20" transom, on which I mounted an E150STLESB. The motor has a 19 pitch prop. I started with the motor mounted on the lowest hole, and the bow was too low at speed, the motor was slipping like a car spinning its wheels. The only way to get going was to trim the motor all the way down which exasperated the "bow too low" problem. The pontoons were cutting through the water instead of lifting and running like one would expect.

 

I then raised the motor all the way up on the transom, which put the motor vent plate about 1" below the bottom of the transom and things were different, it went faster, but with the same problems as before, bow too low and it only gets traction if its tilted all the way down, leaning way back.

 

Because we work off the front of this boat, it is set up with the front half of the boat pretty much empty. I kinda thought I might have the opposite problem, bow too high.

 

Thanks in advance for any input.

Highlighted
Admiral
Posts: 8,571
Registered: ‎07-14-2011

Re: Having trouble getting traction.

Not being a typical recreational boat, your craft is unique in the way it is used, so much will have to be trial and error to find a solution.

 

What is the top rpm the motor reaches at WOT? I am guessing that a 19" prop may be a bit large for a work boat. You would want to see about 5500 rpm.

 

Changing the prop style may help or trying a 4 blade design. If you have a dealer who will work with you, testing a Rebel and a Cyclone prop to get to the 5500 rpm range may be an improvement.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Highlighted
Skipper
Posts: 11
Registered: ‎11-03-2014

Re: Having trouble getting traction.

I have a hand held touchless tach that was reading 4100 RPM, but it was a little unnerving to go WOT because the bow was plowing and as you can imagine the steering was strange.

 

I can see a lower pitch prop causing some of the traction problem but there is something I'm not understanding about how flat this boat wants to ride. Do you think a lower pitch prop would give me the traction I need to tilt the motor and get the bow up?

 

 

Highlighted
Admiral
Posts: 8,571
Registered: ‎07-14-2011

Re: Having trouble getting traction.

If you only reached 4100 rpm, then either the tach was on the wrong setting or the motor is severely overloaded or not running correctly. It should be around 5500 rpm.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Highlighted
Skipper
Posts: 11
Registered: ‎11-03-2014

Re: Having trouble getting traction.

[ Edited ]

Like I said, it was plowing through the water, not up on plane. That plowing is what is keeping the RPMs low I'm guessing.

 

I'll try to find a better tach option and a lower pitch prop to see what happens.

 

 

Highlighted
Skipper
Posts: 11
Registered: ‎11-03-2014

Re: Having trouble getting traction.

transom - 1.jpg

 

 

Changed the prop to a 15 pitch, actually made it worse. Here's a picture showing the motor in top position on the transom. The boat is sitting on a flatbed. Is it still too low?

 

Highlighted
Skipper
Posts: 3
Registered: ‎08-29-2013

Re: Having trouble getting traction.

I agree with Bill, work boats are a totally different scenario.  A lot of factors come into play with them like total weight and distribution, log diameter length and configuration, bow shape etc etc.  The more information you can give us the easier it will be to lend a hand in diagnosis as any one or more of multiple variables could be causing the problem.  The image you posted looks close to right for a work boat height in relation to the transom pod but how it sits in the water is also important.  

 

 

Highlighted
Skipper
Posts: 11
Registered: ‎11-03-2014

Re: Having trouble getting traction.

[ Edited ]

In looking at the transom and motor, I noticed if I drew a line down the transom and extended that line past the motor, it crossed the propeller about midway. So as I got up and planed off, the water flowing over the lower unit is extremely disturbed by the transom plowing through the water.

 

I dropped the motor to the bottom setting, and I then cut the bottom of the transom and reshaped it. Now the transom is closer to 17" instead of 20". At this point it is not great, but it works. The 15 pitch prop now gets me to about 5500 RPM.

 

These pontoon transoms are very different than a flat bottom boat where the water behind the boat is almost totally undisturbed. The angle on the transom is a problem. I think a permenent fix will be to replace the transom with a longer one without such a sharp angle, maybe one of those short center tube transoms.

 

I still havn't figured out why this boat runs with the bow so low. Two similar workboats I use run with the bow up a bit more and that ride can be adjusted with the motor trim, just like you'd expect.

Highlighted
Admiral
Posts: 8,571
Registered: ‎07-14-2011

Re: Having trouble getting traction.

Just for grins, check the pontoons for water.

 

Glad to hear that your fix helped things and that the motor is turning the correct rpm now.

 

Standard transom angle is 13 degrees plus or minus 1 degree.

 

 

 


"There is never just one thing wrong with a boat";
                    -- Travis McGee, main character in a book series by John D. McDonald 


 



***************

The factory recommends that a properly trained technician service your Johnson or Evinrude outboard motor. Should you elect to perform repairs yourself, use caution, common sense, and observe safety procedures in the vicinity of flammable liquids, around moving parts, near high-temperature components, and working with electrical or ignition systems.

The information offered here is only general in nature and should not be construed as complete factory approved procedures, techniques, or specifications. Always use the proper service manual for your motor, up-to-date service literature, the correct tools, and have an understanding of how to proceed with troubleshooting and repair methods. If you are unsure or uncomfortable with a procedure, a situation, or a technique, enlist the services of a factory trained technician.


Highlighted
Skipper
Posts: 11
Registered: ‎11-03-2014

Re: Having trouble getting traction.

I should have been more clear about which transom angle I was referring to, it is the bottom of the transom, not the back.

 

This transom has lifting fins along the sides, I'm beginning to suspect these are pushing the back of the boat up and driving the bow down.

 

We open the pontoons after each use to drain any water. Besides the obvious reasons for this, it also reduces the chance of spreading invasive species.