Evinrude E-NATION, for those dedicated to water, power, fishing and fun
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Captain
Posts: 109
Registered: ‎09-12-2016

Re: Motor height and RPM's

[ Edited ]

I have no idea, you mentioned it, Evinrude service bulletin No. 2017-05(D) .

 

And furthermore the most serious issue is overpropping. Setting up an engine to go 5400 wrt 5200 when the full throttle operating range into 5500 is fine, it may cost a bit of fuel, not much.

 

The OP dealer propped the boat to 5400 and said it was fine. How is somone buying an engine suppost to know anything if they have to search the internet to find operating information. It's just pathetic.

Admiral
Posts: 6,333
Registered: ‎07-14-2011

Re: Motor height and RPM's


muskiemouth wrote:

I have no idea, you mentioned it, Evinrude service bulletin No. 2017-05(D) .

 

And furthermore the most serious issue is overpropping. Setting up an engine to go 5400 wrt 5200 when the full throttle operating range into 5500 is fine, it may cost a bit of fuel, not much.

 

I


OK, that is not a "special bulletin" it is a pre-delivery bulletin that gives rpm ranges for recent production motors by model number, not by year. 

 

It states that the 90HP has an operating range from 5000 to 5500 rpm and that the optimal propping range is 5000 to 5200 rpm. In my experience, propping the 90 HP for 5200 gives the best of both worlds, performance and economy, just as the factory recommends.

 

 

 


"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.


Captain
Posts: 109
Registered: ‎09-12-2016

Re: Motor height and RPM's

The OP's dealer didn't read it or thought it was un-important.

That sort of information should be in the engine specification on the web page and in the owners manual.

 

I didn't really mean special, just a service bulletin.

 

I think once the OP raises his motor he could be >5500 RPM and will probably need a new prop, if that wan't the case I pesonally wouldn't waste money on a prop to lower from 5375 -> 5200 RPM.

Skipper
Posts: 13
Registered: ‎04-04-2017

Re: Motor height and RPM's

 

OK, now that I have a game plan...   

 

I hooked up EV Diag last night and the new recorded high is now 5518 (only a few seconds while playing with trim), so I can assume that raising will definetly put me over.

 

Any thoughts as to which prop I might want to look into first?   Currently running a 13.2 x19".

 

Thanks

Captain
Posts: 109
Registered: ‎09-12-2016

Re: Motor height and RPM's

If go for 21 inch, that will drop you 400 rpm assuming its the same prop. 

Skipper
Posts: 13
Registered: ‎04-04-2017

Re: Motor height and RPM's

E-mail to my dealer....
 
""I've been in contact with Evinrude....  they told me that there is a service bulletin recommending a WOT RPM of 5000 - 5200 and that I should target closer to 5200.  
 
Do you have that bulletin?   No. 2017-05(D)
 
According to Evinrude (I sent them the video) they recommend raising the motor at least 1 hole (I would think 3/4" wouldn't effect the water intake) and retest, but likely will put the RPM over 5500 (I'm now seeing 5400+ on smooth water and top MPH). Assuming that is the case....  I would want to re-prop the motor to the correct target.  I'm currently running a 13.2 x 19 aluminum....  but unsure of which direction to start in selecting a prop.
 
I would like recommendations in aluminum and stainless (part numbers so I can research a bit).... and I understand that this is all an educated guess as the final result is what I get on the water. 
 
Your help is appreciated!""
 
His response...
 
""We can try raising the motor and reducing pitch to a 17""
 
Smiley Frustrated  
Captain
Posts: 109
Registered: ‎09-12-2016

Re: Motor height and RPM's

[ Edited ]

I think its time for another dealer. You would gain 600 rpm if you did that. I'd try a 21 inch Viper if you're going stainless.

 

You also want to make that you're proping this boat with a typical load. Ill re-iterate, going under that range can cause engine damage going above but < 5500 might loose some efficiency. I would error on the side of being over.

Skipper
Posts: 13
Registered: ‎04-04-2017

Re: Motor height and RPM's

 

How does prop diameter play into this....  can I go from a 13.2 to say a 13.9?

Captain
Posts: 109
Registered: ‎09-12-2016

Re: Motor height and RPM's

The larger the diameter the bigger the drag is, so generally you will lose rpm. It this case its not that significant IMHO. 

Admiral
Posts: 6,333
Registered: ‎07-14-2011

Re: Motor height and RPM's

Hrdrokn,

Check your personal mailbox for a message.

 

Click on the small envelope icon near the top right of the page, just above the HELP  tab.

 

 

 


"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.