Logo

TE40ELETB 40 hp Evinrude Proper prop selection and max RPM recommended

Ferrarimx5

New member
This is what I have:
a 1993 Evinrude 40HP twin
on a 1993 Bass tracker TX-17
31 MPH @ 5200 RPM with 17 pitch Prop (GPS)
31 MPH @ 5800 RPM with 15" Prop (GPS)

Recommended RPM range is 4,500 to 5,500 RPM for the 40HP <-- I have the 40 hp

Here is my question:
Since this is the lowest horse power rating for the 737 CC family of Evinrude engines (40, 48, 50, 60 HP) and the rpm range of the 60 appears to top out at 6,000 rpm, am I hurting this engine by running the 15" Pitch at 5,800 WOT?
I tend to run WOT about 30 percent of the time and only about 80 percent of WOT for most other adventures. (4,500 rpm)

I fish..
But I also like to skip across the water..

I like the 15" pitch, but am worried I might possibly be over-revving.
(It is also interesting to note that I might actually be gaining 1 MPH at times with the 17" Pitch, but only occasionally and only when I have it trimmed just right). (GPS)
If the 60 HP Evinrude 737cc motor has basically the same parts (Pistons, Rings, Head) as the 40, then is it safe to figure this 40 HP motor can spin like its more powerfully tuned, same size brother?

Some have suggested that running at this higher RPM is actually easier on the 40 HP motor than running the higher pitch at 5,000rpm

Your opinions will help me greatly.

Thank you in advance...
 
Last edited:
Here is another way to view this question.

Is there an Evinrude site that gives the specs (i.e. RPM's) for the 737cc family of outboards?
Also, the differences between the 40hp, 48 special, 50hp, 55hp and the 60hp?

I know the carbs are jetted differently and possibly the brain (Computer), but what other differences are there that give each step up in model its extra hp?

I am assuming that there should be no problem running this 40hp engine at 6,000rpm if that is where the 60 HP makes its best hp...

Basically the same question, just adding a request for redirection to a chart of some kind or to another area where I can raise my education level.
 
i personaly would stick with the 15 pitch.
all you have to do is wind in the throttle stop a touch to get it down to 5500 max and it will be fine.
the 15 pitch is less strain on the engine and will give better hole shot and probably save the engine a fair bit.
fuel consumption will be lower than the 17 struggling to reach max revs.

by dropping 300 revs youl lose around 2mp top end, this is not much and could save you a lot of money on fuel and
spare parts when the engine goes bang.
the 60hp model has different carbs and just breaths better all round, but the 60hp model also dont last as long as the 40hp model
if kept at correct revs.
This is why omc made a much bigger 60hp engine with another cylinder and a lot more cubic capacity.
a 3 cylinder 60hp not only delivers the power better from the begining, but again will outlast the 2 cylinder engine (in theory).

i would just make sure you dont go over the recommended 5500 rpm,youl probably find your actualy producing the max power at around 5400rpm.
 
Awesome, this is the kind of answer I was looking for..
5500 RPM will allow me to run hard enough (29-30 MPH) and saving gas is always a good thing.
Hole shots are quick and easy with the 15.
Seems like the engine really likes the prop and it spins to 5,800 with ease..
I can not wait to load it up with four people and an extra bit of gear!!!
 
Last edited:
you might find that you need to either go down another prop with 4 people or drill the prop for holeshots.
if you find the top speed is good with the 15 but the pull away with 4 people aint much good, you simply drill a
hole between each blade to let it vent and spin up on take off.
this aint a gimic it realy works.
you cant do any harm unless you went mental and put a huge hole ha ha .
i just use around 1/4 inch to 3/8ths size drill and find thats plenty.
start with just a 1/8th and try it then go up in stages and make sure you do timed pull aways.
it lets a prop pull up a much heavier load without having to go down and suffer top end.

i done it on a mercury prop and couldnt believe the benefit for pull away,once up on plane its back to normal and
sort of closes itself once revving.

if you look at a lot of expensive stainless props they come with the venting in them,its just not normaly done to the alloy props
but it works just the same.


Here below is a few pics of a prop i used on a mercury 60, this once drilled gave blistering pull away with
a 42mph top end.
before drilling it no way could i get it to plane with 4 people onboard a 15ft dory,it wasnt easy with just me.
it looks rough in pics due to me scraping the paint off this old prop and getting it ready for a re-spray to
make sure no burning took place on pull aways etc.
it dont it just does what its meant to, ventilate and let the prop spin upto speed and let engine produce its full power.
.48-73140 15  1025x15 merc 50 70.jpgDSCF6466.jpgDSCF6467.jpgDSCF6469.jpg

its something you might want to think about for the 17 pitch with a bit of weight onboard.
save losing top end and just gains pull away.


i might be doing this to a 19 pitch stainless very soon


phill
 
Back
Top