Evinrude upgrade

[Hadenough]

I have a 5HP 2 stroke 2 cylinder outboard, old but in in good condition. Model number is BE5DREIA and from a previous post thanks to VicS I know that this translates to:

B= made in Belgium
E= Evinrude
5 = 5hp
DR = derated, rope start
E = 9, I = 1 ( hence '91)
A is a production suffix

I need a bit more umph for a new tender we've just acquired and the D for derated bit of the model number got me thinking. I know you can increase the output of 9HP to 15HP by changing the carb / jets. Does anyone know if this possible with the 5HP up to say 8 or 9HP?

 

[GrumpyOldGit]

Probably find that the exhaust port would need machining out , carb/jets changing, oversizing the bore/ piston and raising compression ratio (could be a bit too much to pull on recoil starter) unless also convert to electric start in which case you will have exceeded the original engine value several times, failing that, I would offer you 20 quid to take it off your hands !!

 

[VicS]

I suspect its a derated 6hp but I dont know how its derated.

all the parts lists available on line only cover the American models and dont include this 5 hp version

If you could find out how its derated you'd probably be able to uprate it to 6Hp but that may not worth the effort.

The 8 hp is a similar engine but the crankcase, as well as carb jets, is different to the 6 hp ... I've looked into the possibility of uprating my 6hp to 8hp. Not impossible but not really a viable option.

The 9.9 and 15 hp engines are a larger cubic capacity so different animals.

Worth perhaps contacting Oakley Marine in Brighton. If anyone knows if uprating it is an option I would think they will.


Check that the throttle valve fully opens when you turn the throttle to max
Its just possible that somewhere in the linkages there is a limiter that restricts it. If so and that can be removed you might at least get 6 hp out of it

 

[Hadenough]

VicS

Many thanks again. As you say probably not viable but I'll make some enquiries and update if I have any success.

 

[Lakesailor]

Not the same thing at all but the Mariner/Mercury/Tohatsu 4,5 6hp motors are all the same with different carbs. Trouble is the carbs are nearly £300.
Much better to just sell the motor and get a bigger one.