Economical old 2 stroke

[darklordhill]

Evening all

I'm looking to replace the 1995 yamaha 115 v4 on my ribtec 535.

I would like as many opinions as poss for what you consider to be the most economical 1980s /1990s 65hp - 90hp 2 stroke outboard ?

Thanks in advance.

[beamishken]

85/90 yamaha we once traded up to a 115 20 odd years ago & didn't know how quick to trade back down to another 85 when we realised How thirsty the v4 was compared to the 3 cylinder
You might find something more economical than an 85/ 90 yam but you won't find a better engine

[darklordhill]

Originally Posted by beamishken

85/90 yamaha we once traded up to a 115 20 odd years ago & didn't know how quick to trade back down to another 85 when we realised How thirsty the v4 was compared to the 3 cylinder
You might find something more economical than an 85/ 90 yam but you won't find a better engine

Everything is pointing toward the yam 90, Is it much more efficient than the 115 ?

[Pikey Dave]

"economical" "old" & "2 Stroke" ain't words that often crop up in the same sentence.

[paddlers]

I had a Yamaha 85 hp for a couple of years. Ran like a sewing machine and to be fair I never thought it was that thirsty....!

The 135 Mariner I'm running now is THIRSTY, especially on full chat but I love the noise.

[Ribochet]

Originally Posted by Pikey Dave

"economical" "old" & "2 Stroke" ain't words that often crop up in the same sentence.

Damn you beat me to it - my sentiments exactly

[cptsideways]

Our late 90's Mercury 3cyl 90hp always seemed quite good on fuel. Certainly in comparison to our current 5.7L V8 its certainly no worse! Not sure if thats a good thing though

[whisper]

Yam 90 2 stroke Probably the best old 2 stoke for power to weight ratio and reliability

[beamishken]

Originally Posted by Pikey Dave

"economical" "old" & "2 Stroke" ain't words that often crop up in the same sentence.

Yep your right but it's relative a 3 cylinder yam next to a v4 is frugal by comparison

[darklordhill]

Thanks for all the advice,
So are you saying that the Yam 90 is a better engine than the yam 115 but with no improvement on the fuel efficiency.
If so I should maybe be looking for something smaller, I have been offered a 90s Mariner 75hp and a 90s Suzuki 65hp.
Are either of these likely to be more efficient ?

[C-NUMB]

The yam 90 is surprisingly "economical" considering its a carbed 2 stroke. The WOT consumption, low to mid thirties l/h is not far off compared to modern engines
(off course the difference is there at lower speeds).

Power to consumption wise, possible its one of the best designed old style 2 stroke outboards ever made, cant recalling test figures of any other outboard as good.

Economical is maybe not the correct word but in its league its very good.

[two stroke mick]

you should bear in mind there is more costs to running an OBM than filling it with petrol, keep an eye on the cost of keeping it running

TSM

[HDAV]

I love 2 strokes but if i was spending money then it would be on a proven reliable 4 stroke with low hours and good maintenance record. There is a lifespan to all things mechanical and 20+ year old motors are not in the first flush of youth.

The Etec type motors are supposed to be very good on fuel, it depends on usage, your dropping HP (alright your 115 is probably closer to 100 now but an older 75 may be at 60 or less) and you might find your running higher revs to compensate, less torque, smaller prop etc. Higher revs burns more fuel so unless your current motor has blown something big and expensive then your spending money to save ??? if your looking at a straight swap then you might save some fuel but is it worth the faff?

http://www.evinrude.com/en-gb/engine...etec_90_inline

http://www.suzuki-marine.co.uk/docs/...an%20Burn).pdf

[Dunky75]

I have a 1989 3 cyl mercury 80 & cruising at 4000 rpm, 24kts with some WOT bursts I average 1.35 nm per litre.

[Bushrider]

Originally Posted by C-NUMB

The yam 90 is surprisingly "economical" considering its a carbed 2 stroke. The WOT consumption, low to mid thirties l/h is not far off compared to modern engines
.

Had the 90 Yam on my Searider and used 0.5l/km .
On the same boat I installed later an ETEC 90 - some of you may be remember the boat from the Round Ireland - where I used with the ETEC 0.44l/km .
So I would consider the Yam 90 as quite economical .
For the difference to a more expensive motor you can pay for a long time your fuel bills .
The problem with the Yam 90 - it is harder and harder to find a good one ..

BTW - my Yam F100 4 stroke uses on another boat also exactly 0.5l/km ...

[darklordhill]

So the yam 90 is economical compared to the yam 115 but old and hard to find a good one.

That helps as the chap I bought the rib from has offered me the yam 90 that was originally on the boat, it had broken so he he gave it to somebody to rebuild and its nearly ready. I suppose its worth taking a chance if the price is right.

Also the rib is only rated to a 90hp and as somebody said there could be problems with insurance if i leave the 115 on.

Thanks everyone