2 stroke Vs 4 stroke questions

[Kram71]

I'm currently running a 1989 Johnson V4 115hp outboard that is having some issues, and I'm weighing up the option to repower the boat with a newer used outboard. The boat is an early 80's 17.5' fibreglass half cab and has a max hp rating of 140hp.

As a new outboard is way, way out of my budget range, I'm considering looking for a decent mid to late 2000's model, and really don't know whether to go 2 or 4 stroke.

Some questions for those in the know:

• Would I need to go with the same sort of HP on a newer motor, IE would a newer 4 stroke of say 90HP be up to the task or am I better to stick with a similar HP rating?

• Weight... how does the weight of a newer 4 stroke compare to the weight of a 25 year old 2 stroke?

I'd really like to go with something quieter, better on fuel and less stinky and smokey than the old Johnson, and for this reason the 4 stroke option sounds more appealing, but really don't know which way to go.

Any thoughts or suggestions would be appreciated. Any other pros and cons between the two.

Cheers
Mark

[Skusto]

Weight will be your biggest killer of a 4 stroke, 4 strokes weren't around when your boat was built so they were never built to hold the extra weight of a four stroke.

for example I know of someone who went from a 2stroke 150 old evinrude to a new 4 stroke 150 on a old hull like yours and will not go through bars anymore.

So before you outlay all your hard earned do a bit of research and ask around on your hull if anyone has put a 4 stroke on, if the answers come back not to good then stay with the lighter 2 strokes.

Research is going to be the best thing for you.

[Giffo65]

I have a 130 Honda on a 570 Cruisecraft of 1985 vintage.This hull is rated to 175 hp, love the 4 strokes, biggest problem is ,trying to start it when it is already going ! To bloody quiet !

[Triple]

Not mine but just saw this - http://www.ebay.com.au/itm/Honda-4-Stroke-135hp-2005-Model-Outboard-Motor-/231178575833?pt=AU_Boat_Parts_Accessories&hash=ite m35d3511fd9&_uhb=1

[Almako]

Without any supporting info, I would imagine you would get a better deal on a direct injection 2 stroke than a 4 stroke. They are lighter which might suit you and they don't blow smoke either.

BTW what is your budget ?

[SHOOTER1]

Merc Opti 115 and Etec about 170kg Yamaha 4 stroke about 175kg your Johno about 140kg. Not much in it between 4 and 2 stroke but an extra 30 odd kg to what you are running currently, Suggest fill a 40-50ltr esky with water and put it right at the back and check how the hull handles the extra weight. Just a very rough guide but hope it helps. Also remember sometimes you can step up in engine size but weight is the same.

[Crocodile]

Hello Kram71

we would all like something quieter, better on fuel and less stinky.!

I think that you may be disappointed with a 90, the 115 is a de-rated 140 and is a far more powerful motor than any 90.
Finding a good second hand four stroke will be hard and expensive because they are very scare and in demand.
Is your 115 a self-mixer or a pre-mix, self-mixers use very little oil and make very little smoke/smell.

Here's a tough one, if you have an older boat, you may be over-capitalising by fitting a very expensive newer motor.

IMHO a good second hand self-mixing two stroke is the way for you to go.

[Scalem]

Just booking my F115 Yammy in for a service the guys told me Yamaha have just released the upgrade F115 which is lighter than mine, but more displacement ( 1.8 Litre) Can read about it http://www.yamahaoutboards.com/f115

I know what you are saying about the weight factor, but I did a bit of research for you... Your motor weighs 145KG, the new Yammy comes in at 171Kg, that's a difference of a mere 26Kg. Considering the displacement, the rev range of this new model .... you would think all your Christmas's have come at once. My motor is fine through south passage bar and is the '09 model. An upgrade would be very noticeable but like you I can't afford that. Just saying... to compare old 2 banger to new 4S the gap is narrowing.

Scalem

[Chimo]

You can use more better TCW3 oil that is not nearly as stinky. Perhaps your bigger issue is the need for a quality OMC Bombardier marine tech to sort out you existing motor or if that cannot be done at least you wont waste $ on a repair.

Newer 2 stroke 115HP with self oil mixing exist for 3500 to 5k so that may be an option too.

I must confess I like my old 2stroke 115s as they are a very tolerant powerful thing

Cheers
Chimo