2 stroke comeback.

[Jeff B]

To do my bit for recycling I decided to recycle this old Yamaha 2 stroke outboard that nobody wanted.
Was pretty heavy but once leg/prop removed the actual engine is under 80kg.
First job is make new intake manifold.

[Jeff B]

Only 2x seized bolts removing leg, pretty good. Biffed that in scrap pile.
Briefly looked at doing bevel gearbox but then I would just have a sportjet nd they stick up a mile high and the gearbox robs power.
Nup, this is going conventional.
Exhaust copied outboard sort of but with performance enhancements..

[Jeff B]

Carbs stacked in a row, made linkages up to adjust. Works well.

[Jeff B]

Spline in crankshaft is same as jetski driveshaft (pretty handy aye!) 22mm so a polaris driveshaft flipped 180 deg plugs into engine and Kawasaki impeller (20mm spline)
Like it was meant to be.

[Jeff B]

Bit of a guessing game with pump but it's getting a 158mm 2 stage with angry 21 deg front, angry 4 blade 24 deg rear.
We call this the "hyper pump" to tame the mighty 2 stroke torque.

[Jeff B]

Makes for a very light, compact setup.
Engine with everything on it running is 96kg
Pump is 26kg + grill (3kg) and bucket (3kg)
Short, 800mm transom to front of engine and low, 500mm total height as there are no camshafts or valves up top.
Similar dimensions as my tipped over L15 honda but with 100hp more.
And I'm guessing about 3x the fuel usage....

[Jimmy Jet]

Awesome Jeff. I harboured dreams of doing similar but with the V8 300hp OMC but they are really hard to get now.
How do you deal with alignment/flex in the driveline? I didnt pick a coupling in there?
How many HP?

[Jeff B]

The splines on driveshaft are ever so slightly curved, this allows for a bit if movement. Alignment still needs to be spot on or the splines will chew out.
Polaris and Seado jetskis are set up like this factory. It's a floating driveshaft

I know of a OMC v8 just down the road getting the same treatment...

[Jimmy Jet]

Sweet yep did wonder that, a few things are set up similar. Nice and easy.
Cool! Hopefully they are on the forum and share the love. 2stroke,V8,lightweight. Whats not to like? Fuel use....

[steelo]

Do you do factory tours?

[lachlan]

Approved

[Jeff B]

No tours here, too many health and safety hazards.
Plus I keep all my top secret projects in the back of the shed.
Had a Southern jet trim nozzle that I modified the cone entry on and made new insert, will start at 80.5 and go bigger from there.

[Warwick Marflitt]

If Jeff was a Vet He'd make Pigs Fly backwards...... Once again you fabricate Amazing dreams in a Health n Safety free zone.......
                                 


                                         

[Jeff B]

https://youtu.be/zkRhbpJitEI

She is a runner.
Now to build a hull to match...

[Jimmy Jet]

Mean. Its going to be one of the best sounding 2 strokes on the water.