Joe and Chris Grace's seadoo spark powered Krash Footrocket

[speedysprocket]

Direct injecting a two stroke is going to be the only way to get its efficiency close to a four stroke's. Otherwise, you're going to have unburnt fuel blown right through the cylinder and out the exhaust before combustion occurs, and thus some of that energy you put into the engine is not giving you any of that energy output we want. I do agree, though, that there are more mechanical losses of energy in a four stroke due to the extra components that have to be driven by the crank.

 

[davidescu_radu]

4 stroke stand-ups would be much better to ride if they would place that heavy engine more backwards, and also they need a drain plug on the bottom of the intake manifold for the water ingesture situations(in surf) - plus a quick and easy oil drain system

 

[j0hnny]

oil drain has to be like we do in boate. you have an access port you hook a pump up to at the lowest point in the pan. makes oil changes effortless

 

[OCD Solutions]

The intake comes off the spark engine very easily giving full access to suck out the oil via the intake duct. Chris happened to have the intake off when i asked that exact question so it was pretty easy to demonstrate what it would take. In addition to a couple oil changes afterwards, we also discussed the possibility of adding some sort of an oil catch can/filter that could trap and hold any residual moisture that might remain as it evaporates at temp.

 

[davidescu_radu]

Those 3 have 4 stroke engine inside - what do you think?

 

[bird]

it's not about when, they already do folks
EFFICIENCY is for @Matt_E
https://www.youtube.com/watch?x-yt-cl=85114404&v=QuxinZMSetc&x-yt-ts=1422579428#t=30

 

[zimmy]

Those 3 have 4 stroke engine inside - what do you think?

I think I would want a removable plate on the underside of the hull to find any bolts that I might drop in there when working on that.

 

[vomitspot]

i would like to see a build page as i have a spark donor and sxr/sj

 

[mmprestine]

Ya they said the same thing in the snomobiles too, 4-strokes came and went. I'd like to see one of the snowmobile 800 etec's in a ski!

 

[sneds]

^x2 It would be nice if BRP introduced a high performance version of the spark with the 800 etec in it. That would be a pretty fun sitdown!