4 stroke + H2o, can we get along???

[yamaslut]

A question Tim asked in the Watcon thread got me thinking...

Is the 4 stroke a viable option for surf???

Could it be made to be?
What really happens if it's sunk?
Are parts automaticly ruined??
What would it take to clear a sunk 4 stoke?

I have only heard horror stories and have no experience in this at all.
I would like to hear from people who really know from experience, since
this will be part of our future... at least fro the racers...

 

[the only couch rider]

you are looking at a good 3-4 oil changes to clear the water out of the motor at least... i know of a few four strokes in myrtle beach that had to do more than that after water ingestion. the parts were not trashed but still a pain to have to change the oil to make sure you get all the water out

i have what looks to be a water ingestion failure on my 250x and that thing need a complete rebuild after it hucked a rod through the cases. full motor replacement.

i think the 4 stroke is viable for racing and the rec rider, but not for free riding and freestyle for the simple fact of the abuse and submersion the motor would be faced with on an on going basis

 

[yamaslut]

will water always get in the oil sump??? I thought it was sealed off from the upper

 

[Idok]

Ok....at risk, i will admit to sinking a 4 stroke in the near past....not just wetting the plugs, Im talking engine FULL of water..


was able to get it running within a few minutes.....ran about 2-3 gallons of oil thru it and its fine now....


granted, this was fresh, not saltwater....

 

[WaveDemon]

good idea to make it's own post nick. and like you are alluding to if it can be made injestion resistant wouldnt' the torque of a 4 stroke be a good thing?

 

[yamaslut]

I know 4 strokes create much more torque than 2's

 

[yamaslut]

what about the valves and cams????

 

[WFO Speedracer]

you are looking at a good 3-4 oil changes to clear the water out of the motor at least... i know of a few four strokes in myrtle beach that had to do more than that after water ingestion. the parts were not trashed but still a pain to have to change the oil to make sure you get all the water out

i have what looks to be a water ingestion failure on my 250x and that thing need a complete rebuild after it hucked a rod through the cases. full motor replacement.

i think the 4 stroke is viable for racing and the rec rider, but not for free riding and freestyle for the simple fact of the abuse and submersion the motor would be faced with on an on going basis

Newer generation Kawi four bangers have always had weak bottom ends including the motorcycle engine that the 250x was based on,I worked at the stealership a while back,I can't count the number of bottom ends we replaced under warranty on the big sport bikes.I think that first off you would make the air intake into the handlepole with a maze of water seperating channels before it got to the actual air intake of the engine,that would be the first step in the water ingestion nightmare.Then maybe a water sensor in the air intake tract with a trap door to let air in and water escape.

 

[Idok]

most of the power in a 4 comes from the head. valves/cam/head porting would be the new big thing for us.. swapping cams.. getting bigger valves, better spring, porting the head, hi-compression pistons, etc would be the common first mods i'd imagine.

so youre saying basically you follow the MX bike mod path......right?

 

[vitaly]

A question Tim asked in the Watcon thread got me thinking...

Is the 4 stroke a viable option for surf???

Could it be made to be?
What really happens if it's sunk?
Are parts automaticly ruined??
What would it take to clear a sunk 4 stoke?

I have only heard horror stories and have no experience in this at all.
I would like to hear from people who really know from experience, since
this will be part of our future... at least fro the racers...

I've seen a couple of sunken Kawi STX-15F (the infamous cooling hose problem).
One was fine, the other one got water in oil and needed a couple of oil changes. No problems after that.

A Honda R-12X gets pretty decent air in the surf, can take a lot of beating and does not sink... :wave:

So, IMO, yes, a freestyle/surf 4-stroke ski is very feasible and a very close reality.

 

[vitaly]

the parts were not trashed but still a pain to have to change the oil to make sure you get all the water out

You can still have some traces of water in the oil, no biggie, the water will eventually evaporate from oil, does not diminish the oil lubrication qualities that much. The salt that left is going to end up in the oil filter if it crystallizes.

 

[vitaly]

:dunno:

i would guess

i'm curious to see the prop sizes the 4 strokes run... i really havent looked into them at all.

if it's an EFI system, then there's another huge source of gains... both from timing and fuel map changes..

the mx bikes are just starting to go into EFI now in '08/'09

green hulk guys can probably write up something real nice for us in this thread.

ALL 4-stroke couches and HS are EFI.

 

[WFO Speedracer]

The only problem with modding four strokes is when you star changing cams and porting the power band becomes much peakier very much like a two stroke,on the Weber engines most of the performance upgrades are done through fuel mapping and timing which pretty much maintains the wide power band.

 

[Mark44]

p

i can just see beach patrol/regular people freaking out once they see 8-10 of us doing oil changes right there on the beach...

they're gonna miss the 2 strokes then​

. :haha:

LOL so true!

Mark44

 

[WFO Speedracer]

i can just see beach patrol/regular people freaking out once they see 8-10 of us doing oil changes right there on the beach...

they're gonna miss the 2 strokes then. :haha:

I am thinking it will have to go back on the truck for the oil change sessions.:wiggle:

 

[vitaly]

i can just see beach patrol/regular people freaking out once they see 8-10 of us doing oil changes right there on the beach...

they're gonna miss the 2 strokes then. :haha:

The ability to simply drain oil like from a bike or a quad would be priceless.
My quad riding buddies do a few of oil changes per day, takes them a few minutes each.

 

[Mark44]

o

I am thinking it will have to go back on the truck for the oil change sessions.:wiggle:

O just dig a hole in the sand.

Mark44

 

[WFO Speedracer]

Why they don't run a drain hose setup like they do on the Ski Nautiques and Mastercrafts is beyond me.its just a hose with a swivel,attached to the drain hole in the oil pan,you run it out the dran plug,uncap the end and drain the oil.The oem's don't do this because they don't want you changing your own oil.

 

[WaveDemon]

will water always get in the oil sump??? I thought it was sealed off from the upper

water will probalby always get in the sump if it makes it to the cylinders. the piston rings don't seal completely.

 

[vitaly]

Why they don't run a drain hose setup like they do on the Ski Nautiques and Mastercrafts is beyond me.its just a hose with a swivel,attached to the drain hole in the oil pan,you run it out the dran plug,uncap the end and drain the oil.The oem's don't do this because they don't want you changing your own oil.

Some oil will still be trapped in the sump.

Edit: on the other hand it could be two hoses....