Are Yami's wannabe Kawi's

[X2guy]

Been wondering this for a while now. All the modded yami motors seem to be trying to be like the kawi.
1. 6mm strokers
2. Flat top kawi pistons
3. Welding on kawi intakes to run kawi reeds
4. kawi couplers
Be a lot less work to drop a kawi in those superjets:scared:

 

[D-Roc]

too bad the yami motor makes more power vs the kawi when comparing displacement. also i thing if you do a 6mm yami motor with bigger reeds and flattops it will make more power that the kawi stock.

 

[Waternut]

This should help answer your questions... After seeing people doing tons of mods based on the kawi engine (reeds, stroker, more displacement, flat top pistons, etc.), I finally asked why kawi engines produced roughly the power same as the SJ motor.

http://www.x-h2o.com/threads/62731

 

[X2guy]

too bad the yami motor makes more power vs the kawi when comparing displacement. also i thing if you do a 6mm yami motor with bigger reeds and flattops it will make more power that the kawi stock.

Of course...But everyone who does a 6mm engine always fixes up the crappy mismatched ports of the yamaha. If you left the ports alone and were able to keep the same stock port timing would it be better?

When my 800 was running tops it would rip my arms off. I should have taken your ski for a ride in wasaga to compare D-roc

 

[D-Roc]

yes you should have. a kawi needs 800cc to make 79hp i believe, the yamaha needs 701cc to make 72. how much power would a 800cc yamaha make? if i did my math correct then a yamaha could produce 79hp with 776cc. not that hp numbers mean anything. i am not sure why chuck uses the kawi reed cages vs the boysen or deltas but i would think it is because they are bigger and would flow more. i don't know really. kawi has some better things then yamaha for sure. displacement, ignition, flywheel/stator setup. if yamaha did that instead of trying to make the superjet handle like an sxr i would consider buying a late model superjet. hey that another thing to add to the list, lol

 

[Waternut]

Well from I understood about the kawi ports was they are basically 90° angles causing a really bad turbulent flow instead of a nice smooth laminar flow from the 701 cylinders. I could be wrong there but that's the way I saw it. I've looked all over both cylinders but can't remember what the transfer ports looked like.

 

[D-Roc]

transfer ports look like ports that transfer.

 

[WFO Speedracer]

I don't see a lot of difference in the transfer port areas,angles or heights

 

[junkyardj]

my 61x 85.5 flat top is bang on with ports on your x2 doug i think your onto something here hmmm where would they both be at for torque bill ny?

 

[X2guy]

transfer ports look like ports that transfer.

You drinkin D-roc?:beerchug:

 

[X2guy]

yes you should have. a kawi needs 800cc to make 79hp i believe, the yamaha needs 701cc to make 72. how much power would a 800cc yamaha make? if i did my math correct then a yamaha could produce 79hp with 776cc. not that hp numbers mean anything. i am not sure why chuck uses the kawi reed cages vs the boysen or deltas but i would think it is because they are bigger and would flow more. i don't know really. kawi has some better things then yamaha for sure. displacement, ignition, flywheel/stator setup. if yamaha did that instead of trying to make the superjet handle like an sxr i would consider buying a late model superjet. hey that another thing to add to the list, lol

Well the SXR is really only 782cc's

 

[D-Roc]

no, just thought i would share some insight. drinking at home while on the X? no, thats not my style, lol.

well that throws my math out.

 

[D-Roc]

is it rated for 79 or 80hp?

 

[CARBONX2]

Big difference on port angle and sizing, with the right porting the kawi kicks butt, but very few people put the time in, Steve Webster being one of the few showing what can be done.
The current pipes for kawi's smother them, hence the racers preference for an adapter plate and yami pipe.

 

[AdamOntario]

Well the SXR is really only 782cc's

and a 701 is 73 hp

 

[WaveDemon]

last time I checked the yamaha 800 made 120 hp stock.

 

[SXRguyinMA]

last time I checked the yamaha 800 made 120 hp stock.

are you on crack? :chairshot:

right from Kawi:

The high-performance JET SKI 800 SX-R is powered by a twin-cylinder, 782cc two stroke engine and produces the most horsepower available in a production stand-up JET SKI watercraft. It is fed by a pair of 40mm Mikuni carburetors and features a waterproof and maintenance-free Capacitor Discharge Ignition (CDI) system with digital advance. Aggressive exhaust port timing and a large-diameter exhaust pipe help provide superior top-end power while a water-jacket surrounding the exhaust pipe helps to reduce underhood temperatures and suppress noise.

SJ-> :chairshot: <-SXR :biggthumpup:

the yamaha needs 701cc to make 72. how much power would a 800cc yamaha make? if i did my math correct then a yamaha could produce 79hp with 776cc

its 781cc and rated for 80hp, so according to your figuring, with 5cc extra they make 8hp more

 

[Matt_E]

are you on crack?

What are you talking about? GP800 motor makes 120HP stock.

 

[ADDict]

:deadhorse:
We all know the answer.. The only reason this gets brought up is that some people can't deal with change. If they are so much better, then why in the hell don't we see them all over the place? Wait, maybe it's because the suck ass...
You can argue it all day that you can get more power, blah f'in blah.. It's BS. I've had kawis, and yamahas.. In fact I've had both kawasaki power, and yamaha power, in the same hull with the same bolt ons. For free ride, yamaha hands down. Please stop wasting server space for this nonsense! I hear they have tons of room for it here.

 

[SXRguyinMA]

yamaha sucks