Are Yami's wannabe Kawi's

[SXRguyinMA]

their sleds have only gotten worse since they stopped usin suzi engines lol

 

[Matt_E]

tigersharks used suzuki engines

So did Wetbikes, no?

 

[the WaTeRhAwK]

the only reliability mine had in 100+ hrs of hard riding was me ingesting water and bending a rod.

Yamaha sucks ass, kawi rules, and for s and giggles suzuki's the best

let the fun begin

I've heard that kawi 650 cranks, and late '80's-early'90 suzuki twin streetbike cranks, are the same thing. also, kawasaki and suzuki share the same manufacturing plant.

 

[X2guy]

enough with the pwctoday quality info...easy question. No one has really answered why people modify the yamaha motor to be like the kawi.

 

[Matt_E]

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:

To answer the questions:

1. Strokers make more power. That goes for any engine. It's not emulating Kawi per say.
2. Flat top pistons - they bring the port timing down further. Nothing Kawi specific, the pistons just fit the purpose.
3. Larger intakes, more power.
4. Kawi couplers - yup, they're better.

 

[tnj4life]

Ive ridden and owned both. Stock for stock the yamahas are just more fun, they are better for freestyle and tricks. Obviously you would choose which one is better for your riding preference, why would you pick a motor thats going to be the opposite of what your riding style is? As wavedemon said its much cheaper to start with a lowend torque motor and build it up as you go. Kawis do have some better designs like their couplers so why not incorporate them to a yamaha if it helps performance? Ive got a fx1 with a kawi pump and a 84 js440 thats soon to have a yamaha powerplant so you can tell I dont care about mixing parts =].

 

[tom21]

enough with the pwctoday quality info...easy question. No one has really answered why people modify the yamaha motor to be like the kawi.

actually Wavedemon did.

To answer the questions:

1. Strokers make more power. That goes for any engine. It's not emulating Kawi per say.
2. Flat top pistons - they bring the port timing down further. Nothing Kawi specific, the pistons just fit the purpose.
3. Larger intakes, more power.
4. Kawi couplers - yup, they're better.

smaller and lighter-plus its billet if you are talking about the umi- seems silly not to use a bolt on billet part over a cast one.

 

[WFO Speedracer]

are you on crack? :chairshot:

right from Kawi:



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



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

Good I will throw one in there as well Rotax 787 110 hp bone stock and it happens to be very reliable ,mods extremely well and its the winning-est engine in PWC racing history bar none ,those are the fact dispute them if you wish.

 

[Matt_E]

Seadoo/Rotax know how to make power.
RV, injection, and a real pipe = 110HP.

 

[WFO Speedracer]

Seadoo/Rotax know how to make power.
RV, injection, and a real pipe = 110HP.

Damn straight ,I estimate the engine I am putting together for the X2 to be in the 130-140 hp range and reliable.:Eyecrazy:

 

[Matt_E]

The stock porting in Rotax cylinders is some of the finest I've seen.

Yamaha ...... well....:lmao:

Yamaha pipe....well.....:lmao:

 

[WFO Speedracer]

The formula for 130-140 hp is pretty simple on a Rotax,high compression head around 180-190 lbs,replace exhaust pipe,add fuel pump to the slave carb,drill cases for another pulse fitting,port the cases,rejet the carbs,add flame arrestor and total loss ignition and voila!

 

[FX-Rex]

actually Wavedemon did.


smaller and lighter-plus its billet if you are talking about the umi- seems silly not to use a bolt on billet part over a cast one.

I'd rather blow out a coupler than a midshaft

 

[kawasakit2me]

So did Wetbikes, no?

for a time, yes they did.

I wish I did not know that.

 

[WaveDemon]

actually Wavedemon did..

thanks, I'm glad someone read my cliff notes version of yamaha vs kawi engine theory. :soapbox::biggrin:


here is an even shorter version...

the reason that made yamaha the best choice for rental shops is the same reason it's good for rec riding and freeriding.


The reason you you add kawi parts is because you want it to flow more fuel.


The reason kawi isn't a great freeride platform is because it was designed to race.

 

[Scorn800]

I like Kawasaki's :bananalama:
The SXR is nicely layed out & cake to work on. After making stand up's for 30 years they got it right. The preform great stock & can become animals when properly modded:Banane26:
This past season I rode a couple 09 sj's.:cool2:1 stock & 1 wet piped limited. They both handled much better than the old rn sj. But that's all yamaha changed. Still haven't ungraded electrical or carbs all for more money than the sxr:thumbsdown:

 

[WaveDemon]

I like Kawasaki's :bananalama:
The SXR is nicely layed out & cake to work on. After making stand up's for 30 years they got it right. The preform great stock & can become animals when properly modded:Banane26:
This past season I rode a couple 09 sj's.:cool2:1 stock & 1 wet piped limited. They both handled much better than the old rn sj. But that's all yamaha changed. Still haven't ungraded electrical or carbs all for more money than the sxr:thumbsdown:

I'll agree that the sj costs too much.

 

[#ZERO]

Yep the Yamaha transfer ports are aimed more toward the boost port opening and the roof angles are a bit steeper which gives the engine more bottom end power and fuel economy.

Porting the Kawi cylinders with similar angles will help, but they're more suited for racing then freestyle.

Keeping the roof angles steeper and the transfer ports aimed away from the exhaust port opening helps with keeping the air/fuel mixture in the cylinder at the lower rpm ranges.

 

[suva]

The SXR is nicely layed out & cake to work on

Except for battery location.

 

[FX-Rex]

Yep the Yamaha transfer ports are aimed more toward the boost port opening and the roof angles are a bit steeper which gives the engine more bottom end power and fuel economy.

Porting the Kawi cylinders with similar angles will help, but they're more suited for racing then freestyle.

Keeping the roof angles steeper and the transfer ports aimed away from the exhaust port opening helps with keeping the air/fuel mixture in the cylinder at the lower rpm ranges.

What is the source of that information?