How/why is the Yamaha pump better

[Vumad]

I've heard plenty of claims that the Yamaha pump is better than the kawi pump. People discussing conversions often claim the kawi motor is better and the real reason Yamaha skis seem better is the pump.

Besides personal brand preferences, or preferences in how the pump installs, what makes the pump better. The only obvious difference is the diameter of the pump, but kawi guys (mostly racers) seem to stick about 142mm.

Think of the motor arguments about port timing etc, qualifiable/quantifiable differences in the pumps.

Personally, I prefer my Yamahas over my kawis because the power comes on earlier and smoother. I have not ridden a Yamaha motor with a kawi pump or a kawi motor with a Yamaha pump, but I fail to see how such performance is generated by the pump rather than the motor.

So, Why should I want a Superjet pump in my kawi? What's the facts to back up such a change?

 

[N3vrSat1sfied]

Well I have riding several yamaha engines backed with kawi pumps. 750sx with 701 and 140 pump, to emes with php898 and 155 kawi pump.
I can't really answer what the differences are. But I know there was a reason Malone preferred them over yamaha pumps when he brought his hulls to the market.

To me their are pros and cons of both. Yamaha is way more readily available while kawi is easier to assemble/install. Also no midshaft to strip out or have pushed in. Just my opinion


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[kevbo]

Well I have riding several yamaha engines backed with kawi pumps. 750sx with 701 and 140 pump, to emes with php898 and 155 kawi pump.
I can't really answer what the differences are. But I know there was a reason Malone preferred them over yamaha pumps when he brought his hulls to the market.

To me their are pros and cons of both. Yamaha is way more readily available while kawi is easier to assemble/install. Also no midshaft to strip out or have pushed in. Just my opinion


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The Yamaha pump has a little more capacity than the smaller Kawasaki unit. It allows more inlet area and lower pitch impellers for a given power. I installed a Yamaha pump in my x2. The performance difference was in hookup and holeshot.

 

[N3vrSat1sfied]

The Yamaha pump has a little more capacity than the smaller Kawasaki unit. It allows more inlet area and lower pitch impellers for a given power. I installed a Yamaha pump in my x2. The performance difference was in hookup and holeshot.

True if you are comparing oem to oem then yes yamaha is 144 while kawi is 140


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[mthomps]

I personally feel that the main reason yamaha makes a stand up and kawi does not is simply because kawi tried so many things they offered to the consumer while yamaha figured out the meal ticket and stuck with it.

The dimensions of a yamaha pump from 90 to current have not changed while kawi changed a lot and had many models. All with different parts. Meanwhile yamaha got the pump right from square one. (Im almost done building a bad ass 701 based engine on sterioids with a lot of91 superjet parts. You cant build a roided out sxr with 550 parts)

Its not just the pump becausw the engines are the same way. A 1990 crank and a 2015 crank are the same and that says a lot to a guy who likes jet skis.

Also, pound for pound a superjet destroys a kawi when it comes to torque and i feel that got the ball rolling

 

[N3vrSat1sfied]

92 started the 750sx with the same pump that went in the sxr's.


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[snowxr]

I personally feel that the main reason yamaha makes a stand up and kawi does not is simply because kawi tried so many things they offered to the consumer while yamaha figured out the meal ticket and stuck with it.

The dimensions of a yamaha pump from 90 to current have not changed while kawi changed a lot and had many models. All with different parts. Meanwhile yamaha got the pump right from square one. (Im almost done building a bad ass 701 based engine on sterioids with a lot of91 superjet parts. You cant build a roided out sxr with 550 parts)

Its not just the pump becausw the engines are the same way. A 1990 crank and a 2015 crank are the same and that says a lot to a guy who likes jet skis.

Also, pound for pound a superjet destroys a kawi when it comes to torque and i feel that got the ball rolling

You're seriously off base with your statements. Kawi has had 4 pump designs for stand ups over the past 42yrs. The sxr pump is based on the 1992 pump, which is derived from the 1986 650 pump.
Yamaha has 2 main. pump designs for stand ups over the last 25yrs.
Yamaha had built smaller pumps before the superjet was introduced, and improved with their experience.

 

[bored&stroked]

The FX1 is supposed to be the 550ish style hull from yamaha. It had a tiny little pump in it.

 

[kevbo]

I remember when Superjets couldn't beat a decent 550 anywhere.

 

[snowxr]

I remember when Superjets couldn't beat a decent 550 anywhere.

Yes. That was 1985, and the superjet hadn't been built yet.

 

[kevbo]

Yes. That was 1985, and the superjet hadn't been built yet.

Superjets didn't catch on and do well in racing until 1994 when slalom was removed. At the time we were most interested in going fast and jumping wakes. We thought the 750 s were better at the time. I eventually got the power out of the Yamaha and never looked back.

 

[700Pirate]

When i was 11 this was the shonet .

 

[mthomps]

You're seriously off base with your statements. Kawi has had 4 pump designs for stand ups over the past 42yrs. The sxr pump is based on the 1992 pump, which is derived from the 1986 650 pump.
Yamaha has 2 main. pump designs for stand ups over the last 25yrs.
Yamaha had built smaller pumps before the superjet was introduced, and improved with their experience.

The models that circulate the used market tell me I am on to something. If I buy a Yamaha standup 90% of it fits what you have/had/want to do. Kawi had a lot of platforms. I own a kawi manual for my 300sx that also has like 3 or 4 other skis included making it a 600 page manual. Parts for anything but a 550 are expensive and the reason is the 550 parts and all the others are different.

With my Yamaha superjet every bolt lines up and the separation between older and new models is power they discovered through further engineering their concept. The physics of the engines improved while the bolt patterns stayed the same and the only time you need to deal with adapting those bolt patterns is when you try to put a t top end to an x manifold or vise versa. (same thing with the cases) And the only reason that problem exists is because so many people will buy a Yamaha couch for the motor to put it in to a stand up. That said the popularity is the modularity of Yami's model. Also BRAP factor.