Factory pipe head pipe differences

[durhamgoat]

I have looked all over and at one time I found a picture of the difference between a factory head pipe for sxr and a factory B pipe. There is some difference at the mounting flange but there is also a rotational difference around the mounting to the manifold which makes a difference with my expansion chamber rubbing the hull.

I am thinking with one head pipe instead of the other I can get the rubbing to stop, anyone know where I can find this?

 

[Factory928]

Nice avatar, I see you customized my picture =)

 

[durhamgoat]

LOL Someone customized it and posted it in the freestylefest thread and I grabbed it.

 

[Big Kahuna]

The Offset for a Kawi is greater than the Yamaha...........

 

[durhamgoat]

I'm running a Kawi in a wdk hull ant the pipes do not align so I was hoping changing to a different pipe might fix the misalignment.

 

[stagesrt4]

only difference that I know of this that the base where the head pipe bolts to the manifold is roughly an inch thicker then the yamaha

so if your having pipe clearance on exhaust manifold when running kawi head pipe... then switching to a yamaha might fix that...(yamaha guys cant run kawi tho)

 

[durhamgoat]

One picture I saw showed a top view and I seem to recall that the head pipe was a little more rotated. It could be that the bolts were just drilled different in the flange though. Thought I would ask around before milling my head pipe to allow the rotation I need.
You can see in the pic they don't quite come together and this is after some slotting on head pipe and denting of expansion chamber.

 

[stagesrt4]

I buy yamaha head pipes for all my skis whether its a kawasaki or yamaha.... that way I have more possible buyers when i decide to sell

 

[N3vrSat1sfied]

One picture I saw showed a top view and I seem to recall that the head pipe was a little more rotated. It could be that the bolts were just drilled different in the flange though. Thought I would ask around before milling my head pipe to allow the rotation I need.
You can see in the pic they don't quite come together and this is after some slotting on head pipe and denting of expansion chamber.

its the manifold that rotates the head pipe.

 

[durhamgoat]

Thanks n3vr this is a top view of my mount. Sure looks like a Yami but the FP people insist the manifold is a Kawi.

 

[Big Kahuna]

Kawasaki's Headpipe is called an "A" Type. Yamaha is the "B" Type. The head pipes are different. In some applications they can be used in same hull.

 

[TheBuzzard]

i use kawi head pipes on superjet and they are exactly the same except for the mounting flange thickness. the kawi pipe is 1/2" thicker than the b pipe. i like the thicker kawi ones cause i've seen the yami ones crack. the thicker head pipes raise the whole thing up, so there is a slight clearance issue where the yami factory pipe manifold has an indentation where the head pipe barely clears. the kawi 750 limited pipe uses that cockeyed manifold that rotates the headpipe. all other manifolds line up the same. the old kawi A pipe only has 2 screws and those head pipes were used on the kawi 650 SX x2 annd the yami 650 superjet factory pipes.

 

[Ducky]

the kawi 750 limited pipe uses that cockeyed manifold that rotates the headpipe. all other manifolds line up the same.

Yep, that is why it looks more rotated.

 

[durhamgoat]

what sucks is i bought a new sxr manifold, headpipe, and chamber kit from factory pipe this spring and it is the 800 manifold but for whatever reason I need it to rotate more like the 750 limited. I even called them and they had no idea and told me I was wrong, really frustrating. I have had bad luck with 650 diverter manifolds leaking water at the gasket mating surfaces so I weld them up, guess I will have to do another one now. Pictured is the one they sent me, after welding and before I finished match porting it to my cylinders.
The more I look at this picture it looks like they bored it wrong. if the holes were rotated a couple of degrees clockwise I would be fine.

 

[TheBuzzard]

wdk hull

this is your problem

 

[durhamgoat]

LOL not.

 

[durhamgoat]

The more I look at that picture the more it looks like it was just not drilled and tapped in the right location.

I've got an 865 and it seems like pushing that exhaust through what is essentially a glorified 650 diverter manifold seems like a huge restriction. Has anyone ever used a 4 bolt 750 manifold with the significantly larger port than the 650 and just adapted the 3 bolt headpipe to it? I can weld up the 4 holes and then retap for 3 holes in whatever rotation I prefer for the expansion chamber to fit the best in my hull and then match port the manifold to the headpipe. Should make a big decrease in restriction.
Thoughts?

 

[j0hnny]

i haven't heard of that. i ha heard of boring out the exhaust manifold to 53mm i think it was??? essentially 5mm over

 

[durhamgoat]

I'll have to measure the diameters and post

 

[King of Hack]

Like everyone is saying the flange is thicker on the kawi. The head pipes also have a 3° difference in bolt pattern. Also noticed the kawi head pipe is stamped factory pipe and the yami says factory b pipe.