Identifying Big Small Pin Kawasaki 750 Cylinders

[michaelart]

I am attempting to identify some Kawi 750 cylinders Big Pin vs. Small Pin. Feel free to chime in any time. Struggling to identify the difference between big and small.... I know I have one big and what looks like many small. Look at the pictures posted and tell me what you know. From what I can tell from what I have, the big cylinder has a big nipple on the base/intake/coupler side and the small has a big nipple in the base/intake/center side. Also the Big pin has a bunch of raised lines beginning at the base/intake side. Look at the pictures included and compare to what you have and contribute to this thread.

 

[michaelart]

Pictures with nipples circled......LOL

These 2 pictures have the nipples circled (a piss poor attempt at that, but I tried).......you will need to blow it up to see the piss poor circling......

 

[michaelart]

BTW..... I know color should be a dead give away but what if it has been bead blasted, etc.....know what I mean?

 

[BlueBreadTruck]

werent all big pins green?

 

[shawn_NJ]

I think 95 big pins were silver and green there after but not 100% sure.

 

[Crab]

Small pins had 10 intake bolts, big pins had 12.:beerchug:

 

[sflsurfrider]

intake bolts? on the cylinders?

 

[Crab]

intake bolts? on the cylinders?

Errr, I was thinking engine.:shrug: Sometimes I am typing faster than my brain can think.

 

[michaelart]

Was going to post this in the tech forum but I am not allowed.

 

[joshuaeric]

I could be mistaken on this but:

I have always read that the difference is with the pistons/rods.

The big pin and small pin refers to the pin that connects the piston to the rod.

So I would think the cylinders would be identical.

But I have read that the porting may be different as well, and I would assume a wider port may indicate the big pin motor.

 

[tor*p*do]

small pin cylinders (early 750sx models) are supposed to have better port timing for bottom end and freestyle
big pins more for speed.
i will go check my 92 750sx original motor and see what I find

 

[tor*p*do]

back from the garage.
gray cylinder, nipple in the middle = small pin cylinder
I would assume the green one is big pin
my 750sx small pin cylinder below

 

[michaelart]

thanks torp....exactly the kind of thing I am looking for. Now if we can get some more people to chime in with their big or small pin cylinders. My hope is that this could be an easy definitive way to identify the difference at a quick glance.

 

[227]

Big pin/small pin refers to the crank and doesn't have anything to do with the clylinder. A "Big pin" crank came in all 750 SXI motors which went into production in 1995. The pre 95 750 SX's all had "small pin" cranks. The difference in the clylinders is the port timing. They are all bolt on interchangable. All the 750's both the sx and the sxi have weak bottom end, although the sx is better than an SXI. The best Kawi build is to get a 2003SXR 800 cylinder and bolt it on your 750 bottom end. (Yes it will bolt directly to your 750 bottom end with no machining necesary) The SXR 800 cylinder has a much better port timing set up for bottom end.

 

[michaelart]

227 thanks for that info. I am aware of wrist pin diameters and such, but what I am trying to find is a surefire very easy way to spot the difference between small and big pin cylinders (aside from the color).

 

[DangerBoy]

You would be better off measuring the Exhaust port height.
43mm 41mm 40 mm. ( on an unaltered cylinder) there were different cylinders on the same years skis that had different models ie 750 xir, ss, sx as far as I know that is the only definitive way,

Generalization , the higher the exhaust port = less bottom end more top (at higher rpms

 

[dbrutherford]

You would be better off measuring the Exhaust port height.
43mm 41mm 40 mm. ( on an unaltered cylinder) there were different cylinders on the same years skis that had different models ie 750 xir, ss, sx as far as I know that is the only definitive way,

Generalization , the higher the exhaust port = less bottom end more top (at higher rpms

The winner! When looking at cylinders, measure the exhaust port height.

Crab was right about cases, count the intake bolts.

95 ZXi was silver, the rest of the big pins were green as far as I know.

If you need any more info read up here on the differences, Harry really goes into differences:

http://www.groupk.com/k750.htm

 

[Crab]

Its my understanding the SXR has bigger bore than the SX, but the porting for low end is better on the small pin SX cylinder, exhaust ports are lower.

 

[michaelart]

Thanks for the info guys. Although most info provided I was already aware of, I did learn a few things. Bottom line for asking is I have several Kawi 750 cylinders and I am going to be selling some of them with fresh bores/hones and new pistons. So I want to be sure I represent them correctly.

 

[XFT LOU]

Are all the kaw 750 small large and 800 take the same base gasget