[arsenic]

no, read my post dude, the 1990 is the long stroke with screw type valves. It's NOT a mismatch, that's how it's supposed to be.

[loudnlow7484]

749's are all long-stroke, 748's are short stroke. In theory you could use the long stroke top end on a short stroke.....

You would have to bush the rods to accept the smaller wrist pins
Machine the block for the shorter stroke
Use the original kat cam sprockets on the gsxr cams
Might need to do something with the oil return lines, since they are designed for a set height
Possibly use shorter studs, or maybe just spacers on top of the head

And then you would end up with a 690cc engine....

I think it would be more productive and less expensive to just get yourself another kat 750 head.

[ohio750kat]

So there are long stroke motors with both shim and screw type adjusters? If so that is what has me tripped up because that is what I have.

[arsenic]

sure are. The 98+ 750 is a long stroke, it has screw adjusters, the 600 tuna also

[ohio750kat]

Sorry, should have specified early gsxr not kat

[arsenic]

you did, I just used the tuna as an example. YES, THE 1990 GSXR 750 IS A LONG STROKE ENGINE

[ohio750kat]

no, read my post dude, the 1990 is the long stroke with screw type valves. It's NOT a mismatch, that's how it's supposed to be.

Ok, got that. What year is a long stroke gsxr w/shim type head?

Also, the serial number prefix on all early gsxr's is "R716"?

[arsenic]

91-92

[ohio750kat]

thanks for the info.....

One more question....since the 90 and 91/92 grxr motors are both long stroke, can I use the 90 cylinders/pistons on the 91/92?

[arsenic]

yes

[ohio750kat]

Thanks again for your help.I don't know why it took me so long to figure out what you were saying.A lot of people would have given up. Thanks again

[arsenic]

glad I could help