Hi Guys
Please help me

I want to mount a TK +1,6 Cranksaft In one RCMK RZ 254 .
What changes should I do for it. It is enough to mount one new base gasket and and how thick?
Thanks

If your RZ 254 has 4 brgs., you have to get a non reduced diameter ( straight ) TK 29.6 mm. stroke crank. TK cranks come straight and reduced. The reduced ( mostly called "tapered"- there is no taper ) crank will only seal on 2 brgs. and 2 rubber seals.

The 29.6 mm. stroke will send the piston higher by .0315", and lower by the same amount. The only accurate way to know how much piston to head clearance you will have, is to measure it with a dial indicator, mounted in the spark plug hole. If you simply add .030" MORE gasket height, you will have a "soft" stack of gaskets, and your exh. and transfer timing will be raised 6 to 7 degrees, and your int. timing will be decreased by 6 to 7 degrees. You are re-engineering the whole motor. If you did stack gaskets, you would be far better to use rigid gaskets like the copper ones. NOT the Zen copper gaskets, they will restrict flow on an RCMK.

The proper way to do this, is to machine the squish band of the combustion chamber the necessary amount, and measure the clearances with a dial indicator. This leaves your port timings almost the same as they are now, and it substantially increases the compression and ratio.

This is not a simple bolt-on.

Can someone list the part numbers for the straight and tapered T K cranks. Thank you in advance. Don