Mini ROK Copper gasket

2 Stroke Kart Engine Forums
1

Hi everyone

Just giving my sons mini rok a freshen up and at the stage of re fitting the head. My question is in parts breakdowns I’ve noticed a copper gasket is shown as well as the rubber o ring. Unless I’m going mad I didn’t notice the copper gasket when disassembly. Is this typically used?
Thanks

2

It is there in different sizes to set squish gap.

Measure the gap if you don’t have a copper gasket to ensure correct measurement

You don’t want to tight

It’s ok to run without the copper gasket if squish is good

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3

Thanks very much for the reply Lucas

I measured squish before pulling it apart and it was 0.9. There was some carbon on the piston so potentially it was a little less than that when fresh. So you think I should just re torque the head and check squish again and if I’m in the 0.85 - 0.9 range I just run it again without the copper gasket?

Just for reference I put a 0.4 base gasket as that’s what it had

Thanks

4

Yes that will do it as minimum allowed squish is 0.8mm.

What I use to do with my old engines without copper gasket is to take valve paste. A dab on bot cylinder and head and turn it to make the surface even. Then wipe of all the paste and mount.

But I’m not sure if you are allowed to to any kind of work on mini rok outside of the regulations

5

Great thanks again

I have torqued the head down and get 0.86 squish so I think I’ll call that done. My son is only 6 so not chasing performance just want it fresh so he can continue to do laps and practice.

I’ll fire it up tomorrow and :crossed_fingers:all goes smooth

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6

I am running my vortex rok senior engine with out the copper gasket, at 1mm squish with no problems.

7

Yeah some engines doesn’t need it depending on what base gasket you uses etc😄

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8

So I take it that’s the science, balance between base gasket and copper gasket to achieve the desired squish but why the two options. Why not just adjust it with the copper gasket. Is the basket gasket adjusting intake and exhaust port height or something like that? Sorry if that’s a stupid question just curious about the theory behind it because apart from that and ignition what else could be adjusted to get any performance gains inside of the rules?

9

Not at all a stupid question and yes porting can be adjusted a little (as/if allowed by rules.) with the base gasket.

The ideal situation is that your port timing AND squish clearance are optimal.

10

Gotcha. Thanks very much guys really appreciate the help

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