R&D dominator setup

[norcal ex]

I have an R&D domminator setup. something that has been bothering me is the fact that its decked about1/4" or less overall . it is made for flattop pistons, but would this be for dominator flat tops or kawi flat tops?

 

[waxhead]

kawai flatops are 4mm higher in the wrist pin
so this is why you see that machined part
the piston sits lower due to the higher wrist pin

 

[norcal ex]

so are you saying that my cylinder is for kawi flattops?

 

[SUPERTUNE]

Dominator pistons and Kaw big bore pistons are close to the same, they do have the same deck height, but the Dominator pistons have the skirts cut to fit the yamaha cylinder, the ring pins are moved in closer to fit the wider transfer ports on the dominator sleeve, and have thinner rings and are a lighter overall piston assembly weight. Kaw pistons work, but require piston skirt maching to fit in the yamaha cylinder. Your best set-up would to use the R&D pistons so you don't have any chance of the rings snagging in the dominator's wider tranfer ports.

 

[norcal ex]

I WANT the R&D pistons, I just didnt know why the cylinder was decked so much. So its normal than? Ill get a measuremnet after school.

 

[norcal ex]

The best i can tell is the difference is 4mm. a stock cylinder i had came in at 120mm while the R&D came in at 116 or so. Is this right for the R&D pistons?

 

[norcal ex]

And Supertune, how do i contact you about carb work prices?

 

[SUPERTUNE]

PM sent...

 

[norcal ex]

I threw in some stock domed pistons today to see how much they stick up. Overall the deck is 4mm when i compared it to a stock cylinder.When i measure the piston in the attached pictures (the Very lowest part of the domes) to the top of the cylinder it is 4mm. I just want to make sure this is correct? I dont know why i am so nervous about it, bret said it is suppose to be for R&Ds not kawis

 

[duckman1]

They have different shaped domes also, if you use an R&D piston in a head with domes designed for Kawi pistons, you'll have an inverted squish...runs okay, but not the best idea.