new piston

[Madhead]

Hi guys,

I decided to change the piston of my '09 EC 300.
It's got 150 hours on it.
I have an A size cylinder and had it measured with 72,00mm by a machine shop.
Standard is 71,99mm according to workshop manual. That means I can go to a B size piston right?

[v-tec]

Originally Posted by Madhead

Hi guys,

I decided to change the piston of my '09 EC 300.
It's got 150 hours on it.
I have an A size cylinder and had it measured with 72,00mm by a machine shop.
Standard is 71,99mm according to workshop manual. That means I can go to a B size piston right?

What size was your original piston,if the bore is ok and you are not honeing it, i would the same size piston,

V-tec

[Madhead]

the original piston is 71,93. It's a size A piston

[v-tec]

Originally Posted by Madhead

the original piston is 71,93. It's a size A piston

Hi Madhead,
Without having the cylinder in front of me to measure, it is very hard to pass good advise, but if your original bore has been measured up and in good shape i would replace the piston size like for like, Thats just my own opinion,
I have never had a problem, Hope this helps you.

V-tec

[Madhead]

well I had the cylinder measured up and the measurement was 72,00mm.

[v-tec]

Originally Posted by Madhead

well I had the cylinder measured up and the measurement was 72,00mm.

I think you will be fine with a new piston of the same size, is there much wear on the piston,

V-tec

[Elvis74]

the gap between the piston and the cylinder should be 0,05 to 0,06mm

cylinder 72,00 => piston 71,94 - 71,95mm

[Madhead]

so I made the right choice and am even on the safe side.
Many thanks

[GMP]

The difference is so small that it will not be a problem. Also, you have to have a VERY good properly calibrated bore mic to accurately measure the cylinder. I have one at work and used to do this, now I just go up a size or two from stock, depending on what is available, and have had excellent results.