piston size

[blastblast]

Hi new here and have a question.I need a new piston and I'm going to go big like. 080 over or 68mm whichever way u want to say it.this is my first 2stroke and I need to know if there is anything else I need to support a. 080 over piston.as of now it is all stock except for an fmf slip on muffler.thinks in advance for the help.

I know this will come up....the reason I want to go so big is the cylinder wall a has a good notch right above the exhaust port and Im sure I'm going to go about that big to clean it up.

 

[scotj77]

you shouldn't need to change anything. really nothing changing.

 

[blasterdemon7]

DO NOT bore it any larger then what you need. It will not give any real power increase and is a wast of cylinder life.

 

[blastblast]

So I don't need to change jets or anything?I was going to try. 060 but my machinist said .080 was going to be closer.think you for the help

 

[Blaaster]

No need to re jet!

Only let your machinist clean it up enough to remove that notch, no need to waste bores, a mm is not going to increase power.

 

[blastblast]

Do I need to change anything if I do some port and polishing wile I have it apart?

 

[Blaaster]

If you port and polish you may need to up the main jet, depending how much you take out.

 

[blastblast]

WellI'm not going to really port it just polish up the intake and exhaust just for better flow.

 

[Blaaster]

WellI'm not going to really port it just polish up the intake and exhaust just for better flow.

Do not polish up the intake toooo shiny, rumors have it that it can upset atomisation,.

But remove all casting marks and imperfections on the intake and polish the exhaust port like a mirror.

It should breathe a little better, but you will need to plug chop to see wether a jet change is required.

 

[blastblast]

Plug chop? Talking about reading the plug?

 

[blasterdemon7]

Don't know if you seen it yet but these are some Awsome vids.
http://www.blasterforum.com/engine-13/cylinder-porting-diy-25773/