high comp piston

[6858-400ex]

if i were to put on a high comp piston 0n a 400ex what all do i need to replace becuse of all the xtra stress the only thing i can think of is a crank rod?

[plkmonster2]

If you are doing 11:1 you should be safe up to the 426 on the stock rod. If you want 12:1, I wouldn't do more than a 416 on the stocker. The piston kit usually comes with everything you need.

[400ccBanshee]

Hey stud, high compression pistons are no joke. On a four stroke you have many thing to consider when taking apart and reassembling that motor. Ask yourself......Why do I want a high compression piston? That high compression piston by itself won't do squat. That piston is only one small part to a high performance motor. Things to think about are jetting, fuel, exhaust systems, vavle and cam size. All of these need to be though out before you put a high compression piston in. Otherwise you will be highly disappointed. There is a reason that four stroke engine kits cost $1000 or more. Leave it stock or plan to get out your check book.

[6858-400ex]

is there anything that would have extra stress besisdes the rod

what brand of rod is top of the line

[BLEEDRED]

Hey stud, high compression pistons are no joke. On a four stroke you have many thing to consider when taking apart and reassembling that motor. Ask yourself......Why do I want a high compression piston? That high compression piston by itself won't do squat. That piston is only one small part to a high performance motor. Things to think about are jetting, fuel, exhaust systems, vavle and cam size. All of these need to be though out before you put a high compression piston in. Otherwise you will be highly disappointed. There is a reason that four stroke engine kits cost $1000 or more. Leave it stock or plan to get out your check book.

Although some of this can be true if we all listened to this guy we would be riding utility quads and/or stock sport quads and none of us would be happy. The bottom line is that stock is safe, but it sucks. And yes is does cost a few bucks to build up a decent engine and cutting corners along the way to save money is never a good idea. Do your research before you start your project, the overall end result will make you much more happy.

I would consider replacing the stock rod once you go over 11:1 and you also may want to think about replaceing the head studs with heavy duty studs. Most people will agree that you can run pump gas up to 11:1 but anything over will require race gas or a mix of race and pump for best results.

I'm not sure but I hear good things about the carlido rod, sparks and i'm sure GT Thunder offers nothing but the best. From what I hear Laz is a God and the hook up of all hook ups, just ask Ugly.

[wilkin250r]

The stock Honda rod is pretty dang good.

[BLEEDRED]

The stock Honda rod is pretty dang good.

Until that dude posts the picture of his shatter case. I'm using the stocker with my 11:1 440 with no problems. But when I have it pinned climing a 300' hill of sand I see flashbacks of that picture and cringe.