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Got a question about pistons for 300ex
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Posted by: rebelbuggy

Okay I just got home from picking up my piston and top gasket set for my 300ex i got home and looking at the piston I have and the one online and well the one i have doesnt have a flat top, it has like ridges in it and stuff...

I didnt want a high compression piston, but is that what the one I got is? I dont know anything about pistons. My buddy found me one online at http://www.rockymountainatv.com/typ...50&navType=type

and its like $80.00 but this one I got was $118.00 so did I get a better one that I shouldnt have?

it says on the box it is 11:1 CR, is that High comperson or what.

My buddy that knows this stuff isnt home for me to ask and well I was planing on taking it to get it bored tommorrow but dont want to have the dude bore for the wrong piston and have to redo it since I am just about broke as it is...

it is a wisco piston and i told them I wanted it bore 40 over.
Any help would be great.

Thanks

Posted by: Blue250X

That is a higher compression piston than stock, but you can still run premium pump gas with it.

Posted by: rebelbuggy

quote:
Originally posted by Blue250X
That is a higher compression piston than stock, but you can still run premium pump gas with it.

Thats what I was worried about, dang it I knew my buddy should have went with me to order the parts...

What will a high compression do? then stock one

Posted by: Pappy

Please dont take this the wrong way...it is meant to save you some troubles...

If you do not know what piston you have then do not try and install it!

Posted by: Pappy

Sorry, I see now that you added what compression it is!

You should be fine with 11-1, just clay the piston to make sure you have proper valve clearence

Posted by: Xeller8

More than likely you will actually LIKE the higher compression piston....you will probably need to rejet the carb for it too...but hey....better performance is the name of the game!

Posted by: rebelbuggy

quote:
Originally posted by Xeller8
More than likely you will actually LIKE the higher compression piston....you will probably need to rejet the carb for it too...but hey....better performance is the name of the game!

yeah, guess i will call tomorrow or go up there and get them to order me the right one, cause i am just tying to Fix it.. the old piston is all messed up and the cyclinder wall so , thats only reason for this rebuild. i dont care for it to be any faster.

Posted by: Xeller8

"I don't care for it to be any faster"

WOW...thats a new one!.....LOL!

But hey...to each his own...hope you get things straightened out.

Posted by: rebelbuggy

quote:
Originally posted by Xeller8
"I don't care for it to be any faster"

WOW...thats a new one!.....LOL!

But hey...to each his own...hope you get things straightened out.

I hear ya, well my last 300ex was stock and it was plenty fast and I'm boring this one 40 over so its going to be faster already. my friends 400ex scares me I never get out of 3rd in my yard with it.
I just want more metal wraped around me if I am going over like 50 on something like that lol.

I'll keep the speed for my rc trucks.

Posted by: Xeller8

Yeah..well.....I just felt that if you are already in the process of rebuilding it why NOT put the high compression piston in...heck I certainly would!

However...if you are not comfortable with it being quite a bit faster then there is no reason to push it...I guess this all makes sense now.

Posted by: rebelbuggy

quote:
Originally posted by Xeller8
Yeah..well.....I just felt that if you are already in the process of rebuilding it why NOT put the high compression piston in...heck I certainly would!

However...if you are not comfortable with it being quite a bit faster then there is no reason to push it...I guess this all makes sense now.

yeah , I am not into racing just having fun playing in my yard on my small trail in my woods and going riding on trails and all. Im not trying to win any races or anything.

Posted by: bwamos

Honestly.. go with the 11:1.

If you're running stock everywhere else.. you'll just feel more bottom end grunt. The top end will still be to corked up to see much of a difference.

You aren't going to find an aftermarket stock compression piston. I'm not even sure they make one.. lol. I could be wrong, as I've never looked for one.. but I don't remember ever seeing one.

Posted by: rebelbuggy

quote:
Originally posted by bwamos
Honestly.. go with the 11:1.

If you're running stock everywhere else.. you'll just feel more bottom end grunt. The top end will still be to corked up to see much of a difference.

You aren't going to find an aftermarket stock compression piston. I'm not even sure they make one.. lol. I could be wrong, as I've never looked for one.. but I don't remember ever seeing one.

Yeah I went back to the Local 4 wheeler place and they told me that was the lowest compersion that wisco made for the 300ex...

so I have that in it. right now I cant really tell it has any more or less power then my old 4 wheeler but its got huge tires on it (getting smaller ones for it )