JE Piston 13.5 to one in 450f


58 replies to this topic
  • gtxkid

Posted May 24, 2007 - 06:34 PM

#1

What do you guys think of this.:bonk:
I know it cuts in half the time a piston need to be changed.:D
I am here in Colorado and would like to make race fuel work.
What kind of power increase will i see.:)
Greg :ride:

  • Jessthro

Posted May 25, 2007 - 04:05 AM

#2

i know its a different bike but i also have the 450 yfz. i did a port polish and threw in a 13:5.1 piston. it gained huge snap off the bottom. it dynos at 57 hp (with exhaust and filter and jetting). which means it has more hp than my yz 450 and tons more bark on the bottom. i run c12 from vp and its great. u4 does give a hp extra but its so expensive but if thats no problem then its the way to go. i would think the gains would be similiar in the bike, i know high comp. pistons tend to bump the bottom end considerably.

  • 642MX

Posted May 25, 2007 - 03:40 PM

#3

The higher compression pistons last just as long as the stockers. They increase the bottom end and mid-range power. I'm happy with mine. I'm a bigger guy and I like the extra boost!

  • gtxkid

Posted May 25, 2007 - 09:25 PM

#4

Looks like 13.5 to one it is then.
Thanks

  • 642MX

Posted May 28, 2007 - 03:42 PM

#5

^^^^ Most will run fine on premium pump fuel. Kawasaki's come from the factory with a 13.5:1 piston and they only require 91 octane.

  • grayracer513

Posted May 28, 2007 - 05:14 PM

#6

Italy may be selling fuel rated by the Research method. Even so, only about 96-98 (RON) is really needed in most modern MX 4-strokes, even with that much compression.

  • gtxkid

Posted April 12, 2008 - 06:36 AM

#7

Well i will find out tomarow at the race what i think.
It also had four valves that needed adjustment.
$709.29 Included some other work also, change tire's, regrease steering head.

  • kawboy388

Posted April 12, 2008 - 11:28 AM

#8

^^^^ Most will run fine on premium pump fuel. Kawasaki's come from the factory with a 13.5:1 piston and they only require 91 octane.


Who told you this ? Kx450f's come with 12.1:1 comp pistons.

  • 642MX

Posted April 12, 2008 - 12:29 PM

#9

Who told you this ? Kx450f's come with 12.1:1 comp pistons.


The KX250F has 13.5:1 and the 450 actually has 12.0:1 compression.

  • gtxkid

Posted April 14, 2008 - 03:55 PM

#10

Well it worked out great.
It did what i wanted it to do.
Came to 671.00 with a few other things i had done.
I like it.
I will bet it will work even better when i get a new pipe.
I realy do not want a pipe to go after gobs of power because i am 48 years old, i want controlable power.
Just want to increase the bottom end and mid range.

looks like the compression ratio stock was 12:3:1.
Greg

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  • gtxkid

Posted April 14, 2008 - 04:02 PM

#11

Well it worked out great.:thumbsup:
It did what i wanted it to do.
Came to 671.00 with a few other things i had done.:thumbsup:
I like it.:confused:
I will bet it will work even better when i get a new pipe.
I realy do not want a pipe to go after gobs of power because i am 48 years old, i want controlable power.
Just want to increase the bottom end and mid range.

looks like the compression ratio stock was 12:3:1. :ride:
Greg

  • gtxkid

Posted April 14, 2008 - 04:16 PM

#12

Ended up going with the newer CP Piston 13:75:1
Greg

  • gtxkid

Posted November 30, 2008 - 02:54 PM

#13

UPDATE on CP piston

Well since 4-14-2008 The piston has worked realy well.:bonk:

  • 642MX

Posted November 30, 2008 - 04:22 PM

#14

UPDATE on CP piston

Well since 4-14-2008 The piston has worked realy well.:bonk:


How many hours have you put on it?

  • gtxkid

Posted December 28, 2008 - 06:43 PM

#15

i have 77 plus hours on it now.
I put it in a little over 20 hours i think.
Hope it will get me threw some of 2009.

  • erickdj

Posted December 29, 2008 - 04:39 PM

#16

i have 77 plus hours on it now.
I put it in a little over 20 hours i think.
Hope it will get me threw some of 2009.


are you able to run it on 91 pump gas?

  • pbviking

Posted December 29, 2008 - 05:02 PM

#17

Can you put the 13.5.1 piston in a YZ 426?

If so where can I find one? The TT store for OEM parts is going through some remodeling

  • grayracer513

Posted December 29, 2008 - 07:31 PM

#18

You can't get a 13.5:1 piston from OEM parts, anyway. Call the TT Store.

  • pbviking

Posted December 29, 2008 - 08:09 PM

#19

You can't get a 13.5:1 piston from OEM parts, anyway. Call the TT Store.


thank you

What else would I need besides the piston, rings and ????

What brands would you recommend?

  • grayracer513

Posted December 29, 2008 - 11:28 PM

#20

Head and base gaskets, wrist pin, new clips from the piston manufacturer (don't mix OEM clips with aftermarket pistons using a different type of clip). Get a tensioner gasket, too.

For brands, CP, then JE.





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