Thread: Rotary valve change/mod
06-16-2009, 11:17 AM #1
Rotary valve change/mod
Does anyone have experiance with changing size on rotary valves? The 657 I have is a 159' stock, but Im wondering how much of a change going to a 147' will have on the low end, and how much it will take away from the top end. Any ideas?
06-18-2009, 10:40 AM #2
So no one has ever ran anything but a stock rotary valve??
06-18-2009, 06:54 PM #3
- Join Date
- Feb 2006
- Warner Robins, GA Home of the 2007 All-Star Little League World Champions!
It's not worth it. You give up max rpms for a better holeshot, and vice/versa. The stock one is best.
06-19-2009, 10:14 AM #4
I already have a new ss 147' lying around, and I may throw it in just for fun and see how it is. However, Ive decided to pick up a carbon fiber 159' to use normally.
06-19-2009, 02:34 PM #5
I read in another post that the CF valve isn't advisable due to eating up the cases... I'm sure someone will chime in and let you know.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By 1fastxpp in forum 2-Stroke PerformanceReplies: 3Last Post: 08-17-2010, 09:53 AM
By DKFox in forum 2-Stroke PerformanceReplies: 3Last Post: 03-16-2009, 09:52 PM
By RX951 in forum Yamaha Open DiscussionReplies: 7Last Post: 11-21-2008, 04:40 PM
By DarthAWM in forum 2-Stroke PerformanceReplies: 4Last Post: 05-04-2008, 08:30 PM
By hotrod_sxty8 in forum 2-Stroke PerformanceReplies: 4Last Post: 09-02-2007, 10:17 AM