Riding withYamaha GYT quiet insert.
Posted April 07, 2003 - 06:43 AM
Well yhat insert really made my ride quiet but it lost at least 25% of its power. Turned it into a real pile.
Any similar stories out there? I figure I can rejet leaner but doubt if I'll see acceptable results.
Posted April 07, 2003 - 06:52 AM
Posted April 07, 2003 - 07:46 AM
Posted April 07, 2003 - 07:52 AM
The power loss from just off idle though the midrange was the most notable and disturbing for me. I realize some rejetting may help, but don't know if I can stand all the weakness.
Has anyone with both the GYT-R and the Pro Moto Billet ridden both and compared?
I'm considering either modifying the GYT-R or building my own insert. What do you all think would result from drilling some holes in the tubes on the GRT-R? I'm thinking maybe a series of 1/4 or 3/8" holes on the tubes. Would that improve flow or interfere with the existing flow?
What jetting changes has everyone been making when they go from uncorked to the insert?
Posted April 07, 2003 - 08:24 AM
Posted April 07, 2003 - 08:29 AM
I run a Baja Vortip in my WR426. I think the GYT insert will perform the same. I run stock jets with the needle on clip 5 and the bike rips. Open pipes like E taper needles, baffled pipes may not. I would try the stock D taper and raise the needle one clip. I did the James Now mod. and went in approx. 1/2 turn on the fuel screw from stock. Starts great, hot or cold and from the bottom to WOT it jumps.
Posted April 07, 2003 - 12:28 PM
Posted April 07, 2003 - 03:45 PM
And yes, my YZ250f almost felt as powerful overall as the stock 02 WR426 pipe with stock vortip.
Posted April 07, 2003 - 04:34 PM
Stock jetting was 42pj, 4th position needle and 150m.
Uncorked: 48pj, 5th position needle and 158 main.
PMB/GYT-R: 45pj, 4th position needle and 158 main.
I'm at 2700ft. elevation. I'm currently at two turns out (on the pas) and I think the bike runs very well considering. It's warming up more and more so this will need to be tweaked a bit...but overall I'm satisfied with it.
Posted April 08, 2003 - 04:17 AM
The WR450 service manual lists the stock US pilot jet as a 45 but you listed your stock pilot as a 42. Did you pull out a 42 when you started your jetting adventure?
FYI – your feedback reads well and sounds creditable. That is something I find refreshing. Thanks
I am still waiting for mine…..
Posted April 08, 2003 - 04:30 AM
I can also ride it in my subdivision without the neighbors hearing it from a mile away.
Posted April 08, 2003 - 05:38 AM
Are you running stock needle? I've got a YZ needle I'm about to install. Just added the Baja baffle and having a bit of low-end stalling right now. Riding about the same elevation as you but probably a little warmer (N. Ga). My plan is to richen up fuel mixture screw, 155 main, stock pilot, YZ needle on 4th click.
Posted April 08, 2003 - 05:54 AM
Posted April 08, 2003 - 06:03 AM
Its possible to get good throttle response with the insert, just keep tuning till you get it.
Posted April 08, 2003 - 06:09 AM
What up with you !!!! All the trouble of getting my GYT-R insert and now you are saying the PMB is better? That sucks! I think I am gonna save some ka-ching for a new pipe.
Posted April 08, 2003 - 06:32 AM
Posted April 08, 2003 - 06:55 AM
BTW, I'm having way too much fun with these new graemlins!
Posted April 08, 2003 - 07:51 AM
We will have to get together here in the next 2 - 3 weeks.