tz250, tzr250, yamaha, shift kit, detent arm, tuning test data, factory, pro, eddy current dynamometer, ec997

FP Microbearing Detent Arm SHFT-PRO-YAM-25 (fits 92 and up) $89.95 1. Choose your shipping method 2.	Factory Pro TZ250 Transmission Detent Arm Decreases shift duration 5 to 10 ms. Dramatically improves downshifting. Virtually eliminates missed shifts. Lessens foot pressure required to up and down shift. ............................................... So, there you are. - with your real racebike and all......... How could a company like Factory Pro could POSSIBLY ever improve on a genuine Yamaha RACE part! Heck! Factory Pro is in northern California - NOT even in Japan! How could Factory Pro even think that they could make a better part than the other "factory" guys???? Actually......... The goal was to make the TZ/TZR shift as well as an RS 250 Honda. Yeah - now it's better than the RS. Compared to the sketchy stock Yamaha shift action, there is no comparison. The Yamaha shifting is pretty notchy when shifting even Rich Oliver's TZ250 on the EC997 dyno. Hmm. A couple of questions to a few well known Yamaha tz mechanic type guys. "Yep. The Yamaha's shift action is notchy. Yep. Sure is. Yep. Always been like that. Rider complains a lot on some tracks. Yep. We don't know how to make it much better." With the Factory Pro MicroBearing detent arm, instead of dreading quick downshifts into low speed corners, you can downshift easily, without additional thought being directed to shifting, leaving more mental energy to devote to race strategy. MUCH easier and quicker downshifting and improved upshifts. The Factory Pro Microbearing Detent Arm reduces the rotational friction so that the shift drum rotates quicker - the gears engage more reliably under super quick downshift conditions. By decreasing the number of missed shifts, shift forks and engagement dogs last longer. Same feature as our exclusive "streetbike" kits. The Factory Pro Microbearing Detent Arm removes friction for the quickest shifting short of an air shifter. Same feature as our "streetbike" kits. Hmmm... Did I mention that we can even make streetbikes shift with less effort and wickedly quick and virtually eliminate missed shifts?? By the way, this is a limited production part number and includes: Factory Pro Microbearinged Detent Arm, decreasing the effort required to shift and decreasing the number of missed shifts. This kit DOES NOT include cartridge gasket or a stronger detent spring. EVO SHIFT Kits I guess you 250 guys want a box now that will control servo motors and power jets based on engine rpm and throttle position. I'll work on that....... Hmm... I guess you REALLY want 3d mappable ignition timing...... as that's the major limiting factor to power production on the high compression, leaded fuel, USA spec, TZ250's I guess it's a not a secret that we sorted out a whole passel of 250's in the 2002 - 2003 AMA seasons on our High Speed EC997 Low Inertia Dynamometer at tracks all across the USA, too. Try to find even consistent USA top 10 2003 250 person who didn't benefit from the EC997 dyno's use. There IS ONE guy, but, you'll have to find him. First one to find him gets a 50% Detent Arm discount! (Dec 2010 - nobody has found him, yet) If you are doing any 250 dyno tuning at all and were considering using a "dealership level" dyno - it's pretty misleading - as final settings best dyno power settings in a Sweep Test inertia dyno (i.e. dj dynos) are 10% to 20% off of the correct settings as per the real world results and a High Speed EC997 dyno optimal settings - Marc BTW: EC997 Dyno was used and tested on by AMA / Stargel Racing's Chuck Sorrensen, Rich Oliver, Jason DiSalvo, PM's Roland Sands, Bruce Lind, Jeff Malone, Ed Sorbo, Simon Turner, Greg Esser, Corey West, Sandy Noce, Sean Wray, Kent Gormat, Glenn Christianson and many more....

Detent STAR pics below are for reference only.
Information only Detent "star" profile "3XV" TZ250 92(ish) to 2006		hold down bolt: 8.0mmx1.25mm dist across small pawl indents: 32.0mm dist across peaks:41.0mm mount hole (backside) 16.97mm overall height: 21.3mm

	Rich Oliver #1 tz250 EC997 Dyne System tuned	John France rs250 EC997 Dyne System tuned
	Chuck Sorensen #1 Stargel Aprilia EC997 Dyne System tuned	Greg Esser rs250 EC997 Dyne System tuned
	Simon Turner #3 tz250 EC997 Dyne System tuned	Bruce Lind tz250 EC997 Dyne System tuned
no pic	Jason Di Salvo Cruise America rs250 EC997 Dyne System tuned
Factory Pro proved that dynos CAN WORK in tuning these high strung GP machines. The EC997 dyno is the only dyne system that was primarily designed to tune to the "Nth" degree and that's what riders, racers and tuners want. Common "dealership level" dynos just don't do the job. In other words, if we could consistently make all of these top ranked 250 Grand Prix riders happy - the EC997 dyno and it's own integrated Hi Speed 4 gas EGA should be the the Number 1 choice of any aspiring tuner.

Subject: Thanks from Bruce Lind
Date: Wed, 20 Jun 2001 23:55:57 EDT
From: Tzrider2@aol.com
To: Marc@factorypro.com

but I am concerned about the ignition cutting out or misfiring under load.

I make a decision to revise a long standing personal position and run my bike on the Factory dyno. If it does not misfire under that load, then it won't on the track. This will also give me a chance to see what the exhaust gas analyzer shows for the fuel curve with the jetting I have installed and give me a relative indication of horsepower.> >

Off I go.

Marc and Paul are both there. Just finishing up another TZ250.>

I start the engine and roll it up on the dyno. Paul secures the bike and we start the process. He types a bunch of information into the computer. Then we start running the engine at various throttle and rpm settings. When we are all done, the engine has performed
flawlessly. Not only that, the numbers indicate that my set up is very close to optimum. A little fat in the middle and just a smidgen lean on top. One Power jet smaller and and one main jet richer will probably be perfect.

Will I be able to tell the difference in the seat of the pants test? Probably not...

By the way, the (corrected) top number at 12,200 rpm was 75.8 True bhp.

I have been informed that you normally add 15 % to the Factory dyno True HP number to equate to a Dynojet Dyno. So for braggin rights lets say 87 bhp at the rear wheel.

Paul tells me it is the second highest number he has seen on a 250 and very, very close to the highest.> >

Both Marc and Paul have a good laugh when they tell me "Well, it's pretty obvious now why you are not winning races"

I could have told them that. It's not the bike that is holding me back.

Hasn't been for about two decades!>

Bruce Lind

Message: 1
Date: Tue, 19 Jun 2001 19:10:53 -0400
From: "Tony Iannarelli" <tony@samnet.net>
Subject: FACTORY Pro Tuning

I just wanted to publicly thank Paul from FACTORY for all of his input at the recent Loudon National.

I wish I could remember half of the stuff he said about 250 motors!

:-)

Tony Iannarelli
SAMnet Racing
http://www.samnet.net/racingrep
tony@sportriders.com

Links

www.tz250racing.com

www.tz350.net

wikipedia.org/wiki/TZ250