Friday, March 28, 2014

The Care and Feeding of a Yamaha TZ250 Grand Prix Machine

“Tribal Knowledge” is an unfinished work based on what I learned about tuning a TZ250 by racing a few of them in Hawaii and North America. It was my idea but I needed a writer. Jim Hubert wrote it based on a few long phone conversations. Michael Gougis helped with the editing. The knowledge herein is not mine, it is the shared knowledge of a community of racers and it is yours to use. By using this knowledge you are obligated to pay it forward.
Ed Sorbo 3/26/14

Please go to Ed's website to read the entire informative article.

Tribal Knowledge
(The Care and Feeding of a TZ250)
Copyright 2004, Jim Hubert

This article is the culmination of a series of conversations with
former 250cc GP front-runner, Ed Sorbo. For those of you who don’t
know Ed…
Best race of all time: Brainerd in ’99 Finished 6th. Started
from last on grid. 15 MPH slower than the guys racing with.
Announcer said he moved from paradise to live in a motorhome. That
From the outset, Ed wanted it clear that although he might be the
one willing to sit still long enough for me to write it all down,
the information contained herein is not all his own discovery. Ed
feels indebted to a number of racers and tuners, especially his
racing partner — Bruce Lind. In fact, it was Bruce who coined the
phrase “tribal knowledge pool” when referring to the body of
information amassed by TZ racers. This article is a start at
disseminating that knowledge. Most of the information is hands-on
nutsy-boltsy stuff but there is a fair mix of theory for those of
you who want to know “why” instead of just “what.” Don’t be scared
off by this because, as Ed is fond of pointing out, “If you’re
smart enough to ride the motorcycle, you’re smart enough to work on
This article discusses the 50.7mm-stroke vees from model years 1991
to 1999. Those model years comprise the bulk of the machines
inexpensively available. If fact, Ed estimates there are probably
1000 such machines in the US today. The AMA’s opinion
notwithstanding, 250cc 2-strokes are not going away overnight.
Considering that most parts for the ’99 model are backward
compatible to the ’91 machine, and that Yamaha is obligated to
provide parts for 10 years for a given model year, racers should
have ready parts availability until at least 2009. Additionally,
Ed believes that if there is sufficient demand, aftermarket
suppliers could step in to fill the void.
In many ways, the short-stroke vee engine represents a good
compromise for the racer on a tight budget. For one thing, the
engine cases — which are based on the TZR250 street bike — are
pressure cast. This equates to a longer life span than the sand-
cast cases used on 2000+ models. Similarly, the short-stroke
engine should have a longer service life than the “square” motors
which are more heavily stressed.
Ease of Maintenance:
Ed says many racers get the wrong impression of how much effort is
required to keep a TZ in top condition. “They see us working on
our bikes all the time and figure it’s a bitch to keep them running
right.” Quite the opposite is true, “We work on the bikes because
it is so inviting. Ease of maintenance was high on the list of
priorities when the TZ was designed.” For example, an experienced
mechanic can remove and replace a TZ crank in an TWO HOURS, BRUCE AND I DID IN 1.5 ONCE hour at the
racetrack. The crankcases split vertically, so that the bulk of
the engine can remain in the frame for the procedure. If you
destroy the crankshaft in a 4-stroke, your weekend is over.
Full Disclosure:
Racers endorse products and services for a variety of reasons –
sponsorship, contingency money, perceived value, future
consideration, and friendship immediately come to mind. When we
mention a product or service by name, it is entirely possible that
an alternative, competing one, will work just as well, perhaps
better, for you. We have endeavored to be as objective as
possible. In some cases (Rino fender, for example), there is no
competing product. In others cases (Kawasaki wrist-pin trick), we
hope it is apparent that we don’t have an agenda to forward.
However, in the interest of full disclosure, we want you to know
that Ed was WAS AT DIFFERENT TIMES (IS?) sponsored by Silkolene, and received contingency

Please go to Ed's website to read the entire informative article.

Brought to you by:

 Steven Aspland

Wednesday, March 26, 2014

Start Sharing Your Gauges Today - Dashware

An excellent complement to our
Qstarz GPS Data Logger
and Lap Timer product line 

Start Sharing Your Gauges Today
e are happy to announce the release of DashWare version 1.5
with guage importing and exporting built in.  Now, you can
easily share your custom gauges with your friends and colleagues.

To see it in action, view the video tutorial on our website.

Customers can get version 1.5 for free at the
Download DashWare page on our site.

Also, we are adding a gauge sharing section to our website
in April.  You will receive another email when it is ready.

Have fun,
The DashWare Developers

Yamaha TZ250 GP race bike for sale and other Product news as well as listings on eBay

Product Updates
SBS road racing pads available from Rising Sun - Looking for track side dealers

New Products
RS Taichi Glovesunder race suit garments and armor

Products being added to our Catalog
brake line kits
Cafe Racer Items
Parts and Accessories on eBay for Specific Bikes
Honda RS125                   CBR600RR/F4I
Honda RS250                   VTR1000 CBR1000RR
Yamaha TZ125                  Moriwaki  MD250H
Yamaha TZ250                  Yamaha YZF R-6

More listings on our site and eBay CLICK HERE
2003 specification 2007 build Yamaha TZ250
Rising Sun Cycles is selling our
2003 specification 2007 build Yamaha TZ250
Frame # CG15C-000141

Yamaha TZ250
Minimal usage since last total rebuild. Will be dressed up in all white new bodywork.

Save Cash on your Energy Bill
Recently I was introduced to a company which supports the production of Green Power here in the USA. Their sales format allows you to reduce energy costs in the home or business for you and your family and the opportunity to create a lucrative part time business for yourself if interested. The company is expanding across the country as these services are deregulated and at this time they are very active in the North East but offer and means for everyone in the US to contribute to the production of Wind Power.
Click on images for more information

Just like back in the day when the telephone business was deregulated and broken up which allowed many companies to jump in and created competition, the same is happening in the energy business.
WHY WE RIDE and Moto 5 Videos
WHY WE RIDE - a documentary film that shares  
the passion of motorcycle riding


From the creators of the epic film series "MOTO The Movie", The Assignment Inc. is proud to present their latest and most anticipated installment to the film franchise, "MOTO 5". Without reservation this is by far the biggest and baddest of the "MOTO The Movie" films.

Guide to Guitar Patterns

Helping a friend and fellow racer to market his very well thought out guitar lesson series. Check out the sales page if you plan to learn or already think you understand the instrument. CLICK HERE

Learning Guitar from a different perspective - When you see the simplified presentation of fret patterns you will be amazed at how easy this will make getting by the initial steps of understanding the mechanics of guitar playing.