Yamaha RD250 / 350The R-5, 350, RD 250 and 350 Series were Yamaha's blazing (at the time) street legal, 2 cycle versions of the all conquering TZ250. In fact, a TZ engine will drop right into an RD frame. 
The RD and TZ frames of that vintage, aside from a large weight difference, were pretty similar in geometry, with the TZ frame having a slightly steeper head angle and similar wheelbase. The steeper head angle addresses the relatively slow(?) steering of the RD.
Savvy RD production class racers, back in late 70's and 80's did a few mods, some legal and some "extra legal" mods - including:
TL-float height gauge The only way to accurately measure float heights. Works on nearly every carburetor. recommended
~$49.95 USD


RD Dreams - India

Suggest a link!


True Rear Wheel Horsepower® Factory EC997a® Eddy Current Dynamometer

Tech questionswbn63@comcast.net wrote:
 Hi Mark, I ran across a Factory Pro article (link below) on the Net to increase rebound dampening on the RD400 and I have a question I hope you can answer. There are 4 approximately 1/4-inch diameter holes at the top of the dampening rod. Are all those holes supposed to be plugged up? Do you recommend welding the holes or will another method suffice (i.e., epoxy) ? Thanks for your time Brad Ninnis http://www.factorypro.com/Prod_Pages/prody00.html Not the big holes - those are the compression damping holes -
You can radius those holes to let the oil move a bit easier -
This is real tuning - not just "do this it works everywhere on all tracks for any rider" stuff -
It's pretty "wrong" when stock - though -

The holes that I'm talking about would be maybe 2 of them, small.
Can you take a pic or scan the tube?

The holes can be plugged with braze - no need to weld - Take a welder 5 minutes to do -
Epoxy - I wouldn't - 

Also - there's some shimming of the fork bushing on the inner tube - usually use .0015" feeler gauge stock and you can "dimple the backside of the outer tube bushing to take up some slack.
 The forks should have zero stick, with oil coating and as little "inner/outer tube rock as possible, without the forks binding.

There's also some fork oil additive that I used - It's pretty expensive, but forks work better at small bumps - Def. cut springs  and then make pvc spacers to get good ride height - Oil weight AND!!!! OIL HEIGHT adjustments in 5mm incrememts (not just what they tell you to put in) are IMPORTANT!!!!

Also - sand the inside of the rubber sliders till they just barely contact the inner fork tube for less drag.

Cut a small strip of foam air filter foam and insert it under the rubber slider. Just before you ride it , put a squirt of STP"ish" oil under the boot for tube lubrication





New and improved Teka SFI 2
with new TPS display and "MMT" Memory Module Tuner

Finally - Quick, easy, cost effective Suzuki tuning with no expensive "add-on boxes"
Suzuki cruisers and sportbikes

Please click here for more info

Contact Factory Pro
M-F, 9am - 6pm, Pacific time, -7 or -8 GMT

800 869-0497
 USA and Canada

415 883-5620

fax 415 492-8803

parts information

EC997 dynamometer information

Product Support /Tech SECTION
click here


Mailing / Shipping address:
Factory Pro
179 Paul Drive
San Rafael, CA 94903

And most importantly
Restart back at the HOME page and click on the red box in the top left to find the bike that you want parts for...
restart at HOME page


This Tuning Site has been visited by
www.gigits.com - the oldest counting service on the web





People ask me how I select the below links - as they aren't all mc related.
The below links are people and companies that are consistently impressive with their continual uniqueness and dedication to providing traditionally valued, quality products and services.
EFI and Carb Tuning by Wheelsmith Racing
The Rich Oliver Mystery School will help you discover your hidden inner strength. 
It will challenge you. It will teach you a new way of thinking, and a new way of riding. You can take your riding to an exciting new level!  

We use a variety of proven drills and training techniques. 
Practicing these techniques with our Yamaha dirt track trainers will enhance your abilities both on the track or the street.  

It doesn't matter what you ride or race, the Rich Oliver Mystery School improves everyone's skill level and mindset!

Factory Pro Spring Special!

Book a sightseeing flight over the Wine Country or a Kamikaze aerobatic flight or a biplane flight over Infineon Raceway, the Golden Gate Bridge and the San Francisco Bay for one or two during the spring and get a free souvenir t shirt!
(NEW!  Ask about the P-40 flights!)

707 938 2444

Just say that you saw this on the Factory Pro website!

Northern California's most unforgettable flying experience.  No experience required.  Open weekends!

Artisan Crafted Fine Cheeses – Since 1865       

Specializing in Handmade Brie & Camembert

Marin French Cheese Co., also known as The Cheese Factory and Rouge et Noir is not just the oldest cheese manufacturer in the country, but a vacationers and day trippers destination as well as a unique part of American History. Located north of San Francisco, east of Napa County, west of Pt. Reyes and Olema and south of Sonoma County, Marin French has produced hand crafted Artisan soft ripened cheese since 1865. Rouge et Noir cheeses are similar to French and European varieties but reflect the characteristics of Northern California, producing it's own regional style.


The extension of the laboratory for engines of the Swiss Federal Institute of Technology was completed in about 1935. Its architect was Rudolf Otto Salvisberg (1882-1940). He had a successful career in Berlin but returned to Switzerland after the advent of the Nazis. His architectural style was somewhat similar to that of Erich Mendelsohn. The staircase of the laboratory is in normal use but well preserved.
Edited to the tunes of Chemical Residue by Herbie Hancock.

Maybe in next rewrite, he'll fix the ignition timing and dyno chapters...
Otherwise great book with great starting ideas.

My bible

The little blue bible for quick references and little known facts.