Saturday, November 23, 2019

TW200 full exhaust pipe prototype.

Down style full exhaust pipe build.

not detail finish yet but it's set up like photo.

↓and how sounds like↓


Saturday, June 29, 2019

Yamaha TW owner's meeting in Japan.

Yamaha TW125/200/225 owner's meeting in Japan 2019 


Date:       Sept 28, 2019.  1:30pm~ about 4:30pm
Location:  Yamaha communication plaza parking.
                (Address: 2500 Shingai, Iwata-shi, Shizuoka-ken 438-0025, Japan )

               Free entry.

Link of Yamaha communication plaza here.

Over 30 years of manufacturing without big model change, TW is keeping on sale all over the world. That is so rare compared with any other motorcycle model. We going to celebrate this long sale and meet up at TW's home of birth!

Please comment if you have any question or email to furuhashiracing"at"

Thursday, June 15, 2017

Dunlop K180 Available in US!

Dunlop K180 Available in US finally and we just got front and rear tire set from Westfield Powersports !

Furuhashi Racing want to say big thank you to Suzuki motorcycle USA!

This tire is original equip for SUZUKI VANVAN200 (RV200). You can purchase this Dunlop K180 tire from Suzuki parts dealer.

Suzuki Parts Number:

Front: 55110-13G10 (Size 130/80/18)

Rear : 65110-13G10 (Size 180/80/14)

Retail price F:$195.86 R:$187.51
(*Check your local Suzuki dealer for price.)

Tuesday, September 20, 2016



2001 HONDA XR100 $900.

Dunlop GT501F is on rear wheel. Price include spare rear wheel w nobby tire. 

2006 HONDA CRF100 $1400

Female rider owned and not much ridden.  
Everything very clean.

Both bike has stock motor. Good running condition. Locate in Indianapolis, IN
Bike maintenance and WPC Treatment also available  ( with additional price.)

If you have interest, Please email to Koji.

Sunday, August 28, 2016

Back from hibernation.

We have so much rain this August in Indy. Race has been cancel many times by bad weather. This Saturday was also. 

Complete shape back.

We put this Yamaha back together to running condition. This flat track modified YZ450F has very nice Jemco exhaust pipe. 

Pipe end diameter is about 4"

Guess who forgot to remove pipe end cap and trying kick start..?

Cap fly away there.

The cap flying distance shows this bike has pretty good compression.

Have a nice day.

Sunday, July 24, 2016

Mikuni TMR project

All information in this article is not for the amateur or person who is inexperienced at motor work. This is not a tuning manual. Motor work has many kinds of risk and motorcycles can cause you serious injure or death. Take your own risk and responsibility if you attempt to work or to ride. We hope we can leave this article open public for enthusiast. Thank you.

 We apologize about took so long from last up date.

Now, Furuhashi Racing's FTW (we calling our TW like this way) project is keep on going!

We decided install Mikuni TMR carburetor this season.

Mikuni TMR carbretor is racing use only and never sold in US market somehow. 
This pumper carb can make nice throttle response and power feeling to bike.

Koji kept this carb for many years in his garage. 28mm diameter is perfect size for TW200 stock displacement.   

This sound made us lean into it.

For fitting:

This carburetor require couple of modification for install to TW. Most issue are Interference with frame and rear shock.

1st: Throttle wire holder. 

TMR stock angle and position.

Yoshimura TMR

Throttle wire needs more slunt angle for fit. This parts release from Yoshimura Japan.

2nd: Rear shock and carburetor, air filter fitting.

Standard intake manifold mount.
Flip upside down. 

We can fit in after intake manifold 180 degree upside down. 

But there is no space for air filter or filter connecting.

This idea is only work for funnel version like this photo. 

"Air filter is necessary for dirt track racing use."


We decided to go to standard intake manifold by original equip angle after many try and error.

Grind off frame and carburetor throttle wire holder just little bitt for made clearance.

 Shorten spigot by lathe would make more space between carb and frame.

Cut and weld 180 degree bend mandrel aluminum tube for make air filter joint.

roll up aluminum sheet metal for joint part and weld together.

Check fitting

checking clearance between rear shock spring. This tight clearance would not see typically street or dirt bike.

Original Idle adjust screw (right side in photo.) has interference with rear shock spring. We put left side one to carb. This piece has long thread length that needed to shorten.

This is how fit looks like. K&N filter stick out from side.  

Side cover will not fit together so, we decided intake tube curve back to inside.

Final shape.

Side cover can stay now.

Adjust carb jetting few and put back together.

3rd: Electric wire and components.

We took off air cleaner box so, Electric components has to be sit some place. 

We made this panel from aluminum sheet metal.

 Fit perfect! (This wire harness is only for racing use. )

Rear fender is totally gone after air cleaner box off so, we made simple & light weight  rear fender by fiber glass sheet. Strong and flexible too.

It's time to ride. 


Koji take this machine to Mid-America Speedway other day.

His Impression:
"Fun, fun and fun. Power feel is big changed. I can tell it has much more power than before. This effect from total tuning so, not only by pumper carburetor. I am not sure how much weight air cleaner box had but bike feel so much lighter and I didn't feel rear wheel mass weight like last I rode here. Race track is little too dry and slipply but now, rear tire making power slide by my throttle control. That couldn't happen before. This bike is totally different from street model.  People judge motorcycle by displacement and spec these days. FTW is street model base air cooled 200cc motor. Maybe some people think "Young donkey"  but I can not tell that way anymore. It just great and fun to ride on dirt track! "

"At main race after sunset, track was packed well by nice moisture down into soil. that meaning we can get really smooth grip like asphalt.  FTW runs well as heat race. I wouldn't say power sliding was exact same as heat race track condition but this power feeling is real. I could really enjoyed race and finished 1st place in mad dog class. I'm trying to make simple expression, this bike just so much fun!"


Furuhashi Racing thanks to : Mid-America Speedway

We service TW/TTR motor maintenance / tuning up and deal WPC treatment in midwest area. Email us if you have interest.

 KFR original big Exhaust valve for sale : eBay link here.

Thursday, November 26, 2015

Thank you for 2015 season.


Thank you for all your support in 2015 season!

"FTW" won mad dog class on 2015 Mid-America speedway race series!

Furuhashi Racing original exhaust valve proven great performance!

@Frankfort half mile. (Please click picture to see photo)

Photo from 520 chain cafe

Full throttle 1/2 mile run at Frankfort, IN

Koji Furuhashi Racing thank you to:
Arai Helmet, BLUETAG, CP Pistons, Durelle Racing, G2 ergonomics, Kadoya, Kersting's Musium, Native eyewear, Redstone Performance Engineering, Racetech,  Rebel Gears, SEV, Smith moto goggle, Sudco, Webcam, Westfield power sports, WPC Treatment USA,  (ABC)