Blaster History

Home of the IT 200
Yamaha Australias WR200 Page
Paul Quale's IT200 Page

As you may know, the Blaster motor has been with Yamaha for a long time. I belive the first version was in a Dirtbike called the IT 175. The 175 was availiable from 1977-1983, when it was upgraded to a 200.

The DT175 was also imported to the US from 1974-1981, as was the MX175. I belive it shared a motor with the the IT 175. The DT 175 is still produced for the Australian market.

A nice action shot of someone testing out the 1999 Australian market DT175

A 1995 (I think) DT175

Another 1999 DT175, this bike is also part of Yamaha's International Aid Program.

"The Yamaha IT-200 was created in 1984 as an effort to take control of the new 200 cc enduro class. Although it was an out-growth of the IT-175 in concept, the IT-200 was entirely new. It's competition was limited mostly to the Kawasaki KDX-200, and the Honda XR-200. IT 200's were available as 1984, 1985, and 1986 models. The only difference between these three models is that the 1986 model got a spiffy front disk brake, and lost fork compression dampening adjustment (which the earlier two years had). All three years wore the same sky blue bodywork, although the gas tank stickers varied slightly."

Above: A blurry photo of the IT200.

This motor (IT200) is basicly the one the Blaster uses. The only differences are the carb sizes, (IT is 8mm larger) the IT uses a "boost bottle" and the Blaster has more torque, but less horsepower.

Above: A picture of the IT200s "boost bottle." I apologize for the low quality.

Later this motor was coverted to water cooling, and gained a powervalve in the WR200, and the DT 200. The WR200, was only imported to the US between 1991 and 1993.

Above: A picture of the Australian market 1999 WR200.

In theory, the clyinder, head and water pump from this motor would just "bolt-on" to a Blaster bottom end. The WR/DT water pumper motor does NOT use the same cases as the Blaster, you can see that in the above picture. They do, however, share internal motor parts with the Blaster.

Yamaha recently upgraded the WR/DT200 motor. Here is some info from Yamaha's site, on the DT225.

"The DT's 224cc liquid-cooled, power valve-equipped two stroke engine is developed from the proven DT200 powerplant, only with stronger power, smoother power...better power... Most bikes start easily if you know the technique, and the DT230 technique is to push the thumb button - it's the first two-stroke dirt bike to feature both traction control and electric starting."

Yamaha doesn't have specs on this bike, but it does have specs on the bike it was derived from, the DT200. This bike (DT200) has the same bore/stroke and cc's as the Blaster, but only a 6.4:1 (the Blaster is 6.7:1) compression. How about this: a 224cc water cooled, electric start Blaster with 3D ignition. Not possible, but we can dream can't we...

I also found out Yamaha still makes the DT175 (similar to the IT 175). The DT has DT a 6.7:1 compresson, and a 7mm shorter stoke as compared to the Blaster.

As you can see the Blaster is a very old engine. Whenit was new it was high tech, but the motor family has gotten few upgrades (with the exception of the WR200, DT200, and DT225) and is now more of a low tech motor.

Below is a chart showing the specs for the Blaster (left) DT175 (center, this motor is the same as it was in 1974) and WR200 (right).

Engine	Blaster	DT175	WR200
Type	2-stroke, air cooled, single	2-stroke, air cooled, single	2 stroke, liquid cooled single, powervalve
Displacement	195.0cc	171.0cc	199.7cc
Bore x Stroke	66.0 x 57.0mm	66.0 x 50.0mm	66.8 x 57mm
Corrected Compression Ratio	6.6:1	6.7:1	6.3:1
Lubrication	Autolube	Autolube	Pre-Mix
Carb.	Mikuni VM26SS	Mikuni V25	Mikuni TM30SS
Starter	Kick	Kick	Kick
Trans/Final Drive	6-speed/Chain	6-speed/Chain	6-speed/Chain

Interesting isn't it? Does anyone else have any info?

Email: rockosmith@aol.com