RD 250 - known issues?

[inlinefour]

U guys should remeber the RZ 250 The first road version had one a alot of years back it was cool first true 100 mph 250 in mid eightly also haved a rd 350 lc what a wheelie machine

And it was good for going slightly sideways around sticky courners (generally without crapping off)

[Jantar]

U guys should remeber the RZ 250 The first road version had one a alot of years back it was cool first true 100 mph 250 in mid eightly also haved a rd 350 lc what a wheelie machine

I think you are showing how young you are. The first genuine 100 MPH 250 cc machine was the 1971 Suzuki T250 road tested at 105 MPH, (though there are some who claim its predecessor X7 was equally as quick). The 1973 Yamaha RD250 handled better and accellerated up to 100 MPH quicker, but was road tested to top out at 103 MPH.
The Kawasaki S1 had a claimed top speed of 110 MPH, but the only one i ever rode, and all road tests I've read put the true top speed at exactly 100 MPH.

Yep the RZ250 was a genuine 100+MPH bike, but not the first.

[moko]

I think you are showing how young you are. The first genuine 100 MPH 250 cc machine was the 1971 Suzuki T250 road tested at 105 MPH, (though there are some who claim its predecessor X7 was equally as quick).

Older road-tests are definately suspect,they were rarely objective with manufacturers expecting a good write-up or threatening to pull the plug if they didn`t get it.Kawasaki actually black-listed Superbike back in the 70`s for criticising the handling of one of their bikes.About the same time BIKE took them on and said if they didnt supply bikes to them then they`d test whatever they could lay their hands on and tell it like it is.Bike companies came to the conclusion that supplying test bikes themselves that were properly prepped e.t.c. made more sense.Honda and Kawasaki have been rumbled for supplying non-standard machines to road-testers in the past,one ex-press fleet GPZ900 got disqualified from a proddy race for having an illegal camshaft,accusations flying all over the place on that one.
X7 came out in about 1979 and definately wasn`t the T250`s predecessor.With hindsight it`s recognised by the bike press as the first GENUINE 100m.p.h. 250.Older 250`s may well show a ton on the speedo but that`s about it,at least in standard trim."World`s first 100m.p.h. 250" was a claim just about every 2-stroke 250 made when it was launched back in the 70`s,in reality most would do 95 or so on the road.Even the X7 figure was a roadtester on a track wearing leathers with his head down over the clocks and the mirrors taken off but it cracked it nonetheless.250LC was a brilliant bike,not only was it very quick for it`s day but it`s also a lot more of an all-rounder than many suspect,I used mine in heavy trafic to get to and from work apart from fun stuff and it made a brilliant commuter,of course mine was standard and most bunged on expansions and lost all the bottom end.

[Jantar]

X7 came out in about 1979 and definately wasn`t the T250`s predecessor.With hindsight it`s recognised by the bike press as the first GENUINE 100m.p.h. 250.Older 250`s may well show a ton on the speedo but that`s about it,at least in standard trim."World`s first 100m.p.h. 250" was a claim just about every 2-stroke 250 made when it was launched back in the 70`s,in reality most would do 95 or so on the road.. .

In 1965 Suzuki released the "Hustler "Depending on where it was released it was also called the X6 or the T20. It produced 29 BHP and was rated at 95 MPH. The model continued on with developement through 1966, and in 1967 it changed to the T21 or X7, again depending on which market it was designed for. You are right in that an X7 was again released in 1979, but by then it didn't bear much resemblance to the 1967 model. The T250 had a claimed ouput of 33 BHP, and the GT250R was supposed to be 35 BHP. I believe that claim to be somewhat optimistic. Suzuki kept the name "Hustler" right through its 250 cc twin range.

I raced both the T250 in production racing and a TR250 in racing class. As you are aware, in production racing nothing is done to the motor other than ensuring that it is in a very good state of tune. In a straight line on the T250 I achieved a standing 1/4 time of 15.9 seconds and a flying 1/4 of 101 MPH at School Rd, Mosgiel. The bike was still accellerating (albeit very slightly) as I entered the traps and the true terminal speed would have been fractionally higher.

[moko]

A case of different model designation for different markets then.Only X7 we got was the 79 bike.(plus X5 200 and X1 50).All ram-air 250`s here were badged and sold as GT250`s.
There was alot of debate here about "the first genuine 100 m.p.h. 250" and the agreed criteria amongst the press was totally standard regarding gearing,bars e.t.c. and the 79 X7 was the first to crack it.It also had a rep for seizing and having a bendy frame un-like the preceding GT250A which was faster than an RD but just as tough.