TA250 Motor

[EE]

Yeah best advise if you want to go dry clutch in this situation would be sell the TA engine, use an Rd engine as your base, and buy the TZ dry clutch cover from fondseca that has the kickstarter mount and the special longer mainshaft that lets you use an RD400 gear set. Ed

[Jspooner]

Yeah best advise if you want to go dry clutch in this situation would be sell the TA engine, use an Rd engine as your base, and buy the TZ dry clutch cover from fondseca that has the kickstarter mount and the special longer mainshaft that lets you use an RD400 gear set. Ed

And then put a TZ 750 (375) top end on it...........

[Yamaha 179]

Ed and Joe said it all.  That would be the smartest, most effective, most affordable and easiest way to accomplish what you want to do.
Lyn Garland

[EE]

I talked to Vince at Fondseca today and he said 3 of those kits have come to the US so theres a couple people over here getting dry clutches.. real nice kits. Ed

[bitzz]

And then put a TZ 750 (375) top end on it...........
[/quote]

...then he would need an unobtainium TZ water pump.
Better off with air cooled, reed valved RD400 top end. TZ pistons and rings, and chrome cylinder liners, are pretty rare and spendy.
... still doesn't get over the nine mile long first gear and no kick starter.

I still think OP should sell it to me... cheap. I am trying to rebuild Dave Hughe's " world's fastest aircooled two stroke". A TR3 that was clocked at 154MPH at Daytona, that was last ridden by Michelle Duff. I have the bike, need motor stuff. I have a late model TZ bottom end, but really want an early, and a 350 gear set would be nice....
Anyone have a TZ 350 primary gear set they want to sell? I have a NOS 250 set, or NOS or good used TZ cylinders and pistons or cranks (early and late) to trade.

[m in sc]

actually you can use an electric water pump as well. been there, done it.   

[teazer]

The TDs and earlier had vertically split cases... and the clutch on the end of the crank
The TA125/250s and the TR3 have the first horizontally split cases, with the clutch on the transmission input shaft, thereby spinning at a third of crankshaft RPM, making almost everything more better. That clutch would weigh a literal tonne at 10,000 RPM.
... then Don Emde won the Daytona.

TD1 and 2 were very different motors - agreed. TD3 and TR3 were basically the same motor with different barrels (pistons and heads) and primary drive.  TZ's were just water cooled TD/TR3 until they went all back to front and reed valve etc in about 1981.

The only parts of that motor that would be suitable for street use are the crankcases.  You could use a dry clutch conversion and that air cooled clutch but that would be a bit of a waste.

Make a TD3 out of it and race it or sell it an use the funds to build what you want.

[teazer]

actually you can use an electric water pump as well. been there, done it.   

Absolutely.  Bosch do an electric pump for VW/Audi that is fine and can be hooked up to a thermo switch.

[Diablo007]

As mentioned earlier in the thread.  I'm open to offers on the motor.

From what I'm gathering it's not a common motor and has some trick pieces on it, so I doubt 'cheap' is going to happen.  Then again, my version of cheap and yours may be completely different.  PM me if anyone is interested.

BTW, I was under the impression that the early TZ250 and TZ350 had the same bottom end?  There's a TZ250/350 in the shop, found the 250 top end for it in a box with the motors.

[Diablo007]

Found the owner's manual.  Amazing what's still in boxes from the move to this shop.

[EE]

That is too cool!! Does it have a date in it? 73 or?

[Diablo007]

BTW, move to this shop was about 20 years ago, the box probably from the move before that judging by the other manuals and such in it.

Date is '73

[EE]

"I still think OP should sell it to me... cheap. I am trying to rebuild Dave Hughe's " world's fastest aircooled two stroke". A TR3 that was clocked at 154MPH at Daytona, that was last ridden by Michelle Duff. I have the bike, need motor stuff. I have a late model TZ bottom end, but really want an early, and a 350 gear set would be nice...."

Just a correction as far as i know the worlds fastest aircooled two stroke record was set by that Ed Erlenbach guy on his RD400 landspeed bike:

164.736 w/fairing
159.115 without fairing Muroc
156.925 without fairing El Mirage

http://erlenbachracing.co/landspeed.htm

I know it's the fastest aircooled two stroke twin.. i don't know if the aircooled triple guys went any faster?? Ed