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2 stroke porn

Posted: Wed Jul 30, 2008 7:04 pm
by zimm
isnt this just lovely ?

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if i could spare the cash i'd have it just to look at.

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 8:04 pm
by RedexRobB
Not sure what it is if im honest, something tells me its a Yamaha. Ahh looked carefully and saw the 'yamaha corse' badges :)

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 8:27 pm
by crushedlizard
That's a 250cc right? Where are the exhausts/spannies though? :smt017

It is a lovely bike. I struggle with anything but USD forks though - old style look like knee-high socks

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 8:28 pm
by RedexRobB
i suspect they exit out the back and are hid underneath the seat panels.

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 8:55 pm
by zimm
its a yamaha TZR-250 3MA reverse cylinder,

its a parallel twin with the carbs in front of the cylinders and the exhausts exiting in a straight line under the seat, very very closely related to the tz-250 gp bike of a couple of years before

60bhp, 50% more torque than a zxr400, 135kg

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:smt007 :smt007 :smt007

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 9:17 pm
by RedexRobB
60bhp, 50% more torque than a zxr400, 135kg
Bloody hell, that thing must be lethal!

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 9:38 pm
by crushedlizard
I was wondering how you could squeeze an expansion chamber under the bike and get away with extending the pipe. That is such a cunning way to mount the engine/exhausts.
I'm probably being really stupid here, but how do you reverse the engine? Or has the engine always been orientated with exhaust ports to the rear?
I know in theory 2T engines can be run in reverse but I thought that applied to very simple models.

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 9:55 pm
by zimm
crushedlizard wrote: I'm probably being really stupid here, but how do you reverse the engine? Or has the engine always been orientated with exhaust ports to the rear?
its just the cylinders that are "reversed" mostly strokers are a normal configuration, but the 3MA was the most developed parallel twin made, by the time it was launched everything else was a V twin (KR1-S doesnt count as it was an evolution of the KR1 which was already a couple of years old)

i believe yamaha did it for a number of reasons, exhaust packaging being the obvious one, and primitive ram-air the next (although only on the TZ's, the airflow on the 3MA is a bit convoluted)

Re: 2 stroke porn

Posted: Wed Jul 30, 2008 10:00 pm
by zimm
RedexRobB wrote:
60bhp, 50% more torque than a zxr400, 135kg
Bloody hell, that thing must be lethal!
aprillia rs250 would be quicker, but i know which i'd rather have :smt002

Re: 2 stroke porn

Posted: Thu Jul 31, 2008 12:02 am
by Scott221
I was so close to buying a tzr 125 last week. I mean just look at this...

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Re: 2 stroke porn

Posted: Thu Jul 31, 2008 12:12 am
by zimm
lovely arent they .. i think adamzxr(?) on here is selling his ..

tzr250 3xv v-twin (250 version of above)

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if they werent restricted to 45bhp (and almost impossible to de-restrict) and uber expensive (that ones on ebay for 4 grand !!) i'd most definitely have one

given the above, i want a 3ma

Re: 2 stroke porn

Posted: Thu Jul 31, 2008 1:41 am
by crushedlizard
zimm wrote:its just the cylinders that are "reversed"
Oh of course, you mean it's just the barrels that are rotated 180º (and I suppose pistons)? I think I remember someone wanting to do that on an Aprilia RS125 so they could have an underseat exhaust without choking all the power out by lengthening the pipe. But it couldn't be rotated for one reason or another.

Anyway, awesome setup. Where did you find the pics?

Re: 2 stroke porn

Posted: Thu Jul 31, 2008 3:43 am
by zimm
its on ebay for £1020 .... and im VERY tempted ...

anyone want to buy a couple of ZXR's so i'd have space ?

Re: 2 stroke porn

Posted: Thu Jul 31, 2008 9:19 am
by rene
when i finaly get my own space im going to fill it with 2 pokes. Most likely starting with a TZ250 :D. The engines just fit bikes so perfectly compaired to 4t's

Re: 2 stroke porn

Posted: Thu Jul 31, 2008 9:19 am
by Gemini