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post #1 of 10 (permalink) Old 12-18-2001, 02:31 PM Thread Starter
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DR Big

Hey Grok (or anybody), are these officially imported into Canada? If they're readily available I'm thinking the motor would be ideal for a singles roadracing project. What kind of power do they make stock/modified?

Suck mean people!
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post #2 of 10 (permalink) Old 12-18-2001, 04:11 PM
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Not anymore. You might find a leftover somewhere, maybe send an email to suzuki Canada.
This is their website A few people have run the big doctor in road-racing, myself included.(check the endurance supermotard thread) Not sure of the power though.......anyone?

Try it...........You'll like it!
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post #3 of 10 (permalink) Old 12-19-2001, 02:02 AM
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As far as I know, only the DR750 made it to Canada in limited production in the late 80's.

The engine made roughly 50hp @ 6800 rpm, 40 lbs @ 5600 rpm. 9.5:1 compression, air cooled ....

Can you say KTM?
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post #4 of 10 (permalink) Old 12-19-2001, 02:31 AM
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Originally posted by KLRAdam

Can you say KTM?
Kay, Tee, Em. Yep.
post #5 of 10 (permalink) Old 12-19-2001, 02:47 AM
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Originally posted by Pete


Kay, Tee, Em. Yep.

LOL!

Seriously, I can give you a list of cheap mods to do the KTM 640 engine that will give you a little over 70hp and from what I heard the reliability isn't compromised.
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post #6 of 10 (permalink) Old 12-19-2001, 08:19 AM Thread Starter
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Not that I'll be taking on another project anytime soon, but I'd love to know how to take an LC4 from (maybe) 50HP to 70 without making it a rolling grenade???
I kind of figured any of the new generation 450cc+ diesels would trounce the old 2 valve DR, but the only one that has been out long enough to provide availble used motors is the YZF426. And those are still popular enough that they're probably not cheap.

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post #7 of 10 (permalink) Old 12-20-2001, 01:09 AM
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First off, I have to back peddle a bit. I thought it was the 640 engine but it's the KTM 620 engine the article is referring to.
Since they are pretty similar I'm sure most of the mod's should work or there is info out there for the 640 engine.




Duke I Article ...
Stolen from http://www.perardua.net/thumper/articles/dukefaq.html

"With a few reasonable modifications the Duke can hold its own with F3's, ZX's and FZR's. The engine is very understressed in stock form, with the following mods the engine will produce over 70 HP at the rear wheel. Drop one tooth on the countershaft sprocket, install a MegaCycle TT grind cam, either install a 11:1 piston (Cosworth) or have the head milled for a 11:1 CR, Port and polish the head, .5mm larger valves, Malcom Smith competition stainless steel exhaust with 6 supertrap discs and a White Bros billet 'snuff or not' end cap, throw away the Quick Silver II carb and replace with a 40mm Dell'Orto carb from a KTM 620 EXC(Email me for details on carb set up).. These mods will cost around $1,000 and will produce over 70HP. Now for the suspension; install a Race Tech gold valve in the forks, use 1mm less oil, have the shock revalved for softer initial compression, set the sag at 3.75 inches (200 lb rider), install good DOT race rubber, such as Dunlop SportmaxII , Pirelli Dragons, Metzler MEZ 1. In the stock sizes, air pressure 36 front, 40 rear. The brakes are fantastic in stock form. I have cut the pad width by half on the rear brake because it tends to lock up very easy."
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post #8 of 10 (permalink) Old 12-20-2001, 03:37 AM
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Quote:
Originally posted by Tristan
I kind of figured any of the new generation 450cc+ diesels would trounce the old 2 valve DR, but the only one that has been out long enough to provide availble used motors is the YZF426.
The DR was 4 valve and it was the choice of many for the SOS races (sound of singles).
This girl here used the DR engine to win the 1998 European Supermono Championship, so this engine surely must have the potential!

You know who she is

Aris
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post #9 of 10 (permalink) Old 12-20-2001, 09:12 AM Thread Starter
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Thanks Aris!
And Adam, I have to question a guy who starts out with "Drop one tooth on the countershaft sprocket". That may help acceleration, but won't do a damn thing for HP. And the rest of those mods sound a little intensive. I'm way too lazy to do motor rebuilds once or twice a season. That's why I'm racing an SV and not a 2 stroke right now.

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post #10 of 10 (permalink) Old 12-21-2001, 01:26 AM
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Quote:
Originally posted by Tristan
And Adam, I have to question a guy who starts out with "Drop one tooth on the countershaft sprocket". That may help acceleration, but won't do a damn thing for HP.
Of course it will! The aftermarket sprockets are lighter and you save at least an ounce in weight. This allows the power to spool up much much quicker!

I'm surprised you didn't catch on to that one.
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