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crowboy15

720 big bore kit

11 posts in this topic

has anyone heard of a 720 big bore kit seems like i saw one these in dirt bike magazine several years ago any imformation will be appreciated :D

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There's no way the cylinder is thick enough to go that big. 680cc is already getting pretty thin. Maybe with a stroker crank, but then I think it would be very slow-revving. The 680 already makes TONS of torque- any more would be overkill, IMO.

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i think it was a new cylinder that i seen (very expensive like 2000 bux) that was made to 720. i think just a high compression piston, exhause, carb, and what not is good enough.

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yeah BD had 710 kits--so did a german motard outfit...

having done the 680 mod--i am a big fan of more...i do know of one guy who had issues with the 710 at Vegas to Reno 3 years ago...might want to go easy on the compression.

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A place called LA Sleeve did (still do?) a 720 kit for the 650L. It was tested in the January 1998 issue of Dirt Bike. Back then the kit cost $350 (piston kit, gaskets, and sleeve) and machine work was $305 (had to machine the cylinder & cases). HP went from 34.6 to 41.4 (no other mods were done on the test bike).

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They didn't give any #'s on torque which seems really strange. You'd think the torque would be impressive as well...

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