registered user Posted January 20, 2013 Report Posted January 20, 2013 dude on another site said he has a genius idea how to put a simple PV on the 421 cub because aparently theres a flat spot at 5k rpm or so he says. dont cubs spend most of their time well above 5k rpm ? mostly for drag racing is what i thought the cubs purpose was. wouldnt a lower exh roof screw up the blowdown ? ive never seen a cub first hand so im just guessing with the transfers where they are it wouldnt run well with the exh lowered. just trying to make sense of what that knucklehead is saying. said every 2stroke works its best at 188/130 then you tune for the desired power with changes in the pipe Quote
Nightmare Posted January 20, 2013 Report Posted January 20, 2013 Huh Sent from my SGH-T679 using Tapatalk 2 Quote
registered user Posted January 20, 2013 Author Report Posted January 20, 2013 http://ktmtalk.com/index.php?showtopic=468458&st=30 ktm site. have to be a member to see it. this is what he says Secondly I am just finalizing designs for a bolt on 'powervalve' which can be adapted to most non PV two stroke engines.the first test will be on a 421 Cub (big bore/stroker banshee with CPI race cylinder) as it has an enormous flat spot at 5000rpm.Removing that flat spot without hurting the top end will make the bike not only easier to ride but it will also be a very popular commercial product.You haven't read about it because I don't want anyone stealing my idea as its so simple. Quote
dirtydownunder Posted January 20, 2013 Report Posted January 20, 2013 so hes gonna port his 421 cub to 188/130 he must be pretty good. Quote
WINDYCITYJOHN400 Posted January 21, 2013 Report Posted January 21, 2013 Bolt on power valves?.....Boy, you match that up with a boost bottle and your really going to be on to something........ You know why cubs have a big flat spot at 5000RPM?......cause the dipshit that said that doesn't have any idea what he's talking about. Quote
registered user Posted January 21, 2013 Author Report Posted January 21, 2013 i still cant imagine what a bolt on powervalve will look like. doesnt sound like hes gonna post any pictures Quote
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