Bike currently at JHP having the 853cc engine fitted that i bought from Cookster. Thankfully the swingarm pivot bolt came out without any issue.
Had the bike for 7 years this year. Longest i have kept any bike by some length. Toyed with selling off and on but this gives me the chance to make something really special (to me) and track it occasionally too.
I had an 748R tuned by Biggelaar in the NL that put out 125 Rwhp... so an 853 should get a lot more than 119.... specially with R heads.....
I expect JHP's dyno to indicate a healthy figure . My 748RS based EVR 853 was dyno'ed at 133 rwhp and just under 70 lbf ft. Anything around the 125 rwhp mark will be great fun. From my perspective it's nice to have the extra perfomance but the real bonus with the 853 conversion is just how freely it revs and how quickly you accelerate out of the bends which is as addictive as any drug. Andy
I noticed with mine, the extra torque low down and the power doesn't appear to drop off at the top end. Steve
Guys don't forget that the engine duke is on about started as a standard bp motor not and R. Standard bhp on a bp engine is about 95. I doubt you'd get much more with standard heads and valves.
There ported different, have bigger valves and use different cams make more power but are very peaky.
What cookster said. Bigger valves so better breathing and depending on the 853 kit used, there are high compression pistons available. Not too sure I'd agree with peaky though as mine is very smooth. Torque curve is quite flat from about 7000rpm and power is almost straight line up to 12000rpm. Andy
A few problems with it at the moment as coolant is leaking into the engine somehow when it gets very warm. That aside its a cracking engine and the few sessions i had at Silverstone it worked very well.
