No, you will need race gas because you will need a fuckton of compression to make that kind of power out of a 650. Race gas isn't for making more power on a stock motor, it's because a superbike motor will not run on anything else. You could do some mild head work and swap cams on an EX650 and make a bit more power, but it's still going to get stomped by an old F2 or FZR600 that already makes 90 hp stock. So in reality you would have spent a ton of money to make a reliable bike less reliable and only slightly not as slow.
Its not always about having the faster bike, for some folks its about making more of what you have. Theres a long way between stock and supertwin spec... I think some more compression and hotter cams would yield the little up top boost the bike could use w/o turning the motor into a grenade
I honestly don't think an insurance company would go through the trouble of checking a bike for modifications , I think most insurance companies would just settle by paying the stock price and would not bother paying someone to look for modifications unless they are getting sued for a lot of money.
Lose control, hit a pedestrian, break his back, and if there are undeclared mods your insurer will be after you for money for the rest of your life. If it's just property they'll pay book value with nothing extra for the mods, but if injury is involved they take a different view,
Guys in Europe regularly get over 90 HP out of them, but that's a heavily reworked motor with aftermarket rods and pistons, polished knife edged crank, lots of head work, etc. Of course that's a race fuel only motor that is only good for about one season before a rebuild. In race trim a 650 and a 600 weigh about the same, the EX650 has a lot of heavy parts and other useless crap that can be replaced or removed.
I think 'regularly' is an exaggeration. Otherwise that's about right.
What's a knife edged crank?
Polished with all sharp edges removed and all corners radiussed is the norm to avoid stress points that might fracture under the loads of a tuned motor used flat out. Might be a different use of language?
Rods and pistons are similarly re-worked - even the aftermarket ones, and are balanced with each other and with the other moving parts to maximise reliability.
Race gas needs some care over the definition. High compression engines with aggressive ignition advance need high octane (98 - 100 RON) to prevent detonation that can destroy the engine. High octane fuel doesn't deliver more power but allows a high degree of tuning, as you said. Race gas formulated with a high oxygen content delivers more power. Not sure what your rules are on using that.
I think 'regularly' is an exaggeration. Otherwise that's about right.
What's a knife edged crank?
Polished with all sharp edges removed and all corners radiussed is the norm to avoid stress points that might fracture under the loads of a tuned motor used flat out. Might be a different use of language?
Rods and pistons are similarly re-worked - even the aftermarket ones, and are balanced with each other and with the other moving parts to maximise reliability.
Rob
Knife edging is when the counterweighted parts of the crank are ground on the edges to a pronounced V shape. Along with polishing it allows the oil to be easily flung off and reduces parasitic drag.
The image is tiny but you can make out what I mean:
Got you. We just tend not to use the term. We're also cautious about taking too much off the counterweights on a twin because they have more of a real job to do in balancing the reciprocating masses. Not as big an issue on a 180 degree twin as it is on a 360 degree unit.
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