Has anyone Overbored their F3? Wiseco makes a overbore kit for the F3....(wiseco.com)

.....i was just wondering if it would be that noticable of a difference in HP. The kit brings the F3 from 599cc to 637cc......."38cc more." (a 2mm oversize stock)

.....anyone know what that would roughly equalto in HP gains??

 

ever rode a 636?? But yea that should give a very noticable power gain, esp lower rpm torque.

 

Big bore kits FTW!

Yeah it'll be a nice difference. Go for it, you can do it!

 

My mechanic who use to race F2s and F3s said with Port and Polish and big bore kits he was getting 110hp to the wheel with dyno tunes.

But that sounds like a lot of money to dump into a F3. By the end(After a few hours of Dynotuning at $200-300 an hour)of ityou probably could have sold your F3 and got a decent used600rr which will have roughly 110hp to the wheel with much better handling and Fuel Injection.

But I've toyed with the idea. All I'm going to do is lean my jets out which will get my horsepower to mid80s-low90s since it's running way rich. Right now on a Factory Pro dyno I get 77hp at 13k and 34ft/lbs at 11k. Yet I let my buddy who use to own the bike ride it and it still had enough power for him to do this...
http://www.youtube.com/watch?v=L5HTtHHxjew

 

Huffdaddy?

That's with oxgenated race fuel,cams tweaked to "peak horsepower" only available at the top of the rpm range,flatslide carbs (which are a bitch to get right ) and on a standard dyno, not with eddy-current correction (5-6hp high) .

Mine makes 102hp with a paper filter and pump gas.My cams are set for grunt,not peak horsepower.KWS does good work

2 mil over is nice,but you have to split the cases,and it may cost you from 2.5k and up to 5k.Cheaper to find one that's already done. Go to a Legends race and ask around.

Yeah,it does make a difference,but to give you an accurate answer you're going to have to be more specific as to what you want,or mean by "difference in power".

May be cheaper to put in an F4 motor instead.

 

You do realize the f2 stock puts out 100hp and f3 puts out 104hp. So with a big bore kit the f2 would give around 111hp tuned right. And the f3 about 115hp. do a stage 8 jet kit and could rock 120ish. Would be nasty on straight aways.. and handle those tight curses. Love my F2!!

 

You do realise you've replied to a 14yr old thread.

I'm not sure if the bhp to bore gains are even that significant but i guess thats close if 599 to 637 is about 6% and if bore size gain is equal to power/torque gain. Stock F2 is lucky to make 90 and a good f3 might make a spot over 95. You'd expect a good 637 f3 to make about 100 set up right, maybe mid to high 100s with cams, a bit of headwork, the right exhaust and total loss. Cant imagine seeing one near 120 without some seriously lightened internals, blueprinted, knife edged crank etc and an fi conversion unless it was a very optimistic dyno but i'd happily be wrong. Couldnt imagine it being much use for anything but playing straightline hero either. All speculative of course.

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