Bigger Bore Using Stock Cylinder?
#1
#3
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I think you can go up to a 103.
I have a 102mm bore (stock is 100mm). It is a strong bike (especially with a race head (similar to Ron Wood stage III).
The 720 with the same head work is stronger on the hill. But, I think it becomes more of a weight issue at that point. If you weigh 175 and you're on a 680 and you go up against a 225 lb. guy on a 720 you will take him up a hill (Nothing positive or negative about either engine just that weight is an issue. . . )
Things to consider before doing this modification - head gasket / head seal - the 680 has had NO issues, the 720's seem to have their issues worked out - just talk with the right people before doing the job.)
How much extra power do I want - again, the 720 (105mm bore) is more powerful (I would guess about 3-4 HP???)
What kind of cams are you looking to put on?
I have a 102mm bore (stock is 100mm). It is a strong bike (especially with a race head (similar to Ron Wood stage III).
The 720 with the same head work is stronger on the hill. But, I think it becomes more of a weight issue at that point. If you weigh 175 and you're on a 680 and you go up against a 225 lb. guy on a 720 you will take him up a hill (Nothing positive or negative about either engine just that weight is an issue. . . )
Things to consider before doing this modification - head gasket / head seal - the 680 has had NO issues, the 720's seem to have their issues worked out - just talk with the right people before doing the job.)
How much extra power do I want - again, the 720 (105mm bore) is more powerful (I would guess about 3-4 HP???)
What kind of cams are you looking to put on?
#4
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Thanks for the info. After talking with both TheBom and Mr.Horsepower I've decided to go with Mr.Horsepower's newly designed 16:1 piston and A1/A2 cams on alky. Porting and larger valves will have to wait until I get a raise or I win the lottery. The 16:1 piston will support .450 lift cams as will the newly designed 14:1.
JMiller
JMiller
#6
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Jay dude, YOU SUCK!...LOL
Gotta beat me to the punch dont ya???
Should have come out to the atv rodeo bro...great time there. About 51 bikes showed up and I ended up taking second again..[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]
Gotta beat me to the punch dont ya???
Should have come out to the atv rodeo bro...great time there. About 51 bikes showed up and I ended up taking second again..[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]
#7
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Gotta beat me to the punch dont ya???
I bet the rodeo was a good time. Good job on 2nd place. What/who took first? Next year I'm going to attend more events around the country.
JMiller
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Logan Collins
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