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How much difference will a big bore make on my setup?

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I have a 2013 DRZ

 

3x3

MRD/SSW

39FCR 

Hot Cams stage 1 in/exh

 

 

What should I expect when I do the big bore? Is it going to be a WOW change? Or just another incremental change? 

 

I would imagine a lot more TQ in the low end and mid range? How much of a higher RPM difference?

 

Basically overall, is this going to be a change that transforms the bike the way the exhaust/carb did?

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I have a 2013 DRZ

 

3x3

MRD/SSW

39FCR 

Hot Cams stage 1 in/exh

 

 

What should I expect when I do the big bore? Is it going to be a WOW change? Or just another incremental change? 

 

I would imagine a lot more TQ in the low end and mid range? How much of a higher RPM difference?

 

Basically overall, is this going to be a change that transforms the bike the way the exhaust/carb did?

 

Yep.....Yep.....and Yep   You're gonna love it!

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Yep.....Yep.....and Yep   You're gonna love it!

Nice! I can't wait. It shipped today supposedly. 

 

I think I am going to get a Hot Cams stage 2 intake cam eventually, but for now the stage 1's will have to do. I am sure with the extra displacement they will be worlds better than stock anyway. 

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Nice! I can't wait. It shipped today supposedly. 

 

I think I am going to get a Hot Cams stage 2 intake cam eventually, but for now the stage 1's will have to do. I am sure with the extra displacement they will be worlds better than stock anyway. 

Which BB kit did you get?

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The difference will be similer to when you added a fcr carb. Lots more bottom and midrange power. Top end suffers a bit but once broken in it won't really be noticeable

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The difference will be similer to when you added a fcr carb. Lots more bottom and midrange power. Top end suffers a bit but once broken in it won't really be noticeable

If top end suffers some,  but you are getting more bottom end,  can you go down a couple of teeth on the rear sprocket to make up for it?

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I went to a 14T front sproket, I can always put the 15 back on.  That would be nice for highway anyway.

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I went to a 14T front sproket, I can always put the 15 back on.  That would be nice for highway anyway.

 

with a 14 on the front you won't have to worry about front tire wear......probably never touch the ground now. ;)

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If top end suffers some, but you are getting more bottom end, can you go down a couple of teeth on the rear sprocket to make up for it?

bigbores don't like to rev high like the stock bore does. Dropping a couple of teeth on the back does make up for it
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My BBK seems to make the same or a bit more power up top, but the mid-range and bottom is so much better that I rarely rev it right out.

 

I think that most of that is related to the cams, exhaust and intake. With a set of aggressive cams, MRD and FCR41 it would likely gain quite a bit up top. However for how I ride it's just about right, I will probably spring for the WR trans one day.

 

-Grant

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My BBK seems to make the same or a bit more power up top, but the mid-range and bottom is so much better that I rarely rev it right out.

 

I think that most of that is related to the cams, exhaust and intake. With a set of aggressive cams, MRD and FCR41 it would likely gain quite a bit up top. However for how I ride it's just about right, I will probably spring for the WR trans one day.

 

-Grant

 

A 39 will be better everywhere except over 8,000 rpm...

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My BBK seems to make the same or a bit more power up top, but the mid-range and bottom is so much better that I rarely rev it right out.

 

I think that most of that is related to the cams, exhaust and intake. With a set of aggressive cams, MRD and FCR41 it would likely gain quite a bit up top. However for how I ride it's just about right, I will probably spring for the WR trans one day.

 

-Grant

Yeah , dead right :thumbsup:

It's win ~ win .. For you

The BB gives you more Torque , so .. You keep the Overall Revs down , this saves you flogging out the valves / Bottom end .

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Is my OEM cyl/piston worth anything? Its only got 5000 miles on it, regular oil changes, full synthetic since 2000 miles.    Someone out there has to need a new top end and can't afford a BB kit I figure.  

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Is my OEM cyl/piston worth anything? Its only got 5000 miles on it, regular oil changes, full synthetic since 2000 miles.    Someone out there has to need a new top end and can't afford a BB kit I figure.  

 

It wouldn't be worth a great deal......If you don't think you will use it you could place an add in the classifieds......

Edited by Craigo 485sm

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It wouldn't be worth a great deal......If you don't think you will use it you could place an add in the classifieds......

I was thinking about saving it for a buddy who has a DRZ with like 40k miles on it (Its TheGardensnake's old bike) and not much money.  In case his pops I can sell it to him cheap (50 bucks maybe?) so he doesn't have to buy a $400+ BB kit.   

Edited by Wrathchild
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