Athena 290cc Big Bore Cylinder Kit

Question 1

I have a crf150r . Do I have to do any case modification or will it bolt on and work? If not do I need to make any other modifications to the stock engine before installing ?

By Anon.

By **Tom** · Answer

There's no machining required whatsoever to fit these cylinder kits to any machine you select from our fit guide, including all Honda CRF150R models. Just bolt all the included parts in place of the stock items and you're all set.

Question 2

would this bolt up to my 97 yz125?

By Anon.

By **Andy** · Answer

Yes, this kit is offered for that 1997 YZ125. However, you would need to use a pipe from a 1999-2004 YZ125 due to the way the cylinder in this kit is made. It will only work with a pipe from that 1999-2004 YZ125. Other than that, you would just need to machine the cases as shown in the included installation instructions to provide enough clearance for the big bore piston.

Question 3

Stock Yamaha Banshee, can i throw these on a stock banshee without having my case milled?

By Kuntry

Is this bolt on and rip? Can i throw these on a stock banshee without having my case milled?

By **Andy** · Answer

Yes, the kit can be installed on the Banshee engine without any machine work being done.

Question 4

Will it fit to 2007 kawasaki kx65

By Anon.

By **Andy** · Answer

Yes, there is a 80cc kit offered for that 2007 KX65.

Question 5

2000 yz125, does machining need to be done on this model?

By Bold

By **Andy** · Answer

Yes, the kit for that 2000 YZ125 would require you to machine the cases in order to provide enough clearance for the piston.

Question 6

what will i need and will i have to modify the crankcase on a 1999 yz 125

By Anon.

By **Andy** · Answer

You will need to have the cases machined in order to allow the clearance needed for the larger piston.

Question 7

Will I need to mod the case on my 01' yz 125?

By Anon.

By **Andy** · Answer

Yes, you would need machine the cases in order to allow the clearance needed for installation of this kit on the 2001 YZ125. The included installation instructions clearly show how much and where to took out the material.

Question 8

Will this bolt right on 2006 kfx400 or will I need case work

By Anon.

By **Andy** · Answer

Yes, this would be a bolt on kit for that 2006 KFX400. No case machining required.

Question 9

Will this be a direct bolt on for a yz85 or does it require case work?? Also does the crank work with stock bearing or do I need specific crank bearings?

By Kevlar

Also does the crank work with stock bearing or do I need specific crank bearings?

By **Andy** · Answer

Yes, you would need to machine the cases to allow proper clearance. Yes, the crank included would work with the stock style bearings.

Question 10

I own a 2003 kx125 is there any grinding or modification to the crankcase before installation ?

By Chaz

By **Andy** · Answer

Yes, the kit for the 2003 KX125 would include having to open up the cases in order to allow fitment of the new components.

Question 11

Will it fit a 2001 yz125

By Anon.

How much would it cost

By **Andy** · Answer

As long as that is the bike that you choose before adding the kit to your cart, it would be a fit.

Question 12

Will this work for my 1999 YZ 125

By Turbo

By **Andy** · Answer

So long as you choose that 1999 Yamaha YZ125 when adding to your cart and you have a stock stroke length crank installed, you should have no fitment issues.

Question 13

Hi guys I'm just curious to know if this is a straight bolt on kit or am I gonna have to modify anything on my 1997 YZ 125

By Johnny

Hi guys I'm just curious to know if this is a straight bolt on kit or am I gonna have to modify anything on my 1997 YZ 125 and do the power valves include Springs rod and everything else needed for the cylinder

By **Andy** · Answer

According to Athena, to assemble this cylinder kit on models YZ 125 1997-1998, you have to replace the original pipe with a version for the year 1999-2003 and for 1997-1999 models you have to order the 2-torsion original springs (valve) Yamaha year 2000-2003.

Question 14

Can I run this on my 2018 crf 450r

By Dee

By **Andy** · Answer

Yes, there is a kit offered for that 2018 Honda CRF450R. Just be sure you choose that model before adding it to your cart.

Question 15

I've got a 04 yz250 can I use my same power valve or do I need to order a new one

By Anon.

By **Andy** · Answer

The kit for that 2004 YZ250 would actually include a new power valve.

Question 16

would i have to run race gas with the compression ratio being 13.8.1

By zach

By **Andy** · Answer

You should be good with running premium grade fuel, 93 octane or higher.

Question 17

i have a 2019 fc 250 looking to get the 276 kit can i use stock cams or hot rod performance cams

By zach

By **Andy** · Answer

You would be able to use stock cams or aftermarket cams with this kit.

Question 18

I have a 2005 Ltz 400 . Purchasing this big bore but my question is do I have to upgrade my carb or just get bigger jets ? Thank you

By Anon.

By **Andy** · Answer

Yes, it would be recommended to use larger jets with the install of this big bore kit.

Question 19

Will I need to grind the case for clearance of the piston skirt?1998 yz 125

By Clint

1998 yz 125

By **Andy** · Answer

For the 1998 YZ125, it would not be necessary to modify the cases to install this kit.

Question 20

can I get a big bore kit for my 2003 crf230f that would make it a 250?

By James

By **Andy** · Answer

I only see that we offer a 240cc kit for that bike. If you search our site for BBR 240cc Big Bore Kit, you should have no problem finding it.

Specification	Details
Bore	83 mm
Compression Ratio	12.7:1
Country of Origin	Italy
Displacement	290cc

Athena 290cc Big Bore Cylinder Kit

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