Includes aluminum cylinder with nickel-carbide coating on 2-stroke machines and galvanic coating on 4-stroke machines
Specially designed, high performance, forged piston kit
Included top end gasket set comes with all required seals and hardware
Easy to follow, step by step installation instructions
Made in Italy
Product Note:
Specification
Details
Bore
Varies (make selection above)
Compression Ratio
Varies (make selection above)
Country of Origin
Italy
Displacement
Varies (make selection above)
Material
Varies (make selection above)
Size Over Standard
Varies (make selection above)
Vehicle Fitment
Fitment is guaranteed or your money back plus free return shipping.
Don’t waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.
Awesome kit. Son has put 100 hours on this kit so far with no issues.
Big bore
By Mike Z. on
Verified Purchaser
I had no problem with this kit...big bore kit works good....got mine all broke in and it runs really good...glad I got it...
Runs great
By Ripper on
Verified Purchaser
Bolts right on. No grinding on crankcase necessary for 1999 yz125. Runs great
Everything’s good but the power valves
By Thomasj on
Verified Purchaser
Everything was good until I tried putting the power valves in. The valves didn’t fit correctly so I had to file them down to make them seat all the way in correctly. Other than that it all seems good.
Double thumbs up
By Ethan S. on
Verified Purchaser
Bought the big bore kit for a 2006 klx110, very high quality kit comes with everything you need. The kit is the best bang for your buck. Really wakes the bike up.
Very good
By Jason A. on
Verified Purchaser
Made my ltz400 a missile.
How many stars would you give this product? Write a review.
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.
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.
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?
Yes, you would need to machine the cases to allow proper clearance. Yes, the crank included would work with the stock style bearings.
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.
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
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.
Verified Purchaser
