Wiseco 2-Stroke Piston

$87.99 - $201.99
$45.77 - $171.99
4.50 5 4
4.50 out of 5 stars
Fitment Expert:
Dirt Bike Dirt Bike ATV Make Year Model
Wiseco 2-Stroke Piston
Wiseco 2-Stroke Piston
  • Description
  • Reviews (4)
  • Q&A (17)
  • Fitment

Wiseco leads the performance aftermarket by producing the highest quality forged pistons in the U.S.A. Wiseco is unique because they forge all of their own pistons in-house, and produce all of their own forge tooling in the U.S.A. This allows Wiseco to control all aspects of their manufacturing process from raw bar to skirt coating on the finished parts.

Extreme racing conditions demand the strength and toughness that only forged pistons can offer. Compared to cast pistons, forgings are tougher and more durable, and will stand up to the abuse that high performance motorsport applications require. Most castings are brittle, have no grain structure and tend to fail catastrophically when the material yield strength is exceeded. Forgings have condensed grain that is aligned to the features of the part, which produces higher mechanical properties, and resistance to impact and fatigue. Each forging is designed to optimize the strength-to-weight ratio, and maximize performance.

  • Much stronger than stock.
  • Tight tolerances for quiet running.
  • More hours with peak performance between piston changes.
  • All pistons include rings, wrist pin and circlips.

Note: Image is for reference ONLY, actual contents will vary based on fitment.

4.5 out of 5 stars (4)
4.5 out of 5 stars
5 star   3
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3 star   1
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1-4 of 4
Overall 5 out of 5 stars
Ease of Installation
Verified Purchaser
Location: Ephrata, PA, USA
It's a Wiseco, Nuff said.

Saw the Wiseco reps at the Hi Point National. Could'nt thank them enough for helping to keep my 1978 RM125 running strong.

Overall 5 out of 5 stars
Ease of Installation
Location: Illinois, USA
PW50 Top End

Replaced Top end on a PW50. Cylinder, Cylinder head, pistion, rings, circlips, gaskets, & new nuts.All parts came in within 5 days. Everything matched up perfectly. I have done plenty of business with Motosport over the years. They have good prices & parts & service are excellent!

Overall 5 out of 5 stars
Ease of Installation
Top 25 Contributor Top 50 Contributor Top 10 Contributor
Location: I Live in Adams TN Race 25 times a year Vet AM
Wiseco top end set

Wiseco pistons are lighter, produce more power, last longer, and are cheaper than OEM. Using the Wiseco kits is a great way to go all the parts in one box! Take your time setting the ring gap thats as technical as it is!!! On a new bike as soon as it needs rings I swap the whole top end set, keeps it fresh with new with reliable parts.

Overall 3 out of 5 stars
Location: oakland, ca

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Total Questions (17)
Questions with answers:
Questions without answers:
Prezz8 Location: Grove City, PA 16127, USA
1-10 of 17
Kickstand 1 month 9 days ago Location: Toano, VA, USA
I have an 85 rm80 with a stock bore of 47.5mm. It has an oversize of 0.020" already. Im looking for a 0.040" piston set. 1mm over?
I want a piston kit for my application but can't find it browsing your website
Yann Over 10 months ago Location: Quebec City, QC, Canada
What is the compression height on a Suzuki Rm80 1983-1985 piston?
Can't find this information and I need to know if it is the same as the newer Rm80 which is 27mm.Thanks
Expert MotoSport Staff
Over 10 months ago
Wiseco does not provide that information. I would try contacting them directly at Toll Free: 1-800-321-1364 or 1-888-494-7326 (Canada)
Gbarbee Over 12 months ago
My bike is bored over all the way. And I took the cylinder to the local parts store and they said I needed a 52mm piston. So would this piston fit?
Top 1 Contributor
Over 12 months ago
Yes! The largest piston that Wiseco makes for your 2006 Honda CR85 is a 52.00mm sizing. Be sure to select the correct size in the pulldown menu. Also, feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.
Prezz8 1 year ago Location: Grove City, PA 16127, USA
What is correct piston/ring size for a bore measuring 54.25mm?
1985 Honda CR125
Top 1 Contributor
1 year ago
Wiseco offers the following bore sizes for the 1985 CR125:


Consult your service manual to determine the correct size piston with the clearances required. If you need more help, consult a local service or machine shop to help you.
rdubtx 1 year ago
PW50 overbore question?
I have a 2004 Yam PW50 with original cyclinder which has scoring. Shop says should be able to overbore back into round. Mic'd it at 39.80-39.50. Which oversize piston should I order before having bored so I can take to the machinist to ensure he bores for correct clearance?
Top 1 Contributor
1 year ago
Wiseco list the following sizes of pistons for the PW50s:

40.00 mm
40.25 mm
40.50 mm
40.75 mm
41.00 mm
41.50 mm
42.00 mm

You will need to consult the machine shop to tell you which size of piston will fix the issues with your cylinder.
Rj1Nash 1 year 1 month ago Location: New Port Richey, FL, USA
Im in need of a STD piston with rings?
i have a 1995 yamaha rt180. i have a .050 piston with no rings.i need the standard piston head with rings.
Top 1 Contributor
1 year 1 month ago
Wiseco does NOT make a piston for the RT180. I would suggest to check if the OEM Yamaha parts are still available for your bike. Also, feel free to give us a call at 888-676-8853 and we would be happy to help you out with your order.
Heff 1 year 4 months ago
Does this kit come with a needle bearing?
1979 rm125
Top 1 Contributor Top 50 Contributor
1 year 3 months ago
The Wiseco 2 Stroke Piston kit does not come with a wrist pin bearing. You can order that separately or or the top end kit which includes the piston kit, top end gasket kit and wrist pin bearing. We may not have fitment for you 1979 RM125 model bike.
Dugnut 1 year 8 months ago
I'm needing to replace piston on a 84 rm 125 and the bore on the cylinder I measured at 55.016mm what do I need for piston and rings?
MotoSport Staff Expert
1 year 8 months ago
55MM is a 1.0 over stock bore size (specific to your model). Judging by your measurement you'll want to contact us to check availability for your year and model bike. Feel free to give us a call so we can help you out!
Justinsanger 1 year 9 months ago Location: Wichita, KS, USA
Do I need to have the cylinder machined.?
I have a 97 rt180 with low compression. I have never done a rebuild and wasn't sure if I needed to have the cylinder bored or how to tell. Also what is the stock bore. Any answers help. Thank you
Expert MotoSport Staff
1 year 9 months ago Location: Portland, OR, USA
It is hard to say without seeing the inside of the cylinder whether or not it will need to be bored out. It is possible that just replacing the piston/rings would fix the lack of compression but I would recommend taking the bike to a motorcycle shop with a service department to have it looked at.
jeff 2 years 2 months ago Location: ga
Need to order rings 2003 rm 124 w/ 58mm bore?
MotoSport Staff
2 years 2 months ago Location: Portland, OR, USA
If you give us a call we can provide pricing and availability of the 58mm rings for your 2003 RM125.
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