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Cylinder Works Big Bore Kit
Cylinder Works Big Bore Kit

$449.91 - $1063.49
10% Off - Save up to $118.16
Rating: 4.6 out of 5 stars

Select your bike to see if this big bore kit fits

Quantity

Item #CYW0003

8 Reviews

4.6 out of 5 stars
  •   6 reviews
  •   1 reviews
  •   1 reviews
  •   0 reviews
  •   0 reviews

All Reviews

Darius

2 months 17 days ago Wilson, nc
3 out of 5 stars
Still haven't received order yet.

I bought this big bore kit about 2 weeks ago n still haven't received it yet. Can u plz let me kno whats the hold up or do i need to buy another one. I received all my other orders except this one.

2010 kx250f guy

Verified Purchaser
1 year 1 month ago Pa bloomsburg
5 out of 5 stars
Durability
5/5
Ease of Installation
4/5
Performance
5/5
Power
5/5
Style
5/5
Perfect Fit Simple install

Purchased one of these kits after the previous owner hot siezed the piston to the cylinder. Install was cake, nothing different then a standard cylinder and piston, bottom end picked up a little bit for sure, I really recommend adding a few drops of oil to the piston rings and adding a little bit to the top of the piston after it’s in the cylinder to keep it from binding really hard during the install, getting the piston initially in the cylinder is difficult but afterwords it’s a clean install, I run engine Ice with a super cooler kit and I have zero issues with over heating. You will likely require a re-jet kit, a 269 with stage one cams a loudmouth intake and a fmf exhaust caused a very lean run in my bike to the point where starting and idling the bike was almost impossible. I recommend sigma six they’re very helpful. This is on a kx250f 2010

Buddy D

Verified Purchaser
1 year 1 month ago Duncan SC
5 out of 5 stars
Durability
5/5
Ease of Installation
5/5
Performance
5/5
Power
5/5
Style
5/5
Works Big Bore Kit

I just installed this Big Bore Kit with a set of Hot cams stage 2 on my RMZ250. Everything went on perfect with no issues. Starts and runs great only problem is I haven’t got to take it to the track yet.
Thanks you Motorsport for your great customer service.

Shawnzzy

Verified Purchaser
1 year 10 months ago Fargo nd
4 out of 5 stars
Durability
4/5
Ease of Installation
5/5
Performance
4/5
Power
5/5
Style
4/5
Simple to install

Am vary happy with this product simple to install and definitely can tell the increase in torc on the bottom end! Do recommend sending in your computer to be reprogramd for full power gain!

WideOpenMotorsports

Verified Purchaser
1 year 10 months ago Tn
5 out of 5 stars
Durability
5/5
Ease of Installation
5/5
Performance
5/5
Power
5/5
Style
5/5
Good Product

I have never liked the gaskets that come with big bore kits but these actually come with oem style and fit gaskets. Theres no replacement for displacement!

Kevindbike16

Verified Purchaser
2 years 1 month ago
5 out of 5 stars
Durability
5/5
Ease of Installation
5/5
Performance
5/5
Power
5/5
Style
5/5
Bad to the bone

Power difference is great and perfect. Excellent buy

Jake

2 years 11 months ago Riverview, FL, USA
5 out of 5 stars
Durability
5/5
Ease of Installation
5/5
Performance
5/5
Power
5/5
Style
5/5
I will buy again. Greak kit

At first I was skeptical buying this. But after reason all the positive reviews. I decided to buy this kit and a crank kit due to a engine seize I had with oem parts. I put the bike back together and it roared. Sounded meaner. After the break in period,it was hammer down with no issues at all at 15 hours in so far. Bike is running strong and great. I recommend this kit to every one who is looking for a big bore. Installation was a ease with no issue. Also have had zero over heating issues even when running in a Sugar sand feild with the Florida sun bearing down at 89 degrees out

woodsguy

Verified Purchaser
Over 3 years ago
5 out of 5 stars
Durability
5/5
Ease of Installation
5/5
Performance
5/5
Power
5/5
Style
5/5
AWESOME KIT

Improves power where you need it without sacrificing anything. It;s no 450 but it does help narrow the playing field.

35 Questions

  • Answered:   30
  • Not Yet:   4

Question asked by Josh Rivenburg

Question: Will this kit work with a +3mm hot rods stroker crank in my 2005 Honda trx 450r?
Question asked 1 month 6 days ago

Question asked by Mikeyb

Question: I have a 2005 yz450f looking to know if this will bolt up and work without further major modifications 
Question asked 2 months 14 days ago

Question asked by DEEZER

Question: I would be putting this kit on a DRZ400E (2001). Those bikes have a higher compression ratio than the stated ratio of this kit. Do I sacrifice performance because of this? Thanks
Question asked 4 months 13 days ago
Question answered by Paul
User's contributor status: Top 1
Question answered 4 months 13 days ago
Answer: You're right; the original compression ratio on the 2001 Suzuki DRZ400E is 12.2:1.
Cylinder Works and Vertex intentionally selected the lower 11.3:1 compression for smoother firing, and easier tuning.

Question asked by Colbyg99

Question: So I’m gonna order this kit for my 2019 250xcf it says it fits. And adds +3mm of displacement so how many cc is that actually adding and will I have to add a new rod?
Question asked Over 5 months ago
Question answered by robert
User's contributor status: Top 10
Question answered Over 5 months ago
Answer: Its will add CC to the engine but Cylinder works does not list the additional amount added with the +3 of displacement. They will have a mathematical equation to find this but it is not offer to us. It does not require the use of an extended rod.

Question asked by Robbie86

Question: 2004 Suzuki Rmz250, will this work with no case machining?
Question asked Over 11 months ago
Question answered by Chowe
User's contributor status: Top 25
Question answered Over 11 months ago
Answer: According to Cylinder works you would not need to get your case machined. It would be an install and play kit. If you have any questions give us a call at 1-888-676-8853.

Question asked by Roger7457

Question: Hi I was curious what the Hot Rods #4259 was. I wasn't able to find it. I did find a 4059.
Question asked Over 11 months ago
Question answered by Isaac
User's contributor status: Top 10
Question answered Over 11 months ago
Answer: Hot Rods part #4259 is the Heavy Duty (+4mm stroker) makes 424cc with the stock piston. We do offer the item.

Question asked by joseph

Question: I have a 2017 ssr sr250s will this work for that? and what else would i have to buy to compleat the project?
Question asked 1 year ago
Question answered by BillyEXT3407
User's contributor status: Top 25
Question answered 1 year ago
Answer: The Cylinder Works Big Bore Kit will not fit your SR250S.

Question asked by Itshaboy

Question: I have a 08 yz250f would I have to machine the cases for this kit
Question asked 1 year 1 month ago
Question answered by Isaac
User's contributor status: Top 10
Question answered 1 year 1 month ago
Answer: No you do not for your model.

Question asked by Brad3224

Question: Will this 468cc kit bolt right up to my 09 yz450f without any other modifications?
Question asked 1 year 2 months ago
Question answered by robert
User's contributor status: Top 10
Question answered 1 year 2 months ago
Answer: This will be everything needed beside re-jetting or fuel programming on the bike.

Question asked by Mike

Question: I have a 2017 crf250r would I need any other other upgrades to use this? Or would you recommend anything else to go along with this kit?
Question asked 1 year 2 months ago
Question answered by Trevor Gearhead
User's contributor status: Top 10
Question answered 1 year 2 months ago
Answer: To achieve optimum performance, re-jet the carburetor but other than that yo should be good!
1 - 10 of 35

Fitment

See all bikes that this part fits...

# Part Numbers

Product Variant Manufacturer Part #
+2mm 51007-K01
+3mm 11010-K01, 31012-K01, 51006-K01
+3mm/478cc 23001-K01
+5mm 61004-K01
103.5cc 21007-K01
107.8cc 21107-K01
1110cc 61003-K01
159cc 11004-K01, 11004-K02
256cc 12001-K01
269cc 11001-K01, 31001-K01, 31004-K01, 21002-K01, 31006-K01, 31006-K02, 31005-K01, 41003-K01, 41004-K01, 41004-K02, 21010-K01
270cc 11007-K01, 51004-K01, CW11011K01
276cc 51002-K01
365cc 51001-K01, 51003-K01
434cc 41001-K01
468cc 21005-K01, 21005-K02, CW21012K01
469cc 31011-K01
474cc 41002-K01
477cc 11005-K01
478cc 11006-K01, 21003-K01, 11006-K02, 11008-K01, 23001-K02, 21003-K02
479cc 11003-K01
488cc 11002-K01
727cc 11009-K01, 21004-K01, 21004-K02, 21104-K01, 21104-K02
808cc 61002-K01, 61002-K02
859cc 31007-K02
860cc 31007-K01
975cc 61001-K01

California Proposition 65

WARNING: This product contains chemicals known to the State of California to cause cancer, and birth defects or other reproductive harm. Wash hands after handling. For more information, go to www.P65Warnings.ca.gov.