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2010 Honda CRF450R

Cylinder Works Big Bore Kit - 478Cc

Retail: $649.99
$589.99
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FITS: 2010 Honda CRF450R change
 
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Product Description

  • Unlock your dirt bike's hidden potential with the power producing and durable Cylinder Works big bore kit.
  • No need to waste your time and money on getting your factory cylinder bored out because the Cylinder Works cylinder is stronger and more reliable. Best part about this cylinder is that it mounts directly to the factory crankcase and head.
  • The piston and rings that come with the Cylinder Works big bore kit are reliable for any motocross race.
  • Even down to the gaskets Cylinder Works employs high quality gasket materials for reliability.
  • Take your 450cc engine and add 3mm for a big bore 478cc with the Cylinder Works kit.
  • The Cylinder Works big bore kit includes: big bore cylinder, big bore piston, piston pin, piston pin rings, gasket kit.
  • Note: to achieve optimum performance re-jet the carburetor with the available jet kits.
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(7)
4.3 out of 5 stars
5 star   5
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3 star   1
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1 star   1
Poe1 Location: Johnstown, PA, USA
1-7 of 7
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Location: Johnstown, PA, USA
Great torque

This kit + stage 2 hot cam + head porting = awsome

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Location: Manistee,Mi
Excellant Kit

I own a motorsports repair shop,customer brought a TRX-450 in that needed a crankshaft and top-end. Thanks to Motosport we were able to rebuild the motor with better parts than stock and save some money at the same time. We have a test track here and before the customer picks up his machine we like to have him or her take a few laps. When they get off their machine and there is a smile from ear to ear you know they are pretty happy.This particular unit the customer was realy impressed. The big bore kit realy woke up the TRX. Thanks Motosport

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Location: north jersey
Perfect fit

works great easy installation everything was there

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Location: whidbey island WA
Problem purchase

Purchased this kit for my 2006 YZ 250F and it took two tries to get a piston and ring combination that fit (rings would not fit in the grooves) finally sent me a piston that worked but it did not have the moly coating. Excellent power gains unfortunately it is on its 4th head gasket due to a poor alingment with the cylinder head allowing the gasket to hang over the combustion chamber. this was possibly the worst purchase I ever made and nobody is willing to stand behind the product, better off buying a Athena kit.

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Top 1000 Contributor
Location: Rigby, Id

I installed this on my 06 yz450f it looks just like the OEM cylinder i did not install the piston instead i ordered a high compression piston. This bike runs like i added another 10 HP. I have been riding it for 3 months with no problems. hill climbing you can't run out of power. power is strong all the way through i would recommend this product.

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Top 250 Contributor
Location: Phoenix, AZ
It's your call

Had some prblms with it.. to start off i have built over 15 yfz motors with no prblms so it wasn't me.. but back to the product. First problem I had was the piston pin clip came out and put a gouge in the cylinder so i went and got another cylinder and rings and clips and maybe had 10 hours on it and I broke a valve which went through my piston and as i tore it all apart again I also noticed that the inside of the cylinder had a crack in it. It could have been from the valve but i dont think so because the valve went through the piston and ive read about the cylinders cracking on other people too. so just thought I'd say if you wanna risk it go for it had lots of power but if you want something that will last i would go OEM. thats where I'm headed now.

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Location: aberdeen, nc
Very nice

Quality construction, made a huge difference in power. probably the most cost effective way to mod a 250f. I did have to rejet with a JD jet kit after i installed this; before it really ran to its potential. Was popping on decel and throttle response was not as crisp. after the bike was rejetted it is a monster.

1-7 of 7
Total Questions (17)
Questions with answers:
  17
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1-10 of 17
Poe1 Over 10 months ago Location: Johnstown, PA, USA
What fuel should I use with this kit?
My bike is a 2002 crf450 I have a cylinder works big bore kit , stage2 hot cam , Tokyo mods carb , hot rods crank and the head has been ported . I hill climb , trail ride and sometimes drag race. I currently use VP110 , is this fuel a good choice? Thanks for your time
MotoSport Staff
Over 10 months ago Location: Portland, OR, USA
For any 4 stroke motor that is not running incredibly high compression you will actually not want to run anything over 100 octane. With fuel over 100 octane it will burn too slow and too cool, and you can actually start to lose power. The VP110 is a great option for fuel, but for your application i would mix it 50/50 with a premium pump fuel. The best option would be if you can utilize a non-ethanol pump fuel if available in your area. With mixing the 110 with a premium fuel, it will give the fuel some consistency that can be lacking in the fuel found at the pump. For all intents and purposes though, this kit would run fine on premium pump gas alone with the correct jetting.
Jymmyee Over 11 months ago
Does this kit need additional tuning for a ltr450, I have a cherrybomb right now ?
MotoSport Staff
Over 11 months ago Location: Portland, OR, USA
This kit will require more tuning capability than what the cherrybomb provides on the LTR450's. If you go with a Power Commander you will be able to get that tuned and running correctly with the big bore kit.
Jimbo Over 11 months ago Location: Anderson, SC, USA
My son has a 2006 Kawasaki kfx400 bored 48 over with custom jet kit for the exhaust and bore kit. Now the battery drains while he is riding.?
My son has a 2006 Kawasaki kfx400 bored 48 over with custom jet kit for the exhaust and bore kit. Now the battery drains while he is riding. Any idea what could be causing his battery to drain and what might fix it?
MotoSport Staff
Over 11 months ago Location: Portland, OR, USA
Electrical issues can be tough, for this I can say that the modifications done to the ATV would not cause this problem. I would start with checking the regulator/rectifier. From there I would check the stator. If you are unsure how to check these items, a service manual would have the instructions or your local dealership can also perform a diagnostic.
kibz32 Over 4 years ago
What kind of carb mods are you looking at doing with the big bore kit??
Expert MotoSport Staff
Over 3 years ago Location: Portland
You will only need to re-jet the carburetor with this kit.
BaoBassgm Over 4 years ago Location: Spain
This kit can be assembled for a YZ400F '99?
this kit can be assembled for a YZ400F '99?
MotoSport Staff Expert
Over 3 years ago Location: Portland
No, only for the bikes listed.
MotorHead420 Over 4 years ago
Will Stock Carb. Work? Will I Need To Jet It ?
Will stock carb. work with the big bore? Will it get enough gas or do I need to jet it more?
Expert MotoSport Staff
Over 4 years ago Location: Tualatin, Or
Yes the stock carb will work just fine. Yes it will have to re-jetted to run properly. Poor jetting can cause damage to the motor. A lean motor make alot of heat
Top 1000 Contributor
Over 3 years ago Location: Rigby, Id
The stock carb will work you should be able to use the same main jet.
Top 1000 Contributor
Over 3 years ago Location: Rigby, Id
the bigger the bore the more air flow which draws more fuel. so there shouldn't be any reason to change the jetting
poman500 Over 4 years ago
Jetting changes ? easy to start? durable?
going on a 2007 honda crf250r
MotoSport Staff Expert
Over 4 years ago Location: Tualatin, Or
Jetting is a reall test and tune subject. A jet setting for a guy in Washington is going to be different from somone in Taxas. So you will just have to play with it and get it right
1 year ago Location: Ca.
Very durable. Have over 30 hours of inter. MX racing on this as well as a stroker crank. Starts like a normal 250f. Tons more torque and HP. Running 45/188 jetting So. Cal high desert. Very happy with the kit. Perfect Vet class bike. 2008 CRF250R.
bigjohn450 Over 4 years ago
What brand of piston is included with this kit? and what compression ratio is it?
Expert MotoSport Staff
Over 4 years ago Location: USA
They package Vertex pistons with their kits.
bdowd Over 4 years ago
Is there any machining required?
i have a 06 crf250
Top 250 Contributor
Over 4 years ago Location: California City, CA
No machining required. Just a simple bolt-on and go set up
Over 4 years ago Location: Hesperia Ca.
On an 08 CRF 250 I know for a fact you will need to grind a little off the case.I believe the 06 and 08 cases are the same. .020" on the front and rear need to be ground off to allow the cylinder to lower into the case.Check the Cylinder Works site.
yfzrider112 Over 4 years ago
With this kit can I use my stock cams or do I need to upgrade them?
Top 25 Contributor
Over 4 years ago Location: Cahttanooga tenn.
stock cams sould work
Top 1000 Contributor
Over 3 years ago Location: Rigby, Id
stock cams work fine but it never hurts to go with a upgraded cam
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