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2006 Yamaha YZ450F

Athena Big Bore Kit - 478cc

Retail: $853.99
$769.99
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FITS: 2006 Yamaha YZ450F change
 
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Athena Big Bore Kit - 478cc - Main
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Product Description

  • The Athena 478cc Big Bore kit is the missing source for increasing your motorcycles raw power.
  • The included 478cc cylinder on the Athena Big Bore kit is constructed out of aluminum with a galvanic coating to increase the durability.
  • The water jets have been widened for a higher flow rate, keeping the cylinder cool.
  • Athena built a reliable forged piston that has been molybdenum-coated for high performance use and extended wear life.
  • The Athena Big Bore kit includes a specially designed gasket kit to accommodate the big bore features.
  • Another great feature of the Athena Big Bore kit is that it bolts on with no machining needed, and includes easy-to-follow step-by-step installation instructions.
  • The Athena 478cc Big Bore Kit includes: cylinder, piston, ring(s), pin, clips, top end big bore gasket kit.
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Total Questions (10)
Questions with answers:
  10
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Have a question?
“ How reliable is this kit?... ”
zclapper
“ Can I put a stroker crank with this package?... ”
jeffroe
“ Do you recommend using after market cams with this kit?... ”
jmlag0477
1-10 of 10
zclapper Over 3 years ago
How reliable is this kit?
i love the relaibilty of my yfz450 right now i just have to pull the motor anyways cause i have to replace the casehalfs and may as well put a bore kit on it while everythings pulled out anyways
MotoSport Staff Expert
Over 3 years ago Location: USA
As long as the kit is installed correctly you shouldn't loose any reliability.
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dolla Over 3 years ago
If i put a kick starter on my quad do i need to take the butten starter off or can i use both?
Over 3 years ago Location: shamokin pa
no, you can use both.
Answer this Question
dolla Over 3 years ago
Do u need a kickstarter for a big bore kit?
Top 500 Contributor
Over 3 years ago Location: Mckees Rocks, Pa
no you can have an electric start but it may put a lot of stress on the starter or starter gears and eventually wear them out. not a huge concern but its something to consider.
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jeffroe Over 4 years ago
Can I put a stroker crank with this package?
I have got a 2005 yfz 450 I am looking for a package at a good price that will give me more h/p plus be more reliable. I completely blow up my motor and wanted to put more ponies but also make it last but I also wanted to put a stroker crank for added h/p and wanted to know if this would be worth the money spent or if it will just bomb again thinks for your time
Expert MotoSport Staff
Over 3 years ago
On some models you can run the Athena Big Bore Kit with a stroker crank but it usually requires milling the case. The only way to know for sure would be to call Athena 800-222-3375 or HotRods 515-402-8100.
Answer this Question
ATVDUDE Over 4 years ago Location: Wilcox, NE
What would the cooling reasons be when you have a cooling system already?
MotoSport Staff Expert
Over 4 years ago
Because you are changing the displacement, and with the current water jackets in a stock cylinder it would create more heat, which means more wear. So with larger water jackets in this kit, the cylinder will stay cooler to save on wear and numerous potential problems that can relate to over-heating.
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jmlag0477 Over 4 years ago
Do you recommend using after market cams with this kit?
MotoSport Staff
Over 4 years ago Location: Portland, OR
Normally yes, for peak performance you should at least run a stage 2 cam if someone offers it for your bike.
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AJ541 Over 4 years ago
What is the gain in HP and torque with this kit?
I have a stock 2003 YZ450F and wanted to know what kind of gains in HP and torque would come by adding this kit to my bike. Also what other mods would you recommend if i were to install this kit; pipe, cams, etc?
MotoSport Staff
Over 4 years ago Location: Portland, OR
It's really hard for me to give you exact numbers on what the HP and torque gains will be on a stock motor since Athena doesn't give us that information. If you want more specs you can always email info@athenausa.com. As far as other mods, personally I would knock out the small things like the Boyesen quick shot, an air filter, an exhaust, maybe the power now system dial in your jetting then I would look into a big bore kit. All in all it's up to you but that my opinion.
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webster Over 4 years ago Location: phx.
What is the compression ratio of this piston?
example, 12.5:1 or 13.25:1
MotoSport Staff Expert
Over 4 years ago
depends on the application
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Mxerdude Over 4 years ago Location: Charleston, SC
Does the kit bolt right up to my head and valves? Is There any other modifications that are required; jetting, boring? And lastly how reliable is it?
I am a upper level B rider and i am considering this for my 2008 yamaha yz450f.
Expert MotoSport Staff
Over 4 years ago
this does fit your bike. it just bolts on. but you will want to rejet. you get a new cylinder with the kit so there is no boring.
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yfzracer106 Over 5 years ago
With this big bore kit can you run regular pump gas?
MotoSport Staff Expert
Over 5 years ago
Sure you can run pump fuel, but I wouldn't recommend it. I recommend running a high oxygenated fuel for cooling reasons.
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