Posts
333
Joined
12/13/2011
Location
Bermuda, BM
Edited Date/Time
6/4/2012 5:02pm
Hey fellas.. just bought a used, beat up and broken 2004 crf 250r for cheap. Im going to make this bike a full blown race bike that is fast as well as reliable. Im starting off with the Athena 280 kit.. Full FMF exhaust.. full Hinson clutch.. Some may wonder why put money into an older bike, well times are tough for alot of people so for $ 3,500 including the price of the bike, i will show that you can have a serious race mahine that is set up just for you..
Some also may wonder that a 280 big bore is more geared for more low to mid range power so how can it be considered a race bike.. valid question and i will show you how to make a big bore scream from the bottem all the way to the top.. I have alot more parts aside from the ones listed above coming next week.. so i will post up pics and info as i go..
First day of the stripdown..
Motor out and ready for inspection..
The bearing Race split in half causing pieces of the race and all 13 bearings to go through the head and down into the motor.. not good.. but being the positive person i am, im going to take a lemon and make a full race motor..
Ready for the new parts.. check back in soon :bandit
Ok ive updated the head to a brand new head from a 2009 model which is a direct bolt on for the 04, the 09 head has a better port configuration for better all round power..
The new head was machined to accept Beryllium Copper Alloy intake seats that are compatible with the new ti valves for a long lasting and reliable set up.. the head is also fully ported for all round power..
Then new Chromium Nitride Coated 1mm oversized Titanium intakevalves were added, along with Black Nitride coated stainless exhaust valves for better exhaust guide wear, springs, spring locators, guide seals, retainers and keepers.
A new cam was installed from the hotcams builder series whick will match perfectly with the 280 big bore.. Instead od the power just hitting hard from the bottem through mid.. this cam will allow the power mostly from mid to top with plenty of overrevv.. the 280 will have plenty on the bottem for an allround power spread.. Also stiffer bigger springs were added to accept the cam..
The FMF Ti powercore exhaust is added along with the powercore head pipe for a light yet powerful setup..
Ive added the tokyo mods cam chain manual tensioner in case the stock automatic tensioner failed which can cause serious engine damage..
This pretty much completes the motor package.. check back in soon for pics and a vid.. ( off to surgery )
Finished Product..
http://www.youtube.com/watch?v=mqsB19hfyGQ
Some also may wonder that a 280 big bore is more geared for more low to mid range power so how can it be considered a race bike.. valid question and i will show you how to make a big bore scream from the bottem all the way to the top.. I have alot more parts aside from the ones listed above coming next week.. so i will post up pics and info as i go..
First day of the stripdown..
Motor out and ready for inspection..
The bearing Race split in half causing pieces of the race and all 13 bearings to go through the head and down into the motor.. not good.. but being the positive person i am, im going to take a lemon and make a full race motor..
Ready for the new parts.. check back in soon :bandit
Ok ive updated the head to a brand new head from a 2009 model which is a direct bolt on for the 04, the 09 head has a better port configuration for better all round power..
The new head was machined to accept Beryllium Copper Alloy intake seats that are compatible with the new ti valves for a long lasting and reliable set up.. the head is also fully ported for all round power..
Then new Chromium Nitride Coated 1mm oversized Titanium intakevalves were added, along with Black Nitride coated stainless exhaust valves for better exhaust guide wear, springs, spring locators, guide seals, retainers and keepers.
A new cam was installed from the hotcams builder series whick will match perfectly with the 280 big bore.. Instead od the power just hitting hard from the bottem through mid.. this cam will allow the power mostly from mid to top with plenty of overrevv.. the 280 will have plenty on the bottem for an allround power spread.. Also stiffer bigger springs were added to accept the cam..
The FMF Ti powercore exhaust is added along with the powercore head pipe for a light yet powerful setup..
Ive added the tokyo mods cam chain manual tensioner in case the stock automatic tensioner failed which can cause serious engine damage..
This pretty much completes the motor package.. check back in soon for pics and a vid.. ( off to surgery )
Finished Product..
http://www.youtube.com/watch?v=mqsB19hfyGQ
The Shop
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$189.95 - $239.95
The Athena product is solid, and piston replacement intervals are the same as stock. One FYI: it's going to feel very "tight" initially (i.e. very hard to kick), almost to the point where you think there's a problem. This is normal, and the engine requires a good 30-60 minutes of use before she loosens up. At that point it may sound like she's about to drop a value, but that's normal as well. Simply loosen & retighten the cylinder bolts to spec, and she should sound like a normal Honda 4T. Which admittedly also sounds like a valve is about to drop..
To clarify I wasn't doubting your skills just sharing the nightmare I went through with the YZ450F. The good news is I developed a great relationship with Anthony Gould and his family along the way which wouldn't have happened otherwise.
Big bores are great. I have only ridden a couple (YZ315F and KTM 350 based on a 250) but have to say the most fun I've ever had a on four stroke was on Den McAdam's Max Power YZ315F. Seemed like it was always in the right gear and I hadn't experienced that in a long time.
In answer to ur question, yes you can use up to a 09 head on the 04
which leads me to believe that the tensioner failed the 1st time, when the bearing failed it pulled the cam, chain, guides, retainers, out of spec.. so going back in the 2nd time, he had no chance and was doomed from the start.. This time a tokyo mods cam tensioner will be going in.. i will definitely update with pics and a vid of it running when done.. Cant wait to see that YZ!!
Pit Row
The thing i dont understand about honda is they claim they stopped producing 2 strokes cause of emissions, using to much oil, then they have their 4 stroke use oil in the head and tranny.. hypocritically incorrect shit son!
I think they changed the design after 04
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