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jbodin18

04 YZ450 needs more hit!

12 posts in this topic

I'm a newbie to forum but intermediate rider both mx and trails. My bike is super smooth on the throttle, at this point its too smooth. I'm looking to get more pop out of the bike. I rode my buddies 06 KX450 and all the front wheel wanted to do was come off the ground! I loved it! I'm 6'4" 210 and can handle the power. Maybe my bike is exhausted?

So I'm on a budget, and won't be able to go crazy on the bike right away, but over next couple months I wouldn't mind sinking some money into it, if it will increase performance.

Getting ready to get new clutch setup since mine is trashed (5 yrs on OEM clutch not bad). Jetting seems perfect and valves are in tolerance. No aftermarket performance parts on the bike.

My question is: what is list, in order of most significant benefit, you all would consider for upgrading?

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I loved the engine on my 04 that thing hit hard if yours is lacking somewhere it probably is getting tired. I suggest looking into having a leak down test done on it to see where its at. If that comes back fine then maybe someone geared it really high to lessen the hit. I ran 14/47 on my 04 and I loved that gearing combo on that bike. I honestly am less than in love with my new 08's motor and gearing even though I have tried a bunch of different combos on it. Good luck.

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I recently unloaded an '04. The problem with that bike is that it has very quick throttle response and acceleration. It loves to wheelie and spin. Keys to delivering very good response with the motor:

- fresh top end for sure if you are more than a hundred hours.

- proper jetting and fuel screw setting.

- put in a 40 leak jet (check the size)

- check your AP squirt and wire the AP arm or install the o-ring mod.

- Carb probably needs service. If you send it to Zip Ty Racing they will clean it, replace the wear parts, check the AP timing and fix the AP arm for $100. It is a good deal when you consider the gasket behind the slide plate will cost you $25. That gasket can cause poor throttle response too.

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I actually lowered front sprocket 1 tooth (i think to 12 since stock is 13) for more torque at the track and run a 48 (stock) rear. I did o-ring mod couple yrs ago. What do I need to do to check AP squirt and wire?

I'm pretty sure it has well over 100 hrs. What all needs to be replaced when refreshing top end? I imagine I'll find a thread on it.

Thanks guys. Prob time to work the bike over, the new bike I've been dying for keeps getting moved back a yr. Dang kids!

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hmmm my 04 would loft the front in any gear at nearly any RPM. You sure youre doing it right:busted:

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I'm a newbie to forum but intermediate rider both mx and trails. My bike is super smooth on the throttle, at this point its too smooth. I'm looking to get more pop out of the bike. I rode my buddies 06 KX450 and all the front wheel wanted to do was come off the ground! I loved it! I'm 6'4" 210 and can handle the power. Maybe my bike is exhausted?

So I'm on a budget, and won't be able to go crazy on the bike right away, but over next couple months I wouldn't mind sinking some money into it, if it will increase performance.

Getting ready to get new clutch setup since mine is trashed (5 yrs on OEM clutch not bad). Jetting seems perfect and valves are in tolerance. No aftermarket performance parts on the bike.

My question is: what is list, in order of most significant benefit, you all would consider for upgrading?

my first thought is why don't you fix the "trashed clutch" then ride the bike first before you go sinking $$$ bling hop-ups into a tired engine/drivetrain... you are probaby just experiencing a lot of wasted power getting to the dirt stemming from a slipping clutch

My '07 has one of the more mild hitting engines, and I still only use 60% of my engines true capabilities...

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I recently unloaded an '04. The problem with that bike is that it has very quick throttle response and acceleration. It loves to wheelie and spin. Keys to delivering very good response with the motor:

- fresh top end for sure if you are more than a hundred hours.

- proper jetting and fuel screw setting.

- put in a 40 leak jet (check the size)

- check your AP squirt and wire the AP arm or install the o-ring mod.

- Carb probably needs service. If you send it to Zip Ty Racing they will clean it, replace the wear parts, check the AP timing and fix the AP arm for $100. It is a good deal when you consider the gasket behind the slide plate will cost you $25. That gasket can cause poor throttle response too.

Are you sure the o4' YZF has a leak jet??

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Are you sure the o4' YZF has a leak jet??
It didn't. No leak jet on the 450 until '06.

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as said, check that clutch first. i have an 04, run 14/49 gearing and it hits great, anywhere.

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my first thought is why don't you fix the "trashed clutch" then ride the bike first before you go sinking $$$ bling hop-ups into a tired engine/drivetrain... you are probaby just experiencing a lot of wasted power getting to the dirt stemming from a slipping clutch

My '07 has one of the more mild hitting engines, and I still only use 60% of my engines true capabilities...

Ya, I'm sure I'm doing it right, and ya, all new clutch parts ordered yesterday. gonna give the carb a good cleaning again since the gytr clutch kit is backordered a couple weeks.

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