50% of Power Up for 2004 CRF150F

I want to do half of the 'Power Up' mod. I will remove the intake snorkel & rejet.

42 slow jet

112 main jet

I do not want to remove the exhaust baffle (concerned about noise). Do I need to replace air filter w/ uni-flow or twin-air, or does stock flow enough w/ snorkel removal? Is there any other mod required to the airbox?

Also, how do I know if I picked the right size jets? Can someone point me to a link on how to dial in these carbs?

Thanks!

You might want to try removing the baffle just to hear the difference. It really isn't that much louder than having it installed. As far as which main jet to use if you search the forum you will find a lot of info on how to determine what main jet you'll need. Also don't forget to move the clip on the needle down 1 position, towards the pointed end. The stock air filter is very restrictive so it really needs to be replaced to get the maximum gain in performance.

You might want to try removing the baffle just to hear the difference. It really isn't that much louder than having it installed...
Is it possible to reinstall the baffle, or is the removal permanent?

It's held in with the small screw on the outer edge near the end of the exhaust. I have the same year bike and there is a noticeable power increase if you do all the power up mods and it isn't much louder than stock. Check out Powroll's thrust chamber also. It attaches to the end of your exhaust, does not make it louder and adds a bit more power.

It's held in with the small screw on the outer edge near the end of the exhaust. I have the same year bike and there is a noticeable power increase if you do all the power up mods and it isn't much louder than stock. Check out Powroll's thrust chamber also. It attaches to the end of your exhaust, does not make it louder and adds a bit more power.
So, if I remove the three screws on the back, I'll get to the inside of the muffler, and then there will be one more screw that holds the baffle in place?

No there is one screw on the underside of the exhaust on the right side. Removing the baffle will make the bike almost as loud as an aftermarket system. It will have a deep tone like a 450.

Edited by crf150f guy

I'd maybe go smaller on the main jet

at 800foot mine is rich with a 110 main with the baffle in the exhaust, WAY to rich, my bike runs like crap when I put the baffle in with a 110 :banghead:

I'd maybe go smaller on the main jet

at 800foot mine is rich with a 110 main with the baffle in the exhaust, WAY to rich, my bike runs like crap when I put the baffle in with a 110 :banghead:

Most people say a 112 w/ the intake & baffle. Wonder why it is rich on your bike?
Most people say a 112 w/ the intake & baffle. Wonder why it is rich on your bike?

There are a lot of variables that can change what main jet works best for a bike. It isn't uncommon for 2 identical bikes ridden in the same general area to require different jetting.

I actually use a 110 main also. I've tried a 115, 112, 110 and 108...the 110 worked best for me.

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