ive been hearin that if u take out this baffle u gain some horse power right so i got lookin and how in the hell do u take this baffle out and if u take it out are u able to put it back in if ya have to id love to take it out and leave it out but i ride at silver lake and thats all i need is to get caught with out the baffle in there and that would ruin that so could ya tell me how to get this thing out and does it go back in with no problems thanks.

 

My uncle told me to do it to my Raptor 660R but he said if you do that you should jet it first. I don't know if its the same for all sport quads.

 

It should tell you how in the manual, but if it doesn't the muffler should have some bolts that hold it in.

If you take out the baffle, take off the airbox lid, and jet up a little bit, I have been told it will make a whole new bike.

Good Luck

 

One small bolt on the back of the muffler is all you have to pull to get it out. If it was like my Raptor, it took a little bit of pulling to get it out. I would imagine that it will come right out considering the age of the bike.

If you don't mess with the airbox, the change as far as the exhaust flow will probably not do a whole lot as far as the fuel mixture goes. I don't have any first hand experience with the YFZ.

Good luck!!

 

Jetting after you pull the baffle and take off the air lid what jet size do you jump up to?

 

The airbox lid off and removing the baffle will give you five more horsepower.

the silver back on the pipe has three screws, remove them
then there is a screwunder the baffle in the middle of the pipe, remove it also.

then start the bike and let it idle or have some one rev it a little. grab the baffle and rotate it counterclockwise and it should fall out, then shut off the bike.

remove the large screw under the carb and put in a 165 kehein long jet series 13, exactly the same as the motorcycles jets. do NOT tell the bike shop you have the 450 they ALWAYS GIVE YOU MIKUNI JETS!

they ALWAYS THINK YOU HAVE A BANSHEE
so tell them I do not want mikuni jets I want kehein jets
you should now have 45 horsepower dude.


if you want 50 horsepower you have to do the exhaust cam modification. that is a little more involved but you can take it to your shop and tell them DUDE, rotate my exhaust cam ONE TOOTH CLOCKWISE PLEASE and they should be able to do it.

They will think you are crazy, cause every other bike in the world will NOT RUN after you rotate the exhaust cam one tooth clockwise, but this one will run like an ape with his tail on fire after you do it.

you also have to jet to 170 if you do this mod and change the needle to clip 6

to change the needle to clip 6, you have to grind off 1/8 inch off the blunt end of the needle.


after these two modifications we raced a pure stock YFZ450 agaisnt the modified one, and the modified one, in a 300 foot drag was ahead of the stock one by EIGHTY FEET!

that is EIGHT OH FEET.
you have 50 horsepower now.

have fun.

 

thats sounds like you have done this before there buddy see i ride at silver lake with my buddy and his dad usally but now im going to have 2 raptors with me and im always in search for the power so thanks for the help.

 

If yor putting the clip in the 6th position that leads me to beleive that the pilot jet is to small.. Dont you think?[img]i/expressions/face-icon-small-happy.gif[/img]

 

I'm curious about a few things and maybe you could clarify them for me.

1- My YFZ manual says to remove the inset bolt on the back of the pipe to remove the spark arrestor. Is this what your indicating to remove? If so, why are you removing all the other bolts?

2- What does the YFZ come stock with for jetting and clip setting?

3- Any clue as to where I can obtain Yamaha's speifications for jetting on a stock engine (no mods to pipe or filter box) that will be operated in 8000 to 12,500 feet?

Thanks

 

daddogrider you still out there???????