jetting for an '07 450r w/Sparks exhaust

[speedracer350X]

Need info or a place to start from to jet my carb on my 450. It's all stock, just purchased the pipe a month ago. Also wondering what combo air filter/no lid set up anyone recommends. Had an FMF Power Core IV on my 400EX w/ a K@N/ outerwears lid cover, had that dialed in pretty good, so I figure I can handle this on my 450. I see alot of what appears to me are "gimmicks", such as a power now valve, or those bolt on throttle leak jet systems, just wondering are they worthwhile or just to get the jetting down plus the air fuel mixture. Also notice I don't think their is a place to adjust the air/fuel screw. Are those external ones worth looking into? Sorry their's alot of questions. Oh, I'm located here in central PA in the Coal region, probably 1600 or so feet above sea level. Thanks!!

[hondarider101]

i had a 185 in mine w/ a full wb pipe and cam ansd no lid start there.

[d3ktrix]

Originally posted by hondarider101
i had a 185 in mine w/ a full wb pipe and cam ansd no lid start there.


You have an 04 he has an 07, different carb and very different jetting.



Originally posted by speedracer350X
Need info or a place to start from to jet my carb on my 450. It's all stock, just purchased the pipe a month ago. Also wondering what combo air filter/no lid set up anyone recommends.

As a starting point HRC jetting is recommended for an open exhaust and no air box lid.

165MJ
45 pilot
#55 leak jet
Adjust the A/F screw accordingly

And optional is the HRC needle.


Originally posted by speedracer350X
Also notice I don't think their is a place to adjust the air/fuel screw. Are those external ones worth looking into?

On the 07 carbs the A/F screw has a D shaped hole in it ur supposed to use a special tool to adjust.
Its on the front part of the float blow.
Most ppl just stick something random in it to get it to turn.
Or replace it with an aftermarket one.

And yeah all those extra add on float bowel/acclerator pump modifiers are trash.
Changing the leak jet cures the bogging problem people get after removing the air box lid.

[speedracer350X]

Thanks, appreciate all the help.

[d3ktrix]

no problem

[sunco]

I have an 04 -put a curtis pipe on. Way loud. Needed more power to get over the jumps at BPG. The motor blew up at a later date. When it was rebuilt I had the HRC kit put on instead. Much better - not as loud & plenty of power. I bought an 07 while I was getting ripped off at the dealer that did the warranty work on the motor. I went & bought the 07 from a different dealer while waiting for the 04 to get done , I had them put in the HRC for that one also. Power w/o the loud noise;) .
The 07 is faster then the 04. Don't do the pipe.