Boggin and Poppin

My 450 bogs slightly off idle and when decelerating, I can hear popping in the exhaust. Any suggestions would be greatly appreciated. I'm on the East Coast at sea level.

Many Thanks! :)

The bog is alittle harder to get rid of without changing the needle but it sounds like your running lean. I am in MA. at the same elevation and I currently have a 48 pilot with stock PAJ(100 I think) 160 MJ and a 65 Sj. It runs pretty good but I am waiting for JD's jetting kit to get it perfect. It should be in the TT store soon :).

Smoke :D

Get the JD kit. I think he is close to the EMN,EMM,EMP needles with some customized tapering that he has developed. :)


It is my understanding that the throttle stop should be cut down or replaced. I have read that removal will affect the throttle position sensor.

You say that you have "lots of carbon", but make no mention of removing the airbox baffle, or rejecting for the muffler insert. Have you cut the gray wire to alter ignition maps? Are you using an aftermarket air filter?

TT members - before we send someone to buy a kit, lets make sure the basics are covered.

I have found acceptable settings close to sea level without popping or a bog while ridding. If I whack open the throttle whist sitting in the garage, it will sometimes stumble or bog. This is not a problem for me because I do not ride in my garage.

Perhaps our jetting expert, LarryCO, could comment - we swapped bikes last weekend. His 426 ran hard.

Ride hard - Take chances


I agree with you CKulzer. Get the basic mods done first. I was never happy with the stock needle. I still recommend getting the JD jetting kit after all the mods. I am ordering my kit today! :)

Indy! What do we do about the pilot circuit. The kit olny addresses the neddle and main circuit? :)

Smoke :D

I think the pilot only needs changing for summer to a 45PJ/70PAJ at our elevation. I will go back to 48/100 in the fall. I got 38, 40, 42, 45, 48 pilots from Yamaha. I think I will need a 40PJ for Colorado in a few weeks. The adjustable air screw does the rest for me. :)


Chad, you're killing me! Yeah, it sure was an experience getting to sit on the new 450...TONS o top end going on there. Very impressed (and scared at the same time!).

Like we discussed before, it's all personal preference...your 450 being a little more tame on the low to mid end with that stocker needle in there...mine being a lot more snappy and running harder down low and in the midrange.

All in all, it's not so much about how well your bike is jetted, it's how you avoid crashing during stream crossings. :)

Thanks again for the maiden voyage in Minnesota...had a great time! Good to be out riding again...

Larry "CO"

P.S. For those that are interested, that 1000K jetting I ran was pretty darn good...perhaps a bit lean on the pilot, but otherwise strong.

Thanks for the input. I just recently removed the airbox snorkel. I'm using the oem air filter and I have not messed with the jetting......

I have had a few folks tell me to switch to a 160/50 set up, but I wanted to throw it out to the experts first.


Where do you order it from? Please pm me and let me know.


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