[Gavinfitz03]

I know this topic has been brought up a lot but there’s never a solid answer, so I have a 2006 trx450er with the HRC and a white brothers carbon exhaust and currently I’m running no air box lid, 178 main, 45 pilot, 75 idle, 55 leak jet, 2 1/2 turns out on A/F and I’m about 1000ft in elevation. I am having deceleration popping and it’s only at the bottom of the gear I tryed adjusting my A/F and at four turns out it only piped once or twice. I know anywhere from 3 out or more based of what I’ve read is that I need to go up on the pilot so I put a 48 pilot and the popping basically went away but when I turn the quad on there is a loud pop every time and it cranks a little more before it starts. It started up almost instantly with the 45 pilot. What is the cause I’m very confused?

 

[jaydnrob]

I know this topic has been brought up a lot but there’s never a solid answer, so I have a 2006 trx450er with the HRC and a white brothers carbon exhaust and currently I’m running no air box lid, 178 main, 45 pilot, 75 idle, 55 leak jet, 2 1/2 turns out on A/F and I’m about 1000ft in elevation. I am having deceleration popping and it’s only at the bottom of the gear I tryed adjusting my A/F and at four turns out it only piped once or twice. I know anywhere from 3 out or more based of what I’ve read is that I need to go up on the pilot so I put a 48 pilot and the popping basically went away but when I turn the quad on there is a loud pop every time and it cranks a little more before it starts. It started up almost instantly with the 45 pilot. What is the cause I’m very confused?

That’s a good question my buddies 07 does it every time he starts and and mine 06 does it here and there.

 

[Bullvine rider!!]

My quad did the same before its current rebuild. I was told it was normal. But after the build it stopped. The shop put a 130 main, 50 slow jet (im assuming thats the pilot jet) and 75 starter jet. They didnt write down the leak jet. Not sure why. 2 1/4 out on pilot screw. But my quad seems to run the best on the lean side With no decel popping on a 130 main i know crazy 🤷🏻‍♂️. My elevation is less than 1,000.
try going down on your main? I know it seems assbackwards but you never know. Maybe a 162 main with the 45 or 48 pilot to see what works best.Im know carb tuner but again i was told mild popping on decel is normal. Popping on accel is an issue tho.

 

[Gavinfitz03]

My quad did the same before its current rebuild. I was told it was normal. But after the build it stopped. The shop put a 130 main, 50 slow jet (im assuming thats the pilot jet) and 75 starter jet. They didnt write down the leak jet. Not sure why. 2 1/4 out on pilot screw. But my quad seems to run the best on the lean side With no decel popping on a 130 main i know crazy 🤷🏻‍♂️. My elevation is less than 1,000.
try going down on your main? I know it seems assbackwards but you never know. Maybe a 162 main with the 45 or 48 pilot to see what works best.Im know carb tuner but again i was told mild popping on decel is normal. Popping on accel is an issue tho.

The HRC came with

My quad did the same before its current rebuild. I was told it was normal. But after the build it stopped. The shop put a 130 main, 50 slow jet (im assuming thats the pilot jet) and 75 starter jet. They didnt write down the leak jet. Not sure why. 2 1/4 out on pilot screw. But my quad seems to run the best on the lean side With no decel popping on a 130 main i know crazy 🤷🏻‍♂️. My elevation is less than 1,000.
try going down on your main? I know it seems assbackwards but you never know. Maybe a 162 main with the 45 or 48 pilot to see what works best.Im know carb tuner but again i was told mild popping on decel is normal. Popping on accel is an issue tho.

whats done to yours? Do you have an HRC? The HRC comes with a 165 main and I was running lean on top and the 178 I have in now seems to be the best I’ve tried

 

[Bullvine rider!!]

I have the hrc cam (early one i bought of someone) new cam chain ,new 12:5-1 piston, rings, crank shaft bearings. Pretty much a full rebuild. With sparks full exhaust, uni filter, semi open lid (aluminum air box). I just drilled out my breather T so its like the hrc mod. i put the small filter on my breather hose’s.
im still a little skeptical about the 130 main. Im going to buy some keihein jets and go up on the main tho.
from what ive read 130 is very lean. But the quad is running good. During break in it would stall when hot and pull in clutch. Then have a hard time starting afterwards untill it cooled down.
i thought decompression or valves were off, but all that was just checked/adjusted during the build. So i turned my idle up a bit and turned my pilot screw in a 1/4 and problem solved.
But im pretty sure with the hrc and or full exhaust mod the jets go from stock (main 122) to 162, stock pilot stays and 55 leak jet. Pay no attention to 75 starter. Thats atleast what ive red from mr. Greg 450RR in old posts. Type in jetting questions in the community search and look for his post. Its very long but super informative. I just read it and thats why im going to go up with my main and try to find that perfect tune. My quad runs good but could be better.
Plus everyone and their mother told me 130 is too lean and to try the 162 main

 

[Bullvine rider!!]

But if you’re quad is running good and its just mild popping on decel. I wouldn’t worry about it. Ill be back on here bugging everyone when i start messing around with changing jets abd tunning. I still can wrap my head around my main being 130 and running good 🤷🏻‍♂️, it goes against everything i read about jetting. Too lean doesn’t play nice with engine components.

 

[Bullvine rider!!]

Sorry i was wrong sbout 162. You’re correct its 165. But if you say it was lean up top and what you have now works best then…….. i guess we all want our quads to run perfect. These 2gens are temperamental. I still have alot to learn with jetting, theres no exact science to it. All quads are not created equal lol. But like i said 450RR’s post is damn near close to exact science and he covers just about every angle.
You should check it out. Jetting questions in the search bar and you will find it. Good luck!!