First Ride 06 YZ450 POP POP POP

What's all that popping about on deceleration?

did it pop less when it warmed up?if it stopped then no big deal.if it didnt stop you are running lean.try adjusting your fuel screw.also check your hot start cable and make sure it isnt holding it open slightly

What's all that popping about on deceleration?

the bike is set up with a lean mixture............

change your jets,,,,,,to

48 pilot jet

170 main

that should help :thumbsup:

I noticed that also every time a decelerated it popped. I'm about 800 ft above sea level in Phoenix.

Mine was doing the same thing, I put a MSR fuel screw in and turned it out about three turns and the popping went away. I will rejet it when the temp rises.

48/170 on the jetting and it will help.

Take it to the dealer. New bikes should not pop.

Take it to the dealer. New bikes should not pop.

shouldn't but they do.

Like Matt said 48/170 takes 30min to change out if that.

shouldn't but they do.

Like Matt said 48/170 takes 30min to change out if that.

yep, what he said :thumbsup:

I'm going to try and buy a 48 pilot jet today and do the change out. I have never had to rejet before so I am nervous. Will I have to mess with the fuel screw or leave it at the stock setting?

I took my new 06 YZ450F out Sunday and experienced the same after break-in. Before going out I installed a MSR pilot screw. Cranked it out 5 full turns. Improved but still popped. I'm going to install the recommended setup found in this thread. Pilot #48 and Main #170. Some of the posts in this thread are saying it takes about 30 minutes.

In the 30 minutes:

Do you have to completely remove the carb? If you do, what's the easiest way?

OR

Can you just rotate the carb? If you can, do you still have to remove the subframe?

So, the new ride is awesome. :thumbsup:

Thanks in Advance.

Here are the steps I followed, be careful when you put the hot-start back on it's plastic and real easy to strip...

take the seat and tank off. remove the hot start from the carb. A little tight, but once the hot start cable and valve are removed the carb can be tilted to let the you see the bottom of the carb and all jets. Much easier to get the bowl off and back on.

Even better. Take off the seat, then tank/shrouds, then the upper motor mounts. Loosen the carb boots and turn the carb like a 2 stroke. Easy access to the bowl.

All I did to get to the bottom of the carb was this - loosen each side of the carb allenhead for each boot - rotate the carb - lay the bike down and remove pilot and main jets - replace & retighten ....took all of 3.5 min.....

I forgot to mention....fuel adj screws make all the difference setting these up correctly.....do yourself a favor go buy one.....otherwise you will be doing this :thumbsup: all the time.....

All I did to get to the bottom of the carb was this - loosen each side of the carb allenhead for each boot - rotate the carb - lay the bike down and remove pilot and main jets - replace & retighten ....took all of 3.5 min.....

Whats he said, it is a piece of cake, 48, 170. No need to get fancy and take the whole dam bike apart, unless you have tons of time on your hands. The screw adjustment will absolutely change! If you have the money, buy the after market screw, much easier to determine how far out you actually are. To adjust the screw, start at say 2.25 turns out, have the bike warmed up, set your idle a little higher than normal. You need to listen to the motor very carefully, don't have your kids near buy to distract you :thumbsup: then adjust the screw a .25 turn out, listen for the idle speed to change, it will every so slightly, when the idle speed stops increasing, your almost at the sweet spot, turn it back a hair. Be patient! turn slowly, wait and then listen, if you need some more info, be gladd to help out!

Even better. Take off the seat, then tank/shrouds, then the upper motor mounts. Loosen the carb boots and turn the carb like a 2 stroke. Easy access to the bowl.

I changed my jets to a 48 pilot and a 170 main today. I ended up doing it like in the quote above. I tried loosening up just the carb boots and rotating, but there just wasn't enough rotation for me to get at the bowl. Popping off the tank, seat and upper motor mounts was a breeze. Removing the upper motor mounts allowed the carb to rotate several degrees farther and I had no problem accessing the bottom of the carb and jets. I love the way that Yamaha did the upper motor mounts. The nuts are pressed into the motor mounts so that you don't have hold them with a wrench while trying to loosen the bolts. Just loosen and remove 5 bolts and the upper motor mounts pop right off. Yamaha even marks the motor mounts right and left so you don't get them mixed up. Now, the carb will rotate without the throttle and hot start cables hitting the upper motor mounts. I did have to cut the zip ties that hold the cables so that the cables had enough slack. Also, I removed the hot start lever (2 allens) from the handle bars to give the hot start cable extra slack. Changed the jets. Rotated the carb back to its normal position. Tightened the boot clamps. Zip-tied the cables. Installed the motor mounts, and torqued the 5 bolts to 40 ft-lbs. Slapped the tank and seat back on. Done.

Now, that I know the routine, the next time will probably take less than 30 minutes.

I'll find out how the bike runs with the new jets this weekend.

Does anyone know if my Zip Ty Fuel Screw mixture adjuster from my '04 YZ450 will work on my '06 YZ450? The carbs are not the same. How about the stainless oil filter? Might as well use what I can.....

Thanks,

Does anyone know if my Zip Ty Fuel Screw mixture adjuster from my '04 YZ450 will work on my '06 YZ450? The carbs are not the same. How about the stainless oil filter? Might as well use what I can.....

Thanks,

I used my Fuel Screw from my YZ250F on my new 06 YZ450F.. no problem! I also did the same with an oil filter, and have not blown up the motor after 5 hours of riding.

All I did to get to the bottom of the carb was this - loosen each side of the carb allenhead for each boot - rotate the carb - lay the bike down and remove pilot and main jets - replace & retighten ....took all of 3.5 min.....

I forgot to mention....fuel adj screws make all the difference setting these up correctly.....do yourself a favor go buy one.....otherwise you will be doing this :bonk: all the time.....

I think this wins as the fastest! I removed the tank and the hot start, and that was easy, but you can bet I will be doing it this way next time. :thumbsup:

Heres to keeping it simple :thumbsup::bonk:

I always replace the phillips head float bowl screws with allen heads.

It makes it much easier to change jets.

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