exhaust popping

[foundryratjim]

I have a 06 RSTD. I installed a set of mufflers from Barons, plugged off the AIS system, balanced the carbs. Barons said i don't have to rejet the carbs. I am still getting some popping on deceleration. Any suggestions?

[oiler]

You have to richen up your idle mixture screws. If you back out each one exactly 1/2 a turn it may solve the problem. I have KhromeWerks on mine and I had to go up one size on each pilot jet plus back out the mixture screws 3/8 a turn. I first tried 1/2 a turn with stock pilots and it got rid of about 75% of the popping. Didn't want to back out the screws any more so thats why a went with bigger pilot jets. Every muffler is different, so I would try backing out the mixture screws 1/4 turn first. If you still get popping try 1/2 a turn. You may get lucky.

[Ace]

A couple of other things to consider are: Loose head pipe causing a leakor mayb an Intake leak.

[oiler]

Ace is right. A loose head pipe or an intake leak can cause popping. But if it wasn't popping before with the stock mufflers, chances are those are not your problems. But just to be sure try your stock mufflers and see.

[foundryratjim]

My mufflers are from krome works also. I wil try adusting the low speed mixture within the next couple of days. I will let you know how it works out.

[foundryratjim]

i cannot find pilot air adjusting screws in diagram in the service manual.

[Freebird]

They are kind of hard to see but if you use a flashlight, you can see them. They are covered with little brass caps. You have to use a long screwdriver to pry the caps off and the screws are under them.

Don

[Stoutman]

I had this issue, and tried the carb re-balance several times. Used some Sea Foam and the problem went away. I think I had some varnish or gunk or a load of stale gas. Anyway, no more popping, and the bike really purs with those carbs synced to perfection.

[foundryratjim]

I have only 2500 mi on mine, i hope the carbs are not varnished up. Does the tank need to be removed to see the mixture screws? I find it odd that the service manual doesn't sho them.

[art]

I had the same problem after installing nasty boy pipes, blocked off AIS noththing, ajusted this that the otherthing, and still nothing.

Now I found something that help not cured the problem but decresed it. The jason mod ! super easy it took me longer to find the right size tubing in the garage than the mold itself do a search on this sight .

hope this helps art

[Royal05Steve]

Also check to see if your Y pipe is leaking. this was a problem with the 05's

[foundryratjim]

I still can't see any brass caps or a place for them. They are kind of hard to see but if you use a flashlight, you can see them. They are covered with little brass caps. You have to use a long screwdriver to pry the caps off and the screws are under them.

Don

[foundryratjim]

Exactly what are you calling the "y" pipe?

Also check to see if your Y pipe is leaking. this was a problem with the 05's

[Black Ice]

Its where the pipe from the rear cylinder joins the pipe from the front. Most of them that had the problem were on the right hand side but I think I heard of some on the left. Mine was on the right. The weld in the pipe under the chrome had a tiny hole in it and it became obvious when the chrome started to blue a bit. Yamaha covered it as a warranty item.

[Buzzard1]

Does the poping hurt anything?----Buzz

[foundryratjim]

I don't believe so. If you were sucking in air at the head which would also cause a backfire you might damage your exhaust valve be the lean burn going on. I also have found that i do have a leak on the right side above the y joint.

[Cougar]

Is there a picture someplace were these caps are?
I need to lean my carbs a little bit

[foundryratjim]

Finally got some nice weather and rode the bike to the dealer. They are going to replace both y pipes. They both have holes where they were welded. During the inspection the mechanic found that my rear shock was leaking oil, so they ordered one also. Now i just have to wait for the parts to come in.

[tazmocycle]

the reason you are getting popback on these bike are because they are retarded timing. you have 2 set of coils, firing 4 cyls, 1&3- 2&4 fires together. one is at compression stroke and firing and the other is at exhaust stroke and firing. thus there is unburnt gas in the exhaust pipes while decellating which lites up causing the poping. you can install the dyna tech 3000 on them and it will take almost all of it out. back in the 70s, holly came out with a ecomomaster carb that shut off all gas to cylinders when you let off the throttle to save gas. i had one on my '75 monte carlo and the fuel ecom went from 15mpg to 19mpg. on the fuel injected bike i think it cut off the gas on decel. only if yamaha would inject the royalls!!!!

[foundryratjim]

This is very intersting information. Is the dyna -3000 programmable? or do they come bike specific?

[Freebird]

Both....they are bike specific but programmable for the rev limiter and timing advance.

[Boomer]

I had the same problem after installing nasty boy pipes, blocked off AIS noththing, ajusted this that the otherthing, and still nothing.

Now I found something that help not cured the problem but decresed it. The jason mod ! super easy it took me longer to find the right size tubing in the garage than the mold itself do a search on this sight .

hope this helps art

ART- I have the exact same set up as you. I did the pilot screw fix over the weekend and NO MORE POPPING. WOOHOO!!:cool10:

[foundryratjim]

Got the bike bake with the new y-pipes. Seems that most of the popping on decel is gone but not all.

[foundryratjim]

My 2006 does not have mixture, at least that i can see. Ihave taken the tank and intake plenum off and cannot see any. If you have an 2006 and can take a picture of where they are at i would appreciate it.I think they have changed the carbs on the newer bikes. Ihave a service manual and it does not show them on the exploded diagram either. Jim



They are kind of hard to see but if you use a flashlight, you can see them. They are covered with little brass caps. You have to use a long screwdriver to pry the caps off and the screws are under them.

Don

[RSTDinPA]

Mine pops pretty significantly with the stock pipes. I do not seem to have leaks in the exhaust. I am going to be changing the mufflers and I am concerned that this is going to make is worse or at least sound worse. Will the Dyna 3000 stop this? I am clueless with carbs. I have plugged the AIS and it has had little to no effect.

[foundryratjim]

Read the threads about adjusting the pilot circuit mixture screws.

[foundryratjim]

I didn't realize what i was looking at.......:confused24: Duh! Adjusted them. Will test ride tomorrow and post if it made a difference.

[foundryratjim]

Backing out the mixture screws did make a difference and elinated almost all of the back firing. I have since installed a Dyna ignition module and all the backfiring has disappeared.

The engine seems to be running smother with the new mudule. I had to lower the idle speed though and it seems to be more cold blooded than before.


I didn't realize what i was looking at.......:confused24: Duh! Adjusted them. Will test ride tomorrow and post if it made a difference.