Total Motorcycle Community Forums

I recently purchased a new Venture. I just put Bubs slip on Mufflers so I could be heard while riding in traffic. Here lies the problem. Now the bike pops and backfires as soon as I let of the throttle. I have been told by one Yamaha Dealer here in Vegas that I should have a ball bearing inserted into an airline for the emmisions and that would stop the poping. at a cost of 175.00. Another shop recommends rejetting and new performance air cleaners at a cost of around 400.00 however dynajet does not make a jet kit for the 05 royal star. Im lost as to what to do. I want the best possible fix to the problem.

Thanks in advance

Bill in Vegas

You really only need to post these things in one place.

http://www.nopork.com/shop_product.asp? ... erformance

They and many others make a jet kit for your bike. Royal Star Ventures are mechanically the same 99-06. That being said a jet kit might void your 5 year warantee if your dealer is a jerk.

Its probably not the after market pipes causing the backfire you hear. Its more than likely the air leaks caused when the gaskets weren't replaced and/or any other leaks not being sealed when they were installed. Fresh air is drawn in through those tiny holes and provides sufficient oxygen to ignite any unburnt gases inside the muffler. Try replacing any gaskets and tightening all exhaust bolts and clamps....

I don't think this will hurt your bike any. And you will be heard with the popping going on like that. My 454 LTD did that, I kind of liked it.

I think that re-jetting is the way to go for your bike. Anyone I heard of that has changed the exhaust of their Yamaha needed to re-jet.

Hey Graniteguy, I am just about to purchase an 05 RSTD wich has the same drive train as your bike. I was wondering if I was going to have to replace the stock pipes. I do not like a loud bike but I do want it to sound strong. Does the stock pipes sound that weak??

Dave

graniteguy wrote:I have been told by one Yamaha Dealer here in Vegas that I should have a ball bearing inserted into an airline for the emmisions and that would stop the poping. at a cost of 175.00.

http://www.gadgetjq.com/smogstuffremove.htm

It's for a Vulcan, not your bike, but it explains the marbling technique. There's no need to rejet just for slip-ons.

The dealer is correct that plugging the emissions will stop the backfire but is trying to really RIP people at $175.00. You can easily plug it yourself and the cost will be about $3.00.

http://www.venturerider.org/forum/showthread.php?t=231

Don Nelson
VentureRider.org

The Ventures are bad about getting raw fuel in the AIS valve. There are two of them on this model, one for the front bank of cylinders and one for the rear. The rear is the one that gets raw fuel in them, primarily from out-of-synch carbs.
The valve is located on the bottom right hand side of the bike. I guess look under the bike around the back tire and follow your way forward. You should see a cylinder shaped object with two fat hoses and one small vacuum hose on top. The Valve is held on with a spring clamp which is held down with a #3 phillips screw. Take this valve off, noting where the hoses are, and see if there is any raw fuel in it. Just shake it around, it should come out of the small vacuum hose inlet.
Or block off the AIS system altogether which has been mentioned.
Or you can drill out the brass plugs on your carbs that will gain you access to your mixture screw. All factory bikes are set up lean, and the slip-ons only contribute to this. Have someone who is knowledgeable show you where these plugs are. Once removed, turn the flat head screws in all the way, lightly. Then back them out about 3 turns. This should richen it up enough to get rid of the backfiring problem.
But check that AIS valve anyway...it is a very common issue with the Venture. Good Luck.