How much backfiring is ok? Any?

[2fs2ns]

Thanks for the info on my other post, now I just have one other thing nagging me.  Is it normal with aftermarket (V&H) pipes for the bike to backfire on decelleration?  It pops pretty good when coming down.  I can get it to backfire at a stop if I rev it a few times pretty good.

Normal?  The previous owner said the carbs where done when the pipes where put on, but I don't know for sure.

The bike will fly when you get on the gas, there's no issues when accellerating, just when decellerating.

Thanks again guys!  Learning a ton about the bike searching through these posts!

[2fs2ns]

Clip of mine doing it at rest, just revving.  I imagine if you sit there revving your bike repeatedly it will backfire eventually.  I recorded the revs.wav file first, and then a second when it finally fired off.

Http://www.thehoffmanns.com/pics/revs.wav
Http://www.thehoffmanns.com/pics/revs_back.wav

[Greg Cothern]

The deceleration popping is due to an incorrect pilot screw adjustment, the little "D" shaped brass adjuster beside the bowl.
With Vance & Hines pipes without a K&N airfilter I have found adjusting the pilot screws to 2 7/8 or 3 full turn out from a light seat is a very good place.  If K&N installed then 3 to 3 1/8th turn is good.
This assumes the previous owner had Dave Dodge jet kit installed.

[Jerry G Turner]

My 94 has vance and hines pipes they backfired a lot until we put in the dave dodge shims and jets, we adjusted them to 3and1/8 turns it doesn't pop at all now during deceleration.

[2fs2ns]

Guess I need to figure out if that dave shims/jets are installed.  Is there a good writeup of doing the job?

[Curtis_Valk]

Also, be aware that the decel pop is not hurting anything, it's just a symptom of a lean condition.  Even a bone stock 3rd Gen Magna will pop on decel, but with stock pipes you really have to listen for it.  Mine pops a bit (bone stock) and I actually kind of like it.

Curtis

P.S.  Nice bike, by the way.  <grin>

[2fs2ns]

Thanks for the info guys, hopefully I'll be able to attend the next wrench session.  From there I'll get shim/jet kit if need be, but hopefully it's just an adjustment.

I'm going to call the previous owner tomorrow and see if he has any more details about what carb work was done when the pipes where put on.

[Greg Cothern]

I have a write up on jet/shims install I will email it to ya.

[Magnum Magna]

I like the popping.  If the person following, should be day dreaming hopefully it will wake them up.  

They say loud pipes don't save live but you don't know how many time someone knows you are there only by the music from your pipes.

[2fs2ns]

Thanks guys.

The popping doesn't bother me so much, however after reading about what the Dave Dodge kit will do, I've noticed that I do have that hesitation around 3k rpms that you guys talk about.

Guess I need to follow those directions to getting the carbs out to see what, if anything was done to them.  If that Dyno jet thing was done, will I need to replace the carbs?  I'll get some pics and let you guys tell me what might have been done.

Thanks!

[Greg Cothern]

If a Dyna Jet kit was installed you can leave it and adjust the pilot adjustments to 2 1/8th turn out.  
The thing I do NOT like about the Dyna Jet kit is they drill the vacuum slides.  With the Dave Dodge jet kit you do not alter anything, this is a big plus in my book.

[SilverFox]

I really like the popping.  It reminds me of a 1954 Ford convertible I had with dual glasspacs.  That car would really talk going down hill if you shifted into a lower gear.  I know there were some people between Tulsa and Tahlequah, Oklahoma who did not appreciate the beauty of the sound when I was returning to school on a Sunday night at mid-night or 1:00 a.m.

[chieninhouston]

My 98 used to pop really loud. After last wrench section, Jesse synchrized my carburatos, also adjusted the screws to 3 turns. Now she really behaves like a lady. Thanks Jesse.
Maybe that's what you need to do: contact Jesse for help.    

[MagnaMan]

You are certainly welcome, James. I'm glad I could help. Incidentally, I just put my stock exhaust back on tonight and man is it quiet. It's very hard to hear any decel popping with those mufflers. But just like Curtis says, it's there, just harder to hear.

[kdf9511]

I did the idle drop pilot screw adjustment this weekend and haven't noticed it poping anymore.