SuzukiSavage.com - Tuning out the shotgun

skrapiron -FSO

Serious Thumper

Offline

Instant Human....
Just add coffee..

Posts: 1456
Pittsburgh, Pa
Gender: male

Tuning out the shotgun
03/07/08 at 05:24:49

I have a quick question for you technical types. Is there any adjustment I can do to keep my bike from doing the 'honey, I'm home' howitzer blast? I already did the spacer mod, rejetted the carb, adjusted the A/F ratio (2 1/2 turns out) added a K&N cone and made sure that all of my exhaust connections are tightly sealed. It has eliminated all of the backfiring except on shutdown.

The reason I ask is I rode up to the mall yesterday to return something for the wife. When I pulled in, I noticed a cop standing next to a car taking a report (I guess someone backed into the car then fled). I pulled into a space, took off helmet, then turned off the bike (making sure it idled down after being on the freeway for a while). Well, the standard shutdown BOOM went off, startled the cop who dropped his notepad and put his hand on his pistol while turning to look in my direction.

I'm a bit embarrased by what happened... Is there anything I can do to prevent it?

Back to top

Everything I say is fully substantiated by my own opinion.

IP Logged

tiggerz1 YaBB Newbies Offline SuzukiSavage.com Rocks! Posts: 4	Re: Tuning out the shotgun Reply #1 - 03/07/08 at 05:29:25 I would suggest getting a bullet proof vest just in case lol
Back to top	IP Logged

Reelthing Serious Thumper Alliance Member Offline Fish or ride that is the question Posts: 5397 Houston,Tx Gender:	Re: Tuning out the shotgun Reply #2 - 03/07/08 at 05:40:46 If you really sure the head pipe isn't leaking at all - the pipe to head connection can be a bugger to seal without a new ring as it is a crush gasket- I'd go for the idle mixture - in very small changes like in 1/8 turns
Back to top	IP Logged

T Mack 1 - FSO

Serious Thumper
Alliance Member

Offline

sold 2001 LS650 for
a 1986 XLH1100

Posts: 2919
Emmaus,Pa
Gender: male

Re: Tuning out the shotgun
Reply #3 - 03/07/08 at 06:59:02

Agree with Reelthing. Check the pipe, use a lighter or candle flame to check for leaks. Flame should not get pushed or pulled. In other words, not moved around from gases seeping out, or sucked into the joint from venturi effect (or is it Bernoulli's principle…. ????).

Next adjust low speed screw. Most concern should be given to being centered between the "too lean" or "too rich" points. With a correctly jetted pilot jet, you should be able to get the idle to drop on both sides of the adjustment. Find too lean, then count out to too rich. Do it a couple of times. Then center the adjustment or go slightly rich. Then, adjust in to fully seated while counting turns to see where you're at. If over three turns, rejet. Otherwise you risk the screw falling out since the little spring that keeps tension on the screw so it doesn't move, only goes about that far.

Back to top

Engineers design things, Technicians make them work.
---
30% of being mechanical is confidence/30% is knowing to go slow when needed/30% is looking repeatedly at what you have/10% is dumb luck Wink

IP Logged

Onederer

Ex Member

Re: Tuning out the shotgun
Reply #4 - 03/07/08 at 07:35:17

skrapiron -FSO wrote on 03/07/08 at 05:24:49:

I have a quick question for you technical types. Is there any adjustment I can do to keep my bike from doing the 'honey, I'm home' howitzer blast? I already did the spacer mod, rejetted the carb, adjusted the A/F ratio (2 1/2 turns out) added a K&N cone and made sure that all of my exhaust connections are tightly sealed. It has eliminated all of the backfiring except on shutdown.

The reason I ask is I rode up to the mall yesterday to return something for the wife. When I pulled in, I noticed a cop standing next to a car taking a report (I guess someone backed into the car then fled). I pulled into a space, took off helmet, then turned off the bike (making sure it idled down after being on the freeway for a while). Well, the standard shutdown BOOM went off, startled the cop who dropped his notepad and put his hand on his pistol while turning to look in my direction.

I'm a bit embarrased by what happened... Is there anything I can do to prevent it?

The only thing that would make that funnier, is if instead of a notepad, it was a doughnut.

Back to top

IP Logged

JakeB

Junior Member

Offline

I love YaBB 1G -
SP1!

Posts: 76
NE Ohio
Gender: male

Re: Tuning out the shotgun
Reply #5 - 03/07/08 at 12:29:59

I had the same problem with the stock exhaust, but after I put an aftermarket on, the the bang turned into more of a woof.

One thing I did do on certain occasions to lessen embarrasement was grab the front brake put it in first or second and let the clutch out till it stalled. It's probably not the best thing for your clutch, but it does keep the shotgun from going off.

JakeB

Back to top

IP Logged

Gary On A Savage

Serious Thumper
Alliance Member

Offline

Only 15 mins riding
could save you $$$
in Dr bills

Posts: 941
Fresno, California
Gender: male

Re: Tuning out the shotgun
Reply #6 - 03/07/08 at 14:05:48

JakeB wrote on 03/07/08 at 12:29:59:

I had the same problem with the stock exhaust, but after I put an aftermarket on, the the bang turned into more of a woof.

One thing I did do on certain occasions to lessen embarrasement was grab the front brake put it in first or second and let the clutch out till it stalled. It's probably not the best thing for your clutch, but it does keep the shotgun from going off.

JakeB

I let the clutch out just to where it starts to catch and then hit the shutoff switch (but not stall). Someone posted that a long time back and stops or minimizes it most of the time.

Back to top

'95 Savage with the lowered, full fender look
'96 Honda Shadow 1100 ACE
My Riding Blog: http://garyonasavage.blogspot.com/

IP Logged

Bobbert Serious Thumper Offline CHOP IT Posts: 836 Los Angeles, CA Gender:	Re: Tuning out the shotgun Reply #7 - 03/07/08 at 14:55:17 what is the cause?
Back to top	In progress- 1996 Savage: solo seat, pod filter, open exhaust, and custom bars, fender, wiring, paint. IP Logged

geo Full Member Offline I'm a Savage Posts: 204 Orlando Gender:	Re: Tuning out the shotgun Reply #8 - 03/07/08 at 16:58:48 Switch to the SuperTrapp exhaust. That will end the boom. You will get a ka-pop after gear changes sometimes. Also, you will get noticeably more power.
Back to top	Black 2002 Savage with SuperTrapp 13 discs, Dynajet Kit-DJ144, K&N drop-in, NGK-Iridium, Windscreen, Amsoil 10w-40, Metzeler ME880's IP Logged

rigidchop Serious Thumper Offline don't feed the drama llama Posts: 1105 ravenswood wv Gender:	Re: Tuning out the shotgun Reply #9 - 03/08/08 at 04:57:26 i thought when most people did the white spacer mod, it got rid of the back fire as well. must just need some fine tuning.
Back to top	87 VM ED L IP Logged

Reelthing

Serious Thumper
Alliance Member

Offline

Fish or ride that is
the question

Posts: 5397
Houston,Tx
Gender: male

Re: Tuning out the shotgun
Reply #10 - 03/08/08 at 05:29:40

our shutdown bang is lower speed mixture going lean - either from sucking air at the headpipe, muffler, carb/engine connector, or the mix just needs fine tuned - on the '95 I bet I carried around a little screw driver in my pocket for week working the mixture until it was right on - very slight adjustments 1/16-1/8 turns on the screw - you get it if you stay with it - as long as there are no leaks

Back to top

IP Logged

Bobbert Serious Thumper Offline CHOP IT Posts: 836 Los Angeles, CA Gender:	Re: Tuning out the shotgun Reply #11 - 03/08/08 at 11:49:49 is it just in either direction, or does it need to be richer?
Back to top	In progress- 1996 Savage: solo seat, pod filter, open exhaust, and custom bars, fender, wiring, paint. IP Logged

T Mack 1 - FSO Serious Thumper Alliance Member Offline sold 2001 LS650 for a 1986 XLH1100 Posts: 2919 Emmaus,Pa Gender:	Re: Tuning out the shotgun Reply #12 - 03/08/08 at 12:29:50 Try richer first.
Back to top	Engineers design things, Technicians make them work. --- 30% of being mechanical is confidence/30% is knowing to go slow when needed/30% is looking repeatedly at what you have/10% is dumb luck IP Logged

Reelthing Serious Thumper Alliance Member Offline Fish or ride that is the question Posts: 5397 Houston,Tx Gender:	Re: Tuning out the shotgun Reply #13 - 03/08/08 at 22:42:32 I'd go richer in little bits (mixture screw counter clockwise) - but if your getting on out there at 3 turns out it may time for a size up on the pilot
Back to top	IP Logged

skrapiron -FSO

Serious Thumper

Offline

Instant Human....
Just add coffee..

Posts: 1456
Pittsburgh, Pa
Gender: male

Re: Tuning out the shotgun
Reply #14 - 03/10/08 at 06:00:36

Well, I feel stupid.

the clamp holding the muffler onto the head pipe had slipped and was sucking air in on shut-down (thanks to whoever suggested the candle test to find exhaust leaks).

I replaced the clamp with a heavier auto-parts store model and re-tuned the a/f screw an 1/8th turn. Now all I get is a plesant poof instead of the mortar round.

Thanks again guys!

Back to top

Everything I say is fully substantiated by my own opinion.

IP Logged