SuzukiSavage.com - carb adjustments....and backfire

Jsud04

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carb adjustments....and backfire
05/08/14 at 16:04:47

I got my carb tune to the point where it idles well and the is no shut off pop...however when I decelerate and engine break hard it will gurgle pip and pop and on occasion it will backfire. Not while shifting though...

I was always under the impression backfires were caused by running rich not lean...?

Also, if I put a video on utube could y'all tell me if my odle seems right?

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1986 red, raptor petcock, cham chain tensioner mod,carb plug pulled. DIY highway pegs, DIY ammo can storage...

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OdysseusNY

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Re: carb adjustments....and backfire
Reply #1 - 05/08/14 at 16:25:17

In case you haven't seen it:

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1221818822/0#0

The idle screw adjustment improved my backfire situation. However, i can still make it happen if i come off the throttle very quickly at speed. I just don't sweat it and treat the occasional backfire as my bike scolding me for not having smooth throttle control Grin

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Serowbot

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Re: carb adjustments....and backfire
Reply #2 - 05/08/14 at 16:25:48

Funny, because most people are only aware that bikes pop if they are lean...
Both.. you can have rich-pops or lean-pops...
This is why most carbed bikes pop in the mountains.... they get rich from the thinner air...
Jet for the mountains, and you'll pop down in the city...

Gurgles and pops are normal for this bike... you'll grow to love them...
We just try to avoid the hard gunshot backfires (afterfires)...

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Rembrandt Full Member Offline SuzukiSavage.com Rocks! Posts: 107 Peterborough, Ontario, Canada Gender:	Re: carb adjustments....and backfire Reply #3 - 05/08/14 at 19:11:31 Should I be concerned then? My bike sounds at least as loud as a firecracker, if not a gun upon pretty much every shut down. Does this damage something? I've come to enjoy watching people jump out of their boots at gas stations.
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Steve H Serious Thumper Offline SuzukiSavage.com Rocks! Posts: 1223 Spartanburg, SC Gender:	Re: carb adjustments....and backfire Reply #4 - 05/08/14 at 20:55:58 I get a nice loud boom on shutdown. If it's dark, about a foot long blue flame from the boom. A normal little bit of burbling on decel. I'm like Rembrandt, I like the feedback and seeing everybody jump is just a plus. The boom does usually get amplified really well by the roof and building sides at gas stations.
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Rembrandt

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Re: carb adjustments....and backfire
Reply #5 - 05/08/14 at 20:58:55

I should add that I farted around with the mixture screw and the idle speed knob last spring when I bought the bike. The idle speed is at least fast enough, probably faster than needed, to keep oil moving where it's needed. Through playing with richness screw, I eliminated the decel backfiring, but was still left with loud shutdown bang. I had enough of messing with what I couldn't seem to remedy. Spacer mod done last year too because it balked and hesitated horribly upon purchase in lower gears travelling through town....this problem completely fixed...and, not really related, but Versy also done...very pleased and grateful.

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Rembrandt Full Member Offline SuzukiSavage.com Rocks! Posts: 107 Peterborough, Ontario, Canada Gender:	Re: carb adjustments....and backfire Reply #6 - 05/08/14 at 21:00:29 Too funny Steve H. I too note and appreciate the extra echoing effects of shut-down kabooms at service stations.
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Serowbot

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Re: carb adjustments....and backfire
Reply #7 - 05/08/14 at 22:09:27

Well,... mine used to kerpoww on shutdown... but, I've changed jetting, muffler , idle, and air filter...
Now, it just goes whoomph...

...but,... regardless... jet your bike to run well...
If it runs well,.. don't worry about what happens when you turn it off...
It don't matter...
Most of that, is just unspent fuel from the last cycle, blowing up in the hot pipe...
You can jet yer' butt off to make it go away... but, then you'll be jetting to stop instead of to run...
Running is more important... Wink

...

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nickthe_human

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Re: carb adjustments....and backfire
Reply #8 - 05/09/14 at 08:19:08

I still get a soft whoomp on shutoff sometimes. If I am wanting to be quiet, and feel like taking the time, I pull the choke out, and hit the kill switch. this prevents the after fire. I read that on here somewhere. not sure who gave that advice but it worked. usually i'm just lazy and dont care though. Grin

and what Serowbot said, as long as it runs good!

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Re: carb adjustments....and backfire
Reply #9 - 05/09/14 at 08:42:22

Got stopped last night due to the "after fire"...

Had to chop the throttle shut when some drunk dude in the 'hood pulled out too far, got by him on the inside (sidewalk), back in the lane and got on it. It was apparently shooting "torch tip like" flames out the muffler...

Police officer pulled me over to see if both the bike and I were alright. Motor officer, said he was amazed that I didn't lose it going around the car. Cool

No warning! No ticket!! Cool

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HAPPYDAN

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Re: carb adjustments....and backfire
Reply #10 - 05/09/14 at 09:03:34

Rembrandt wrote on 05/08/14 at 19:11:31:

Should I be concerned then? My bike sounds at least as loud as a firecracker, if not a gun upon pretty much every shut down. Does this damage something? I've come to enjoy watching people jump out of their boots at gas stations.

Here in Western Washington that can get you arrested (or shot!). I have learned to pull the choke all the way out and let the engine stumble for a few seconds then switch off. That seems to prevent that "gunfire" report.

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old_rider Serious Thumper Offline Backyard Bill Productions Posts: 3147 flordia panhandle Gender:	Re: carb adjustments....and backfire Reply #11 - 05/09/14 at 13:13:13 I get pops and growls on quick throttle movements and high speed downs shifts, but hardly ever get anything on shutdown. I usually let it idle for about 20-30 seconds at about 1500rpm and just shut off the key....
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Dave YaBB Moderator ModSquad Offline SuzukiSavage.com Rocks! Posts: 18099 Camp Springs, Kentucky Gender:	Re: carb adjustments....and backfire Reply #12 - 05/09/14 at 13:17:12 old_rider wrote on 05/09/14 at 13:13:13: I usually let it idle for about 20-30 seconds at about 1500rpm and just shut off the key.... Same here.....just a brief idling session usually allows the exhaust to cool down enough that I don't get the shut down "poof".
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Bluesman Full Member Offline Jack of many trades Posts: 108 Malmö, Sweden Gender:	Re: carb adjustments....and backfire Reply #13 - 05/09/14 at 13:21:29 I have never had the backfire @ shutdown for some magic reason.
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Jsud04 Full Member Offline SuzukiSavage.com Rocks! Posts: 223	Re: carb adjustments....and backfire Reply #14 - 05/10/14 at 09:02:44 Soooo, Does, can anyone post a video of the proper idle speed...I don't hav a tac and I find myself nervous about this'in
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