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Administrator - "Loose Nut" - Houston, Texas
2001 Vstar 1100 Classic (sold), 2006 HD Electra Glide Ultra Classic
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Discussion Starter · #1 ·
Tire Wheel Helmet Vehicle Automotive lighting


An employee of mine just bought a bike. It's a ragged out Suzuki C50. Appears it spent a lot of time in Galveston and everything has surface rust on it. But he's proud of it. It's got some kind aftermarket exhaust that's super loud. Everytime he decelerations the popping almost sounds like a machine gun. So today after work I told him I would take a look. Has stock air box. Both header pipes were loose, tightened them up. Sprayed some brake cleaner around intake, no leaks. So I take the bike for a run around the block. There's some popping still, but not bad at all. He's all smiles now. So he takes it out and I could hear him and the exhaust was popping bad. So we go from almost no popping to machine gun popping. Only one difference, the rider. When I ride someone else's bike, I'm conservative on up and down shifting. He downshifts very early and slams the throttle shut at each shift. I had him try down shifting a little later and not slamming the throttle shut so quickly. He goes out and comes back and there's almost no popping. I then explain to him what's happening. When you slam the throttle shut with higher RPMs there's still enough vacuum to suck large amounts of fuel into the combustion chamber, to much to fully burn. That fuel rich mixture then goes into the exhaust, hitting the hot pipes and ignites causing the popping. This has been talked about here before but couldn't find it. There's been a few threads lately talking about popping with aftermarket exhaust. The popping is there with stoch exhaust, you just don't hear it. So if you put aftermarket exhaust on, have everything set right, maybe, just maybe, it's your driving style. How about a few of y'all that have some popping try down shifting a little later and don't close you throttle all the way and report back.
 

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I'm not a mechanic so I'll have to assume your diagnosis of the problem was correct; especially if it solved his problem. I'll also assume you didn't have your camera with you when working on his bike. I say this, because looking at the picture you've posted, its plain to see that, that bike is not a Suzuki. I say this with a good amount of certainty. The bike in the picture is clearly outfitted with an afterburner and I know for a fact the C50 can not handle one.

@lesblank, we're not that stupid. We can tell when you're trying to pull a fast one on us.:giggle:
 
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Administrator - "Loose Nut" - Houston, Texas
2001 Vstar 1100 Classic (sold), 2006 HD Electra Glide Ultra Classic
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13,905 Posts
Discussion Starter · #3 ·
The picture was to draw attention and as a joke, no, it was not the bike I was working on. I was just simply explaining how the venturi effect of pulling a rich fuel mixture upon deceleration will cause an exhaust to pop especially with aftermarket exhaust and a way to eliminate most of it. There are several good articles on the effect if it's googled.

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My comment was also meant as a joke. I guess something gets lost in the translation when you need to read it rather than hear it. That picture still makes me think of an afterburnner though. I remember watching F4s take off at night with the afterburner engaged. That's something to see.
 
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2005 V-Star 1100 Classic
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Les found that rare photo of me, Sunday morning after a Triple Threat burrito Saturday night. I was on my way to church - I don't go to that church anymore.
 

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V Star 650 Classic
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why do you guys hate the backfire and pops? mine when it does it give me a huge smile lol well unless there's a police car next to me in that case it give me brown pants lol
 

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why do you guys hate the backfire and pops? mine when it does it give me a huge smile lol well unless there's a police car next to me in that case it give me brown pants lol
Because that means it's not running efficiently and usually unburnt gas from running rich.
To me, it sounds ghetto.
 

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Excellent info and thanks for sharing!

I, for one, from time to time dig the popping. It's a little harder on my bike to be as predictable with it, but I've been slowly dialing in the process to fully control it. In general, I don't have any popping when riding normal but if traffic is pi$$ing me off, I start getting louder and start forcing the pop to happen. It's definitely easier to control on cooler mornings than on warm afternoons but generally, it's fairly controllable.

Also, love the attention pic! I should hook up my Not-A-Flamethrower and ride through LA traffic with it wide open! 🤣🤣🔥
 
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