Exhaust

chinaguy · 10-12-2008, 09:47 PM

I get a lot of popping from my exhaust as I release the throttle. That's one issue. The other issue is I don't like the sound of the exhaust; it's almost too quiet and cheap sounding, if that makes any sense. The exhaust is stock, except I drilled three 3/16 holes in the end of the pipe.

Would drilling those three holes to a larger diameter improve the sound (it's subjective I know), and would reducing the back pressure reduce the popping?

elroyjetsn · 10-12-2008, 10:10 PM

Popping might be from rich idle mixture. Mine has never popped when off throttle for some reason. Most thumpers seem to though.

Didn't care for the sound of my Viva- very 2 smoke sounding-harsh. I took out the little spark arrestor pipe thing and replaced it with a 1 inch aluminum pipe that has a bunch of holes drilled in it. Sounds almost exactly like a Honda thumper, now. May pack with glass to make it more mellow.

Little less backpressure also helps with acceleration and top end. Too little backpressure and you'll need to rejet to help the bottom end.

katoranger · 10-13-2008, 11:52 AM

Actually the holes probably lean your bike out even more causing the popping on decel. The best way to fix it is to install a larger main jet in the carb.

Not sure about the drilling of holes, but my bike sounds great with the crf150r pipe on it.

You will need to rejet the carb and also the bike is much LOUDER. I also have a UNI filter too.

Allen

IronFist · 10-13-2008, 12:20 PM

When you're riding, try adding some choke at decel. If it stops popping, you are too lean. If your intake manifold is letting in air, that will make you too lean as well. If your exhaust manifold has a leak, cold air can leak in and cause a popping.

If the bike has always done it then it's likely the jets. If it just started happening, the likely culprit is a manifold.

I'm no pro, JMHO, just as a general rule of thumb, not cut in stone, always use caution when taking anonnomous advice, not telling you what to do, I'm just trying to help.

red2003 · 10-13-2008, 12:24 PM

Follow IronFists advice. You either have a lean low speed jet condition (have you done the clip mod???), or an air leak in the exhaust system.

Dragon · 10-13-2008, 08:50 PM

Before you decide that your muffler needs to be louder, consider if you will ever take the bike on long rides. I just came back from a 150-mile ride today; and my ear is still ringing. I was wearing ear plugs also. Ringing ear is bad. It could do permanent hearing damage.

elroyjetsn · 10-13-2008, 09:37 PM

Quote:

Originally Posted by Dragon

Before you decide that your muffler needs to be louder, consider if you will ever take the bike on long rides. I just came back from a 150-mile ride today; and my ear is still ringing. I was wearing ear plugs also. Ringing ear is bad. It could do permanent hearing damage.

I agree. Mine, stock was way too harsh and my ears were always aching after a long ride. It's sounded like a hightly restricted straight pipe sorta. When i took the spark arrestor pipe thing, it was welded to a cup shaped piece of metal that was supposed to direct the exhaust from a hole in a baffle plate into the little tail pipe. But, the cup was way off center leaving a large gap for the exhaust to bypass the baffle.

I forced the new tailpipe directly thru the baffle plate giving a nice seal with it and the baffle now works nicely to quiet things down. At 45-50mph on flat road the engine can barely be heard above the wind noise in my helmet. At 55, it's louder, but not harsh at all.

The Hsun pipe may be defective like mine. You may be able to fix it, or find a quality replacement.

theENIGMATIC · 10-15-2008, 02:34 PM

Yeah my HSUN is pretty loud too.getting louder than it was, probably from some problem Ive been ignoring.its still doesnt bother me at the level of noise its at now though.ah well!

Dragon · 10-15-2008, 09:34 PM

What can cause a bike to sound louder?

elroyjetsn · 10-16-2008, 06:56 AM

Wouldn't be surprised if something has broken loose inside the pipe. The welds i could see in mine looked like tack welds.

Could also mean that your eardrums are getting sore from the regular exposure to harsh noise.

katoranger · 10-16-2008, 07:44 AM

Check also the gasket at the head. Those connection is known to come loose and on my bike the connection from the head pipe to the muffler would come loose.

The internals of the mufflers are known for failure on these too. Mine stock one rattled pretty bad

Allen

tigertamer · 10-16-2008, 08:05 AM

If it was mine, I'd plug the holes back up!

:wink:
Tigertamer

chriseck · 10-20-2008, 05:53 PM

I drilled the holes on the exhaust around the outlet pipe.Sounds much better and picked up about 2mph top end.The poping sound on deceleration is there and was there before the mod.Its not loud enough to be annoying on long rides.2005 Roketa 200-RSM enduro.

elroyjetsn · 10-20-2008, 06:14 PM

Does applying some choke increase or decrease the popping?

chinaguy · 10-20-2008, 11:47 PM

Applying some choke decreases the popping. I think I'm going to move the carb clip down to the bottom notch. It's on the next to the bottom now. I have to use a little choke to start it, so maybe moving the clip will help that too.

10-12-2008, 09:47 PM	#1
chinaguy Join Date: Jun 2008 Location: Central Pennsylvania Posts: 125	Exhaust I get a lot of popping from my exhaust as I release the throttle. That's one issue. The other issue is I don't like the sound of the exhaust; it's almost too quiet and cheap sounding, if that makes any sense. The exhaust is stock, except I drilled three 3/16 holes in the end of the pipe. Would drilling those three holes to a larger diameter improve the sound (it's subjective I know), and would reducing the back pressure reduce the popping? __________________ 2008 HSUN GY 200
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10-12-2008, 10:10 PM	#2
elroyjetsn Join Date: Mar 2008 Location: West Virginia Posts: 629	Popping might be from rich idle mixture. Mine has never popped when off throttle for some reason. Most thumpers seem to though. Didn't care for the sound of my Viva- very 2 smoke sounding-harsh. I took out the little spark arrestor pipe thing and replaced it with a 1 inch aluminum pipe that has a bunch of holes drilled in it. Sounds almost exactly like a Honda thumper, now. May pack with glass to make it more mellow. Little less backpressure also helps with acceleration and top end. Too little backpressure and you'll need to rejet to help the bottom end. __________________ Wayne Wildfire WF300-SP
	0

10-13-2008, 11:52 AM	#3
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	Actually the holes probably lean your bike out even more causing the popping on decel. The best way to fix it is to install a larger main jet in the carb. Not sure about the drilling of holes, but my bike sounds great with the crf150r pipe on it. You will need to rejet the carb and also the bike is much LOUDER. I also have a UNI filter too. Allen __________________ You meet the nicest people on a Honda Clone.
	0

10-13-2008, 12:20 PM	#4
IronFist Join Date: Apr 2007 Location: Toronto Ontario Canada Posts: 2,585	When you're riding, try adding some choke at decel. If it stops popping, you are too lean. If your intake manifold is letting in air, that will make you too lean as well. If your exhaust manifold has a leak, cold air can leak in and cause a popping. If the bike has always done it then it's likely the jets. If it just started happening, the likely culprit is a manifold. I'm no pro, JMHO, just as a general rule of thumb, not cut in stone, always use caution when taking anonnomous advice, not telling you what to do, I'm just trying to help. __________________ IronFist ___________________________________ The "chain" of command is used for beating spammers. ___________________________________
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10-13-2008, 12:24 PM	#5
red2003 Join Date: Jan 2007 Location: Northern Vermont, USA Posts: 1,223	Follow IronFists advice. You either have a lean low speed jet condition (have you done the clip mod???), or an air leak in the exhaust system. __________________ First Chinabike: 2006 Roketa RSX200E Current Chinabikes: 2023 Titan DLX & 2021 Lifan KP Mini w/ 210cc BRT kit, 22 HP!
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10-13-2008, 08:50 PM	#6
Dragon Join Date: Nov 2007 Location: Tejas Posts: 834	Before you decide that your muffler needs to be louder, consider if you will ever take the bike on long rides. I just came back from a 150-mile ride today; and my ear is still ringing. I was wearing ear plugs also. Ringing ear is bad. It could do permanent hearing damage. __________________ Chinabikeless
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10-15-2008, 02:34 PM	#8
theENIGMATIC Join Date: Feb 2008 Posts: 392	Yeah my HSUN is pretty loud too.getting louder than it was, probably from some problem Ive been ignoring.its still doesnt bother me at the level of noise its at now though.ah well!
	0

10-15-2008, 09:34 PM	#9
Dragon Join Date: Nov 2007 Location: Tejas Posts: 834	What can cause a bike to sound louder? __________________ Chinabikeless
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10-16-2008, 06:56 AM	#10
elroyjetsn Join Date: Mar 2008 Location: West Virginia Posts: 629	Wouldn't be surprised if something has broken loose inside the pipe. The welds i could see in mine looked like tack welds. Could also mean that your eardrums are getting sore from the regular exposure to harsh noise. __________________ Wayne Wildfire WF300-SP
	0

10-16-2008, 07:44 AM	#11
katoranger Join Date: May 2007 Location: Altamont, Kansas Posts: 15,103	Check also the gasket at the head. Those connection is known to come loose and on my bike the connection from the head pipe to the muffler would come loose. The internals of the mufflers are known for failure on these too. Mine stock one rattled pretty bad Allen __________________ You meet the nicest people on a Honda Clone.
	0

10-16-2008, 08:05 AM	#12
tigertamer Join Date: Jul 2008 Location: Wheeling, West Virginia Posts: 683	If it was mine, I'd plug the holes back up! :wink: Tigertamer __________________ 07 H-D XL883C 06 LF 200GY-5 Yin and Yang CAUTION Obey The Traffic Regulation. Always Wear a Helmet. Don't Ride After Drinking Wine. Before Operation, Read The Owners Manual Carefully.
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10-20-2008, 05:53 PM	#13
chriseck Join Date: Jun 2008 Location: Palm Harbor Fl. Posts: 52	I drilled the holes on the exhaust around the outlet pipe.Sounds much better and picked up about 2mph top end.The poping sound on deceleration is there and was there before the mod.Its not loud enough to be annoying on long rides.2005 Roketa 200-RSM enduro.
	0

10-20-2008, 06:14 PM	#14
elroyjetsn Join Date: Mar 2008 Location: West Virginia Posts: 629	Does applying some choke increase or decrease the popping? __________________ Wayne Wildfire WF300-SP
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10-20-2008, 11:47 PM	#15
chinaguy Join Date: Jun 2008 Location: Central Pennsylvania Posts: 125	Applying some choke decreases the popping. I think I'm going to move the carb clip down to the bottom notch. It's on the next to the bottom now. I have to use a little choke to start it, so maybe moving the clip will help that too. __________________ 2008 HSUN GY 200
	0