Air leaking IN or exhaust leaking OUT ?
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From: North Carolina
Air leaking IN or exhaust leaking OUT ?
If there's a small leak at the exhaust port/header pipe junction, does exhaust gas leak out at the port OR does outside fresh air get vacuumed IN to the header pipe. HINT: Seems exhaust pressure would push exhaust gas OUT the small leak, BUT in order to create popping on deleration due to such a leak, seems that extra oxygen must be added to the mixture. MY guess: outside air is being vacuumed into the small leak. Anyone know for sure? Does exhaust escape during accleration and then fresh air comes in during decleration? Is there a test to determine if there's a exhaust port leak?
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From: southeast PA
With the motor running, hold something smoking close to where you think the leak is. Some items that are good for creating thicker smoke are cigars and incense. You'll see where the smoke is blown away from the leak. If it's the exhaust you will need to tighten the nuts on the studs- check them all.
Popping can occur if there is a leak where the mufflers are clamped to the header pipe.
You may also have an intake leak, and to check that you can carefully spray some carb cleaner at the intake manifold with it running. (you can also use a propane torch). If there is a change in the idle speed, you have a leak. Be careful not to spray into the a/c, that will give you a false result.
Your popping can also be caused by the tuning of the bike, with or without any leaks.
Popping can occur if there is a leak where the mufflers are clamped to the header pipe.
You may also have an intake leak, and to check that you can carefully spray some carb cleaner at the intake manifold with it running. (you can also use a propane torch). If there is a change in the idle speed, you have a leak. Be careful not to spray into the a/c, that will give you a false result.
Your popping can also be caused by the tuning of the bike, with or without any leaks.
Last edited by nevil; Nov 25, 2009 at 12:37 PM. Reason: omission
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From: Vancouver
Actually it is both, there is a momentary pause between exhaust pulses when oxygen will be drawn in, on newer bikes with a o2 sensor this can fool the ECM depending on how serious the leak is. I usually will run my hand near where I think the leak is ,You will feel the exhaust pulses, just be VERY CAREFUL not to touch any thing. Having someone help and put rages over the ends of the mufflers will help force exhaust out of a leak making it easier to find.
Last edited by TFTCAR; Nov 25, 2009 at 03:13 PM.
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Jus' remember, it is always based on 'energy'.
Darkness is nothing more, than a lack of "light".
Likewise, cold, is a lack of "heat" energy.
THIS is what confuses the chit outta peeps, when you try to 'edumacate' them, on geothermal heating and cooling systems.
"Well, how can that 53* H2O, 'heat' the air in the house???"
OOPS, OP, you can get BOTH, as posted.
Likewise, the 'popping', can be traced to more than one, prob.
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If there's a small leak at the exhaust port/header pipe junction, does exhaust gas leak out at the port OR does outside fresh air get vacuumed IN to the header pipe. HINT: Seems exhaust pressure would push exhaust gas OUT the small leak, BUT in order to create popping on deleration due to such a leak, seems that extra oxygen must be added to the mixture. MY guess: outside air is being vacuumed into the small leak. Anyone know for sure? Does exhaust escape during accleration and then fresh air comes in during decleration? Is there a test to determine if there's a exhaust port leak?
With that aside, decel popping can be cured by removing fuel in the zero throttle position in the lower rpm ranges. (sometimes adding fuel will also cure the problem). It's not that often that sealing a leak solves decel pop.
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Actually it is both, there is a momentary pause between exhaust pulses when oxygen will be drawn in, on newer bikes with a o2 sensor this can fool the ECM depending on how serious the leak is. I usually will run my hand near where I think the leak is ,You will feel the exhaust pulses, just be VERY CAREFUL not to touch any thing. Having someone help and put rages over the ends of the mufflers will help force exhaust out of a leak making it easier to find.