Deceleration "Popping" Noise

[cytechnics]

I have a 2004 Rune with no modifications. For about a year, on deceleration, there is a distinctive “popping” sound from the exhaust, and it is not consistent with heavy deceleration or light. I can’t class it as backfiring. It seems, stress, seems, to be from the right side only. The dealer diagnosis, by two senior maintenance personnel, independently, was a problem with the exhaust gaskets. These were replaced, but the problem remained exactly as before. There are no discernable power issues, the plugs were and are good (just replaced), the air filter is new and drains were cleaned. Electronics were not checked. Timing and valve clearance have not been checked but it is unlikely these items are the source (but you never know), with the bike having less than 30,000 km (less than 18,500 miles) on it, and it has not been driven hard. The manual makes no mention of this as a potential trouble, so the troubleshooting sections are useless. I will not continue with trying to solve it by the "guess and repair and see" method as the cost will quickly mount into the thousands for this bike with no guarantee of a solution. There is also the fact that there are not too many personnel in my area or even in the province with a lot of experience maintaining the Rune. I am assuming that left alone, whatever the source of the problem is, it will get worse and end up resulting in very costly repairs. So .... any ideas?

[MO Rune Rider]

Welcome to the forum.


From what you describe, I'd say it's normal. At least mine does it. My wife has her exhaust cans drilled for louder decibels, and her's has a very prounouncd decel popping. Some people actually enjoy the sound.

[SiteData]

I occasionally experience the same as you’ve mentioned from day one.
My Rune is a 2004 has 20,126 miles and I’ve heard the same on other
Runes I’ve ridden with.

[CrimsonRune]

Originally Posted by SiteData

I occasionally experience the same as you’ve mentioned from day one.
My Rune is a 2004 has 20,126 miles and I’ve heard the same on other
Runes I’ve ridden with.

I have a 2004 with about 4200 miles and get the same thing. I counter it by accelerating more and decelerating less Just kidding. But I think its probably a normal thing to happen

[asacuta]

This is somewhat consistent with an engine that uses air injection into the exhaust to control hydrocarbon emissions. If the problem is bad, it could be a leaky check valve (there are 6: one for each cylinder), a bad solenoid valve, or a plugged line from the airbox. If you're worried, you could check the last two; it would have to be very bad to bother screwing around with the first. See p. 6-58 of the service manual.

Since the problem seems to come from the right, it could be one of the check valves on the right-hand side, or the right side of the control valve is plugged. That is merely a SWAG.

[cytechnics]

Thanks to all that provided feedback on my Rune decel popping sound. I was pleasantly suprised to see responses actually since I'd expected that by now there would be less activity on the site.
I gather that there seems to be a concencus that it (the noise on decel) is normal. I had raised the topic since it had never once occured before in the period from purchase in Sep 03 to roughly May of 09. In all other aspects this motorcycle has caused me not even a shaow of doubt or grief whatsover - quite the opposite. Its still by far my favourite ride and that includes after taking test rides on every other manufacturers' bikes (in the cruiser class) and even my other machines in my "stable" (superbike, touring, sport-touring).

Safe riding to all and I'll be on the other boards more frequently now that I know there are still plenty of other very active Rune riders (too bad there are very few Runes in Canada).

[asacuta]

Originally Posted by cytechnics

(too bad there are very few Runes in Canada).

Varies with province and city. There are 6 within a 15 minute ride from my place; probably a dozen within a 30 minute ride. Len has 2, but he buys at least 2 of everything.

[cytechnics]

Originally Posted by asacuta

This is somewhat consistent with an engine that uses air injection into the exhaust to control hydrocarbon emissions. If the problem is bad, it could be a leaky check valve (there are 6: one for each cylinder), a bad solenoid valve, or a plugged line from the airbox. If you're worried, you could check the last two; it would have to be very bad to bother screwing around with the first. See p. 6-58 of the service manual.

Since the problem seems to come from the right, it could be one of the check valves on the right-hand side, or the right side of the control valve is plugged. That is merely a SWAG.

I just saw your response Al after I finished sneding my second post. I'll go through the manual re your suggestions and see what I can handle in my garage. The sound is quite loud. The word "plugged" in you e-mail makes me wonder if a rodent may have gotten into the machine, although I have always for winter storage stuffed pipes and covered her - but there is no refuting the fact that something might have gotten in, in the early spring of '09 after I started riding after our winter.

Bruce

[RedValk]

my wife's Rune has stock exhaust with no mods (yes, poor pitiful her )...and hers DOES do exactly what you described on decel...and in fact...it's been doing it MORE consistently lately we've both noticed.

my Rune, has the drilled exhaust mod (goody for me )....and as folks with the exhuast mod will tell you, yes, they can pop on decel...even a bit more often than before the mod was done...and...a bit louder too, of course!

point being, both of our Runes do it...one with unmodded exhaust and the other with the mod. So............it IS the consensus.....

as far as activity on this board....there is a TON of activity...and always has been since it's inception! i ought to know, i manage it