I swear it's an exhaust leak because it sounds funny but not being mechanically inclined I thought I'd ask for help/input from you guys so I can start shaking down the bike.
I have an 06, S4R with about 7,500 miles. She's only popped when it gets below 40 so I thought maybe she's running lean, and I haven't changed the sparkplugs either.....yet.
let'r rip
Exhaust leaks were pretty common on those bikes.
I believe it was the front header to pipe gasket...
this link should help...http://ducatimonsterforum.org/index.php?topic=12501.0 (http://ducatimonsterforum.org/index.php?topic=12501.0)
Did it just start popping recently, or has this problem been around for a while?
this is the second time and last ride it did it once or twice. this time more pronounced. I've never had an issue with it before.
poor air fuel ratio. can happen especially with aftermarket slip-ons.
happens on my S3 all the time
but it's never been a problem before so I can't imagine it's a fuel/air mixture.
What do you guys recommend to seal the pipes? Was thinking of some teflon tape or teflon packing by the slip ons but what do you do by the front cyl head?
Quote from: battlecry on January 04, 2010, 03:28:16 AM
What do you guys recommend to seal the pipes? Was thinking of some teflon tape or teflon packing by the slip ons but what do you do by the front cyl head?
You can use High temp Copper RTV on any slip joints and the headers have gaskets which you could replace and add RTV if you are paranoid about them leaking again.
I had this crop on my 620 after a while... just loosening the connections, giving it a wiggle and re tightening everything sorted it.
Sounding funny - check the little plugs in the exhaust. My bikes have had one for each cylinder, I think they are for testing exhaust gasses. I've had them come out - lost on the road somewhere and when they are gone, it will sound funny and pop on decel.
Quote from: muskrat on January 03, 2010, 06:44:49 PM
but it's never been a problem before so I can't imagine it's a fuel/air mixture.
"running lean" is an air/fuel ratio problem. It is not doing any harm to the engine, unless you do have something loose. but you were saying that is only happens when it is cold, so I do not think it is because something is loose.
Linkie for support (http://wiki.answers.com/Q/Which_has_more_oxygen_hot_air_or_cold_air)
Quote from: JonnyCinco on January 04, 2010, 11:24:40 AM
"running lean" is an air/fuel ratio problem. It is not doing any harm to the engine, unless you do have something loose.
I completely disagree with this statement. Fuel plays a critical role in cooling and lubricating the engines valves, piston walls etc. and a lean running engine is a bad thing risking damage to engine internals and leaving power on the table.
To the OP: What octane are you running? Since this is only doing this when cold you are most likely running lean because as JonnyCinco points out colder air is denser.
Try putting a higher octane fuel in the engine to see if that helps offset some of the popping.
You can also pull the plugs and look them over white is bad - brown is good
I'll loosen and re-tighten to see if that fixes the problem. as for the fuel/air mixture, I run 93 in my tank always.
the octane has nothing to do with your air/fuel mixture... if your bike has an 02 sensor (not running a DP ECU), then try getting a fatduc to richen your mixture.
Quote from: muskrat on January 04, 2010, 03:17:10 PM
I'll loosen and re-tighten to see if that fixes the problem. as for the fuel/air mixture, I run 93 in my tank always.
93 is not needed in our engines under most circumstances.
Do you have an open airbox or slip-ons?
I would be curious to see the plugs or you could just not worry about it...
Quote from: cduarte on January 04, 2010, 03:59:23 PM
the octane has nothing to do with your air/fuel mixture... if your bike has an 02 sensor (not running a DP ECU), then try getting a fatduc to richen your mixture.
Octane does impact air/fuel ratio... Here is a pretty basic description with the formulas etc... http://en.wikipedia.org/wiki/Air-fuel_ratio (http://en.wikipedia.org/wiki/Air-fuel_ratio)
i didn't realize your bike was closed loop... good luck!
popping on decel has nothing to do with octane.
It can be caused by a lean mixture...
an airleak in the exhaust,
or a very rich mixture that explodes in the hot exhaust and shoots flames about 3 feet long.
The last one is cool. [thumbsup]
Quote from: ducpainter on January 04, 2010, 04:40:30 PM
popping on decel has nothing to do with octane.
It can be caused by a lean mixture...
an airleak in the exhaust,
or a very rich mixture that explodes in the hot exhaust and shoots flames about 3 feet long.
The last one is cool. [thumbsup]
I still disagree because AFR is impacted by octane... However, the key distinction and one that I had started to overlook -is popping on decel - if the fault were octane related it would be evidenced by knocking or pinging which happen under load.
Quote from: gage on January 04, 2010, 05:11:15 PM
I still disagree because AFR is impacted by octane... <snip>
I need documentation on that. ;)
Quote from: gage on January 04, 2010, 04:13:34 PM
Here is a pretty basic description with the formulas etc... http://en.wikipedia.org/wiki/Air-fuel_ratio (http://en.wikipedia.org/wiki/Air-fuel_ratio)
see above link.
-The professor
Quote from: muskrat on January 03, 2010, 06:44:49 PM
but it's never been a problem before so I can't imagine it's a fuel/air mixture.
Check to see if the bolts holding the exhaust headers onto the cylinder heads have come loose. My top header bolts get a bit loose about once a year....I know it's happened 'cause the bike makes a nice loud pop on decel once in a while....tighten the bolts and the pop goes away
Quote from: gage on January 04, 2010, 05:32:06 PM
see above link.
-The professor
This article does not cite any references or sources.
not biting. ;D
Quote from: gage on January 04, 2010, 04:13:34 PM
Octane does impact air/fuel ratio... Here is a pretty basic description with the formulas etc... http://en.wikipedia.org/wiki/Air-fuel_ratio (http://en.wikipedia.org/wiki/Air-fuel_ratio)
i didn't realize your bike was closed loop... good luck!
I disagree entirely that octane is a pure regulator of A/F ratio, and the article did not state that. For example, ethanol has a much higher octaune than "Pure" gasoline, however it's BTU content is much lower. Therefore, an alcohol powered vehicle must run much richer in order to produce much power. And the C/R or intake PSI must be dramatically increased to take advantage of the higher octane. I think you are exagerating the effect that a few octane points(that are mostly there from ethanol) can have on the "Effective" AFR.
Wiki is almost correct on the octane/air fuel ratio issue. It all depends on how the octane is built. In the past, with oxygenated fuels (EPA type, not the race type) and the absence of lead to build octane, MTBE and alcohol were often used to raise octane level, thereby leaning the mixture. I have no idea if lead had any effect on mixture.
Quote from: ducpainter on January 04, 2010, 04:40:30 PM
popping on decel has nothing to do with octane.
It can be caused by a lean mixture...
an airleak in the exhaust,
or a very rich mixture that explodes in the hot exhaust and shoots flames about 3 feet long.
The last one is cool. [thumbsup]
Pay attention to what Nate wrote. What you hear is an after burn of unburnt fuel in the exhaust. Introduced air, excessive hydrocarbons and from running too lean or too rich can cause this problem.
no open air box.
have DP ECU, full Termis on bike too.
Will check plugs later today.
found the leak. the mid pipe was the cause, not saying what part :-X