COPING with the Stock Threaded Exhaust-Ring/Flange
Posted: Tue Nov 24, 2009 12:14 pm
____ As most of us already realize, the threaded exhaust-ring pipe-to-head fastener-flange is a fairly poor design on DUCATI's part!
Here's a list of all the related downfalls of the design.....
_ The threaded-ring tends to work loose (due to vibration).
_ It's a real-pain to tighten without bending or busting it's ear-fins, (thus it seems that it can't really be fully tightened) !
_ Every time the threaded-ring comes loose, it then rattles-around & wears-down the threads. _ (More & more so, the longer it's left that way.) _ Not to mention the popping & muted backfire-like sounds which result from a loose ex.pipe-header!
_ Next in sequence,, at some point in the threaded-ring's life, it gets dealt with by an 'Average-joe' who tries to install it cross-threaded, (due to the fact that the threads are too fine for an Average-Jo -[av.jo] to cope with properly). _ Then the av.jo believes that the actual reason that the ex.ring won't tighten-in any further, is: "Kuz it's done gone in az fur as da gosh-dang thang wills goes in thare!" .
So av.jo leaves it that way, and so then the steel lip-flange on the ex.pipe rattles all-around inside on the ex.port-threads and pretty-much destroys most all of the leftover alum.alloy head-threads.
____ The main/root-cause which leads to the above chain-of-events is, that the threaded exhaust ring-flange doesn't actually ever get really tightened fully! _ That's right! _ I'm contending that most all those who think that they've been getting the ex.ring as tight as that stock set-up will go, were actually falling-short of it's true capability!
The prime reason for that, is a combination of (at least) two factors...
_ The lack of a tool which can manage to get some kind of a good & proper grasp of the (stock type) ex.ring! And,
_ The lack of a sufficiant strength & leverage combination, to get the job done nearly as well as it could be!
____ Now here's what can be done to curtail (if not solve) this knuckle-busting issue.....
__ I, (for one), have discovered a method which so greatly increases the 'leverage' factor of the job -(of turning the ex.ring), that no special tool is really needed!
With my method and the use of a simple home-made tool (which grabs only one of the ex.ring's ear-fins at a time),, I've been able to easily tighten, (as well as loosen), the ex.ring so tightly, that it STAYS-PUT exactly where I leave it (tightened at)! _ (Just as most anything else that uses threads will do, when sufficiantly tightened.)
And the process never busts even a single ear-fin! _ (Although I still have bent one, very slightly, while using my particular tool.)
____ My method for turning the ex.ring, is as follows.
__First, for easily getting a tight ex.ring loose,, the muffler must be unbolted from the frame and free to be moved, (if not totally removed).
Next, grab the lower-end of the header-ex.pipe by hand, and cautiously pull it outward & upward, swinging the ex.pipe away from it's normal position next to the motor-case, (thus rotating the ex.pipe-header within the head's ex.port). _ (The ex.pipe should not be so tight in the cyl.head, that this step can't be done, [with care] ! )
Now with your tool (for turning the ex.ring) in place for loosening, begin trying to turn the ex.ring loose while at the same time & same rate of turn, push (swing) the bottom-end of the ex.pipe back down & inward towards it's normal position. ... The ex.ring turns loose EASILY!!
Reposition your ex.ring-tool and the ex.pipe as needed, and repeat the same process until the ex.ring is twistable by hand. _ (You'll find that wiggling the ex.pipe slightly while trying to twist/turn the ex.ring by hand, will allow the ex.ring to rotate more easily! Thus less need for the use of your tool.)
I'll bet that (without the employment of this method), you've never had such an easy job of getting such an ex.ring loose, (that wasn't already too loose) !
__ For tightening the ex.ring to a sufficiant point, (which is fairly beyond the point that's most often reached without using this method),, ya need to properly position your ex-ring-tool and use it to turn/tighten the ex.ring while at the same time swinging the ex.pipe outward & upward, BOTH AT THE EXACT SAME (not too fast) RATE! - (Those of us who understand the 'Coefficient of Friction' will understand why this method works only when both are turned together at the same rate.)
You will definitely notice that your ex.ring-tool will do it's work much more easily! _ (So don't expect to develop the same amount of torque on your tool as you've been used to doing!) _ Hence this method will get it much tighter, even with less force than you're used to having to use against your ex.ring-tool! _ Therefore, quite sufficiant tightening-pressure (between the ex.ring & the head's ex.port-ledge), will likely be reached well before you can no longer continue to turn/tighten the ex.ring (using this method).
Still, I have continued on past the point which is sufficient to make sure that the ex.ring stays put... Pressing-on even until I could no longer even budge the ex.pipe, any at all ! _ And without any notable harm to any of the threads involved! _ I WOULDN'T TRY THAT WITH NOTABLY WORN THREADS (on either part), however!
_Note, I never tried my ex.ring tightening method without using an exhaust-gasket! (Always using either the stock-part or a MotoGuzzi type copper tube-ring.)
____ I really hope that this info will help at least one DUKE-owner to have an easier time dealing with his exhaust-pipe removal/installation!
Your True 'DUKE-Mech' !
DewCatTea-Bob
Here's a list of all the related downfalls of the design.....
_ The threaded-ring tends to work loose (due to vibration).
_ It's a real-pain to tighten without bending or busting it's ear-fins, (thus it seems that it can't really be fully tightened) !
_ Every time the threaded-ring comes loose, it then rattles-around & wears-down the threads. _ (More & more so, the longer it's left that way.) _ Not to mention the popping & muted backfire-like sounds which result from a loose ex.pipe-header!
_ Next in sequence,, at some point in the threaded-ring's life, it gets dealt with by an 'Average-joe' who tries to install it cross-threaded, (due to the fact that the threads are too fine for an Average-Jo -[av.jo] to cope with properly). _ Then the av.jo believes that the actual reason that the ex.ring won't tighten-in any further, is: "Kuz it's done gone in az fur as da gosh-dang thang wills goes in thare!" .
So av.jo leaves it that way, and so then the steel lip-flange on the ex.pipe rattles all-around inside on the ex.port-threads and pretty-much destroys most all of the leftover alum.alloy head-threads.
____ The main/root-cause which leads to the above chain-of-events is, that the threaded exhaust ring-flange doesn't actually ever get really tightened fully! _ That's right! _ I'm contending that most all those who think that they've been getting the ex.ring as tight as that stock set-up will go, were actually falling-short of it's true capability!
The prime reason for that, is a combination of (at least) two factors...
_ The lack of a tool which can manage to get some kind of a good & proper grasp of the (stock type) ex.ring! And,
_ The lack of a sufficiant strength & leverage combination, to get the job done nearly as well as it could be!
____ Now here's what can be done to curtail (if not solve) this knuckle-busting issue.....
__ I, (for one), have discovered a method which so greatly increases the 'leverage' factor of the job -(of turning the ex.ring), that no special tool is really needed!
With my method and the use of a simple home-made tool (which grabs only one of the ex.ring's ear-fins at a time),, I've been able to easily tighten, (as well as loosen), the ex.ring so tightly, that it STAYS-PUT exactly where I leave it (tightened at)! _ (Just as most anything else that uses threads will do, when sufficiantly tightened.)
And the process never busts even a single ear-fin! _ (Although I still have bent one, very slightly, while using my particular tool.)
____ My method for turning the ex.ring, is as follows.
__First, for easily getting a tight ex.ring loose,, the muffler must be unbolted from the frame and free to be moved, (if not totally removed).
Next, grab the lower-end of the header-ex.pipe by hand, and cautiously pull it outward & upward, swinging the ex.pipe away from it's normal position next to the motor-case, (thus rotating the ex.pipe-header within the head's ex.port). _ (The ex.pipe should not be so tight in the cyl.head, that this step can't be done, [with care] ! )
Now with your tool (for turning the ex.ring) in place for loosening, begin trying to turn the ex.ring loose while at the same time & same rate of turn, push (swing) the bottom-end of the ex.pipe back down & inward towards it's normal position. ... The ex.ring turns loose EASILY!!
Reposition your ex.ring-tool and the ex.pipe as needed, and repeat the same process until the ex.ring is twistable by hand. _ (You'll find that wiggling the ex.pipe slightly while trying to twist/turn the ex.ring by hand, will allow the ex.ring to rotate more easily! Thus less need for the use of your tool.)
I'll bet that (without the employment of this method), you've never had such an easy job of getting such an ex.ring loose, (that wasn't already too loose) !
__ For tightening the ex.ring to a sufficiant point, (which is fairly beyond the point that's most often reached without using this method),, ya need to properly position your ex-ring-tool and use it to turn/tighten the ex.ring while at the same time swinging the ex.pipe outward & upward, BOTH AT THE EXACT SAME (not too fast) RATE! - (Those of us who understand the 'Coefficient of Friction' will understand why this method works only when both are turned together at the same rate.)
You will definitely notice that your ex.ring-tool will do it's work much more easily! _ (So don't expect to develop the same amount of torque on your tool as you've been used to doing!) _ Hence this method will get it much tighter, even with less force than you're used to having to use against your ex.ring-tool! _ Therefore, quite sufficiant tightening-pressure (between the ex.ring & the head's ex.port-ledge), will likely be reached well before you can no longer continue to turn/tighten the ex.ring (using this method).
Still, I have continued on past the point which is sufficient to make sure that the ex.ring stays put... Pressing-on even until I could no longer even budge the ex.pipe, any at all ! _ And without any notable harm to any of the threads involved! _ I WOULDN'T TRY THAT WITH NOTABLY WORN THREADS (on either part), however!
_Note, I never tried my ex.ring tightening method without using an exhaust-gasket! (Always using either the stock-part or a MotoGuzzi type copper tube-ring.)
____ I really hope that this info will help at least one DUKE-owner to have an easier time dealing with his exhaust-pipe removal/installation!
Your True 'DUKE-Mech' !
DewCatTea-Bob