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Discussion Starter #1
I recently had my bike at a dealer who checked the CO2 level, he had to drill out the old exhaust plug and replace it with a new one. After driving hundreds of miles around Scotland and returning home, I was changing my round cans back to the oval ones I normally run when the panniers are removed; and noticed a hole in the pipe where the plug should have been. I guess he didn't put thread lock on it, but have had to put a large bolt in the hole not threaded with a jubilee clamp to hold it in to stop the gases escaping.
My question is what thread and pitch size is this bolt as I can't find it in the torque setting of the service manual? this is an ST2 BTW.
I have one on an old set of down pipes I have but no amount of penetrating lub and an impact driver will shift it. The rear plug from the vertical cylinder is a different size as this one I could remove but it is smaller in diameter.
I'd like to fit one with a hexagonal head as I'd have more chance of removing it in future if it got stuck again.
 

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I recently had my bike at a dealer who checked the CO2 level, he had to drill out the old exhaust plug and replace it with a new one. After driving hundreds of miles around Scotland and returning home, I was changing my round cans back to the oval ones I normally run when the panniers are removed; and noticed a hole in the pipe where the plug should have been. I guess he didn't put thread lock on it, but have had to put a large bolt in the hole not threaded with a jubilee clamp to hold it in to stop the gases escaping.
My question is what thread and pitch size is this bolt as I can't find it in the torque setting of the service manual? this is an ST2 BTW.
I have one on an old set of down pipes I have but no amount of penetrating lub and an impact driver will shift it. The rear plug from the vertical cylinder is a different size as this one I could remove but it is smaller in diameter.
I'd like to fit one with a hexagonal head as I'd have more chance of removing it in future if it got stuck again.
Is the threaded insert gone too? If so, you'll need to have a new rivnut installed. Maybe a muffler shop or an engine tuner can help you with that.
 

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Life is too short to worry !
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Hi Tim , Welcome home.

If DG fitted the plug then just give them a call and I'm sure they will send a replacement. Should not have needed threadlock but did need to be tight so its their problem.

You could try , if you havn't already , heating just the pipe to expand the thread on your other pipes ?
Strange that the hori and vert are different , mine are the same...
 

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Discussion Starter #4
If DG fitted the plug then just give them a call and I'm sure they will send a replacement. Should not have needed threadlock but did need to be tight so its their problem.

You could try , if you havn't already , heating just the pipe to expand the thread on your other pipes ?
Strange that the hori and vert are different , mine are the same...
Hi Allan,
They're shut on Monday so haven't been able to contact the mechanic who did the job, I'll contact him tomorrow and see how it goes.
I'll see if I've got any gas in the blow torch an try that on the pipe.
 

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Life is too short to worry !
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Tim - How did you get on with DG ?
 

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Discussion Starter #6
They sent me a replacement which arrived next day which was good.
He said he had re-tapped the hole with a 10x1mm thread size, not sure if this was the original thread size though.
 

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I'm pretty sure the original thread pitch is 0.9! We measured a couple bolts (from the ST3 and a Moster) and kept coming up with that pitch. That's a rare one. We still can't find a tap for mine! May have to retap to a different size!
 

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Discussion Starter #8
I'm pretty sure the original thread pitch is 0.9! We measured a couple bolts (from the ST3 and a Moster) and kept coming up with that pitch. That's a rare one. We still can't find a tap for mine! May have to retap to a different size!
Perhaps that's why the plug fell out after the service and my ride around Scotland, it doesn't re-tap to well or wasn't done up properly!
I'll let you know if the replacement stay's in, and I've put it in myself.
 

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Discussion Starter #10
I'm pretty sure the original thread pitch is 0.9! We measured a couple bolts (from the ST3 and a Moster) and kept coming up with that pitch. That's a rare one. We still can't find a tap for mine! May have to retap to a different size!
You're right I just got hold of a pitch gauge on it and the rear down pipe plug 78020011A plug bolt does measure 0.9 pitch, so much for DG saying they they re-tapped it 10x1 !

That doesn't help me with the lower front pipe though, as I've purchased a plug M12x1.25 and that doesn't fit the thread. It looks the right size M12 but it must be a 1mm pitch, trying to find an M12x1 bolt now to try.
Trying to put a thread gauge into a hole and see if it is fitting into the thread is impossible, it's easier to check on the bolt but I don't have one, yet.
I'll post back when I've got one.

Has anyone had both plugs out before and were they the same size?
Not sure if mine has been modified, but the none chromed front pipe I have I can't get the plug out of so can't measure it. Frustrating as hell.
I'll have to get some gas for the torch, and try heating it before whacking it with the impact driver to loosen it up. I tried that without heat but it's not shifting.
 

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Discussion Starter #11
Turns out it was a 10 x 1 mm thread on the front pipe, nightmare trying to find a bolt shop or ebay selling the right size. I ordered a 10 x 1 and when it arrived it didn't fit, so purchased a thread gauge only to find they had shipped me a 1.25 pitch but they exchanged it with a 1 mm pitch and when I screwed it in found it jumping the thread when tightening up.
Not sure what's up with these bolts or if the thread isn't quite right after DG re-tapping it from 0.9 mm pitch to 1 mm pitch but resorted to putting in a spare oil sensor which turns out to be the right thread size, It looks a bit odd sticking out of the pipe as it's the NAPA type with a big spade connector on it and a 26 mm nut size.
It'll do to plug the hole until the right bolt can be sourced.
 

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I've lost two of these, in spite of using red threadlock. I brought one of my OEM exhaust pipes to a fastener supplier, and they didn't have anything the right size. I haven't lost one for about 3 years now, but on the last one I replaced, I tightened the plug every weekend for about a month after initial installation. Not sure if you have a supplier like Motowheels over in the UK, but they are selling them if your dealer doesn't have them.

DUCATI Exhaust Plug
 

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Turns out it was a 10 x 1 mm thread on the front pipe, nightmare trying to find a bolt shop or ebay selling the right size. I ordered a 10 x 1 and when it arrived it didn't fit, so purchased a thread gauge only to find they had shipped me a 1.25 pitch but they exchanged it with a 1 mm pitch and when I screwed it in found it jumping the thread when tightening up.
Not sure what's up with these bolts or if the thread isn't quite right after DG re-tapping it from 0.9 mm pitch to 1 mm pitch but resorted to putting in a spare oil sensor which turns out to be the right thread size, It looks a bit odd sticking out of the pipe as it's the NAPA type with a big spade connector on it and a 26 mm nut size.
It'll do to plug the hole until the right bolt can be sourced.
The oil switch has a diaphragm of some sort in it. It would bet that it will burn through quickly.

Have a good one.
 

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Discussion Starter #14
The oil switch has a diaphragm of some sort in it. It would bet that it will burn through quickly.

Have a good one.
I put a self tapping screw up the middle of it as I wasn't sure it could take any heat / soot up the tube.
 

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Hello

The bungs in my headers were tapped with a NPT (National Pipe Thread) "Fine" pitch in like 1/4" size. That surprised me, I was expecting a metric thread pitch, but basically just common American 1/4" plumbing threading (except the "fine" pitch part) and I may have the size wrong, just going off memory here...
 
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