450 R/T Exhaust Nut

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redcatcher81
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450 R/T Exhaust Nut

Post by redcatcher81 » Mon Dec 06, 2010 2:02 pm

Hello everyone,
I have been occasionally hanging out here where all of the Ducati single knowledge is and trying to find an answer, but no luck. I have searched the forums and nothing comes up when I ask about the torque specs (if it can be measured) for the Exhaust nut on my 450 r/t. I have tightened it as much as I dare and I am still getting air leaking from around the exhaust nut. It runs, but backfires like crazy. Any help would be appreciated. Also, I have tightened it to the point of the nut wrench stretching at the notches. It is the second aluminum one purchased from here, and I can't imagine that the nut is supposed to be that tight. Thinking that something else is needed. Any suggestions? Thanks.

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BevHevSteve
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Post by BevHevSteve » Mon Dec 06, 2010 2:22 pm

um,....... a new gasket? :oops:
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bobnorton
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Post by bobnorton » Tue Dec 07, 2010 12:53 am

Fit new gasket, remove silencer to chassis bolt , support silencer by hand to find best alighnment before tightening header ring.After a brief run repeat proceedure. Check joint with silencer for black marks.Intermittent ignition can give a backfire.If you are sure its the header joint, remove pipe and check pipe flange,nut face ,seat in head and threads.Refit without gasket ,tighten by hand to check if nut can grip the pipe,if so threads go in enough.Joint with silencer is normally the culprit. Some folk use clear bath sealer ,not tried it myself worth a try as its not much use on baths!!

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Craig in France
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Re: 450 R/T Exhaust Nut

Post by Craig in France » Tue Dec 07, 2010 2:16 am

Hi redcatcher81,

Like the previous posters, I think you're barking up the wrong tree. Forget about torque values - it doesn't really work like that and the factory certainly gave no such thing. You just do the nut up tight, but without being stooopid. (And don't forget to lock-wire the nut on).

That said ...

To add to the advice from Steve and Bob, I did have a problem with the exhaust pipe on my SCR. Careful inspection showed that the top flange was welded on in ever so slightly the wrong position, making it impossible to get an airtight seal, even with two gaskets fitted. I changed the pipe (back to the dented one that the bike originally came with, as it goes ;) ); and no air leak.

But first:
1. Fit a new gasket if you haven't done so before (buy a few, btw).
2. Check the tightness of the fit of the pipe and nut in the head. (An old gasket should do for this - no need to waste a new one). Without the silencer attached, the nut should be able to hold the pipe tight. If it doesn't, find out why.
3. Check the silencer-to-pipe joint. As Bob says, if there's any trace of carbon on the pipe at the joint, you know where your leak is. Try a new clamp of the right size - don't over tighten as they can distort. Also, check that the cuts in the silencer - if you have them on a RT? - are properly covering the end of the pipe.

And then get the silicone out ... :)

HTH

Craig

redcatcher81
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Post by redcatcher81 » Tue Dec 07, 2010 3:20 pm

Hi guys,

Thanks for the replies. I was fairly certain that there was no torque spec, just had to ask since I was having trouble. Everyone has mentioned gaskets so I removed the exhaust from my old r/t that I am beginning to restore and there wasn't a gasket. I am the original owner of that bike and the last to see it running, so either it doesn't take one or I need to add one. I will address the seat/mating surface though. The silicone is an interesting Idea, but first I think I'll try the gasket route. I'll need to find a supplier. Do I need to buy a complete gasket set? (I'll have to eventually) or are they available separately? I will toss in some photo's and bio information as soon as time allows.

Thank You for your help.

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BevHevSteve
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Post by BevHevSteve » Tue Dec 07, 2010 3:31 pm

in stock http://shop.bevelheaven.com/detail.aspx?ID=609

thanks in advance 8) for supporting this forum
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Craig in France
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Post by Craig in France » Wed Dec 08, 2010 1:17 am

Yeh, get 'em from Steve - and you could add a new silencer clamp, a spare exhaust ring and even a lock-wire kit at the same time!

Might save a bit on the postage ... :-D

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Eldert
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Post by Eldert » Wed Dec 08, 2010 8:20 am

i see your from Arizona
if you cant get i fixed you might give David a call , he is from Phoenix
and knows a thing or two about vintage ducatis

http://www.ducatiphoenix.com/

Eldert

redcatcher81
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exhaust nut

Post by redcatcher81 » Wed Dec 08, 2010 11:32 am

Thanks for the info guys...I have seen Dave's site, but have not met him. Thanks for the tip. I'm sure it will help on my restoration of my other r/t. I did order some gaskets from Steve..they should help. I'll keep you advised on the outcome.

redcatcher81
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Post by redcatcher81 » Wed Dec 15, 2010 9:01 am

A little follow-up; I received the gaskets from Steve, installed one, kicked it over and it started but I still felt exhaust leak from the area of the front of the fins near the exhaust nut and the cylinder wouldn't hold compression. (whistling from exhaust while kicking it through). Called Dave at Phoenix Ducati and set up a time to bring the bike over for a look. Longer story shortened; found the compression release did not have a gasket and was not closing completely. A little cleanup and gasket pretty much cleared up the leak. Dave was a huge help and has so much stuff I was overwhelmed. Many thanks Dave!! The point of this post is "Buyer Beware". I did not put this bike together, so I am in the dark about how properly it was assembled...turns out a few small things are not as they should be. Learning as I go, I thank all of you for your help.

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Post by BevHevSteve » Wed Dec 15, 2010 9:38 am

My general rule on bikes that I buy [vintage anyways] is the take em apart and put em back together before I ride em. Do ll the maintenance I can along the way, then I know I have a better bike down the road / long term. I guess what I am trying to say is that there is always something wrong / missing etc on a 30 year old bike when you get it no matter what, so I try to find those things and fix em...
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Craig in France
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Post by Craig in France » Thu Dec 16, 2010 2:18 am

redcatcher81 wrote: ... found the compression release did not have a gasket and was not closing completely. A little cleanup and gasket pretty much cleared up the leak. The point of this post is "Buyer Beware". I did not put this bike together, so I am in the dark about how properly it was assembled...turns out a few small things are not as they should be.
Well congrats to you and Dave for finding the cause! I can't pretend I'd have thought of THAT one!

As you say: there's always more than one way for a DPO to stuff up a perfectly good bike ... :-D

Ciao

Craig

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DesmoDog
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Post by DesmoDog » Sat Dec 18, 2010 9:41 am

Hopefully the guy who did the original work didn't rebuild the engine. If he can't even be bothered to put an exhaust gasket in it, what are the chances he got all the shims back in, let alone the correct sizes in the correct locations???

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