Front exhaust header off

[gilson]

Hi all,

At Snetterton yesterday I was experiencing some exhaust pops on deceleration so I tightened the can end clamps thinking air was getting in at that point. I was partially right.

As I just entered the back straight off came the from exhaust header! Fortunately I cruised up the straight and pulled off, not stopping the session.

I think I was lucky as this studs didn't snap. Am I right in thinking the nuts must have just worked themselves loose, or rusted/disintegrated?

Is there a risk to the exhaust valves? I didn't accelerate but did have to ride up the straight.

It currently isn't aligned correctly so I'm thinking to remove the exhaust and line it back up before reattaching it. Is there anything else I should consider? Is there a gasket required?

Thanks in advance.

(Excellent evening session. Apparently Bradley Smith was there. He went past me as if I was standing still. Incredible speed.)

[Jamoi]

That's unusual!

Generally those nuts seize up, rather than work loose, have they been undone in the last year or two? Are you missing both nuts?

Do you still have the exhaust manifold clamp? (The flat flange bit which goes under the nuts).

Probably worth ordering new manifold gaskets and perhaps the lower graphite gaskets, then loosen everything up, fit new gaskets, loosely fit the whole system and when you're happy with the alignment, clamp it all up.

I used a thin smear of hi temp silicone on the lower graphite gaskets to help them seal.

**Also** I doubt you'd do any damage cruising back to the pits with a disconnected header.

[gilson]

That's unusual!

Generally those nuts seize up, rather than work loose, have they been undone in the last year or two? Are you missing both nuts?

Do you still have the exhaust manifold clamp? (The flat flange bit which goes under the nuts).

Probably worth ordering new manifold gaskets and perhaps the lower graphite gaskets, then loosen everything up, fit new gaskets, loosely fit the whole system and when you're happy with the alignment, clamp it all up.

I used a thin smear of hi temp silicone on the lower graphite gaskets to help them seal.

**Also** I doubt you'd do any damage cruising back to the pits with a disconnected header.

Excellent, thank you Jamoi.

Both nuts have come off and both studs are still present. The clamp is there, it's just fallen down the header. It's a little wobbly so, as you said, once it's all loose it should line back up.

When you refer to graphite seals are those on the original exhaust (I've saw those when I replaced them) at the can end section or are there similar seals for the engine end?

Noted the use of high temp silicone. Thanks.

[fabiostar]

most folk have problems getting those nuts to loosen

[8541Hawk]

While the header is off here are a couple tips..... http://vtr1000.org/phpBB3/viewtopic.php ... 369381c564

[gilson]

most folk have problems getting those nuts to loosen

I've read that these studs often snap off. This was my first thought. It could have been a lot worse.

[gilson]

While the header is off here are a couple tips..... http://vtr1000.org/phpBB3/viewtopic.php ... 369381c564

Excellent, thank you for posting.

[tony.mon]

You won't have damaged anything running it like that for a few minutes.

[gilson]

You won't have damaged anything running it like that for a few minutes.

Brilliant, thanks. When I came off I actually thought someone hit me from behind. It was quite a shock.

[KermitLeFrog]

I'm actually almost pleased with this. When I fitted new studs and nuts I used a special high temperature anit-sieze (Depac metal free) and when ever I removed the nuts I re-applied it. It's white and you will notice it's still on the rear exhaust studs. Better check those as well.

Sent from my SM-T875 using Tapatalk

[gilson]

I'm actually almost pleased with this. When I fitted new studs and nuts I used a special high temperature anit-sieze (Depac metal free) and when ever I removed the nuts I re-applied it. It's white and you will notice it's still on the rear exhaust studs. Better check those as well.

Sent from my SM-T875 using Tapatalk

Thanks Ian. I noticed that white stuff. I'll definitely check them when I put them back on. I'm really enjoying the bike.

[mjvw]

That's unusual!

Generally those nuts seize up, rather than work loose, have they been undone in the last year or two? Are you missing both nuts?

Do you still have the exhaust manifold clamp? (The flat flange bit which goes under the nuts).

Probably worth ordering new manifold gaskets and perhaps the lower graphite gaskets, then loosen everything up, fit new gaskets, loosely fit the whole system and when you're happy with the alignment, clamp it all up.

I used a thin smear of hi temp silicone on the lower graphite gaskets to help them seal.

**Also** I doubt you'd do any damage cruising back to the pits with a disconnected header.

Excellent, thank you Jamoi.

Both nuts have come off and both studs are still present. The clamp is there, it's just fallen down the header. It's a little wobbly so, as you said, once it's all loose it should line back up.

When you refer to graphite seals are those on the original exhaust (I've saw those when I replaced them) at the can end section or are there similar seals for the engine end?

Noted the use of high temp silicone. Thanks.

I found the seal below the rear header (lower seal to main exhaust assembly behind rear shock linkage) difficult to seal after two attempts this
worked....using a new graphite seal and cleaning surface of header and connecting pipe with Dremel as mentioned high temp silicone sealant nipped up front cylinder header, fastened rear header, using a car jack under main exhaust gently lifted exhaust so it full engaged the rear header pipe then tightened the exhaust clamp on that connection followed by the rest.

Don't really need much lift the jack is more of a helper.

This worked a treat, the issue I had when doing it without the jack was the last couple of millimeters you could just see the tops of the slots as pipe not fully engaged and these caused the exhaust leak.

I also found graphite seals purchased from M&P better than some of other suppliers (just my opinion after spoiling two gaskets) Had no issues with the round cylinder header crush rings purchased.

[tony.mon]

The problem with fully engaging the header with the rear downpipe is that you can then end up with a different position of each of the can outlets.

The slotted sections are a problem when using Honda or exact equivalents, but if you use a slightly wider clamp you can generally clamp over the slots.

[gilson]

Thanks chaps, much appreciated