Exhaust Manifold loose?
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2019 GTS 300 HPE Touring
Joined: 25 Dec 2019
Posts: 1
Location: Sacramento California
Sun Feb 09, 2020 9:14 am quote
I purchased a 2020 300 GTS HPE Touring recently and upon doing my weekly safety inspection I noticed the exhaust manifold did not look right. There is a significant gap between the manifold and the engine and there doesn't appear to be a gasket between the pieces of metal. It is my limited understanding that any time you have to pieces of metal come together there should be a gasket between the two pieces. I was wondering if this is true for the exhaust system on the Vespa. However more concerning is that the gap is not consistent which makes the manifold crooked. Also the bolts connecting the manifold to the engine do not appear to be loose. Could this have been installed like this?

20191230_161940.jpg

Veni, Vidi, Posti
GTS 300ABS, Buddy 125, Buddy Kick 125
Joined: 29 Dec 2007
Posts: 11037
Location: Oregon City, OR
Sun Feb 09, 2020 9:39 am quote
Here is the parts catalogue and exploded parts diagrams for the HPE at AF1.

https://www.af1racing.com/store/ProdImages/st3/EVGP000US9.pdf
Hooked
2005 Vespa LX 150, 2005 GT 200
Joined: 13 Sep 2016
Posts: 294
Location: Hackettstown, New Jersey
Sun Feb 09, 2020 9:39 am quote
Does it leak? Youd know it if you had an exhaust leak. There is usually an internal crush gasket that makes the seal between the pipe and manifold. Looks no different than my GT 200s exhaust pipe to manifold junction.
Hooked
GTS 300ie Touring
Joined: 03 Jun 2018
Posts: 366
Location: Limassol, Cyprus
Sun Feb 09, 2020 10:02 am quote
In my opinion the exhaust manifold has not been tightened-up correctly. There is no gasket between the manifold and the engine, but there should also not be a gap where the two meet.

Tightening the 2 exhaust bolts is very fiddly and requires the use of a wobble ratchet extension. The nuts only need tightening to 12 to 13 Nm = 8.8 to 9.5 ft-lbs, otherwise the bolts can snap off inside the engine housing.

If you decide to do it yourself, make sure you loosen off the muffler mounting bolts first so that you do not put undue strain on the header pipe bolts.

As your scooter is new and still under warranty, I would return it to your dealer and get them to readjust the header pipe connection.

Andrew
Addicted
2009 LX 150, 2008 GTS 250
Joined: 19 Jun 2011
Posts: 730
Location: Birmingham, Alabama, USA
Sun Feb 09, 2020 6:57 pm quote
If I understand your question correctly, there is a copper ring exhaust gasket up in the cylinder head. You push the end of the head pipe against this copper gasket to make the exhaust seal. You do this by tightening the flange with the two nuts. So the gap between that flange and your cylinder head is normal.

Bill
Ossessionato
2016 Vespa GTS300ie abs/asr/ess Settantesimo '70'
Joined: 11 Jun 2011
Posts: 2380
Location: Starfleet Command Engineering, Southern UK HQ,
Sun Feb 09, 2020 7:59 pm quote
Re: Exhaust Manifold loose?
badblackbishop wrote:
I purchased a 2020 300 GTS HPE Touring recently and upon doing my weekly safety inspection I noticed the exhaust manifold did not look right. There is a significant gap between the manifold and the engine and there doesn't appear to be a gasket between the pieces of metal. It is my limited understanding that any time you have to pieces of metal come together there should be a gasket between the two pieces. I was wondering if this is true for the exhaust system on the Vespa. However more concerning is that the gap is not consistent which makes the manifold crooked. Also the bolts connecting the manifold to the engine do not appear to be loose. Could this have been installed like this?
How many miles do you have on her? Has she had the first service yet?

If so, on the first service, it's not uncommon for mechanics to check the tightness of those manifold bolts and wrench them up a bit, and often unevenly which makes the manifold look incorrectly fitted. On mine they overtightened them quite a lot so I had to sort them out as the studs were under extreme pressure. There is no gasket visible either. It's mounted internally, it's a copper ring as someone has already said.

But yours looks fine. No different to my 2016 GTS300. It's common for the manifold pipe bracket to look a bit crooked or the bolts to be tightened slightly unevenly.

Question: Does the bike backfire or make other noises on the overrun (when you are riding or slowing with the throttle closed for example). As long as it's not doing that, it's unlikely to be leaking so don't worry.

If on the other hand you are concerned about it still, then pop into your dealer for a chat about it, but it's probably fine from what I can see.
Veni, Vidi, Posti
Lx 50 4T, GTS 250, Something Chinese
Joined: 21 Feb 2011
Posts: 7709
Location: KS USA
Mon Feb 10, 2020 8:58 am quote
Try unscrewing the silencer slightly from the swingarm. Next loosen up a little bit on the clamp securing the graphite gasket. Then tighten up the bolts on the manifold. Repeat in the reverse order.
Ossessionato
2016 Vespa GTS300ie abs/asr/ess Settantesimo '70'
Joined: 11 Jun 2011
Posts: 2380
Location: Starfleet Command Engineering, Southern UK HQ,
Tue Feb 11, 2020 2:25 am quote
Max6200 wrote:
Try unscrewing the silencer slightly from the swingarm. Next loosen up a little bit on the clamp securing the graphite gasket. Then tighten up the bolts on the manifold. Repeat in the reverse order.
Would strongly suggest he doesn't do that while the bike is under warranty. If the nuts have already been re-tightened at the first service, the studs are likely to shear off. They break really easily as they are through hardened. They are not a high torque stud. We don't yet know if the bike has had it's first dealer service. If it has the bolts will almost certainly have been re-tightened (should just be checked for tightness but some techs go mad with these and wrench them up). Totally not needed.

Repeat, the OP's manifold bracket looks fine, at least from the photo, and no different to most other new bikes you will see in the showroom.
Veni, Vidi, Posti
Lx 50 4T, GTS 250, Something Chinese
Joined: 21 Feb 2011
Posts: 7709
Location: KS USA
Tue Feb 11, 2020 6:16 am quote
Stromrider wrote:
Max6200 wrote:
Try unscrewing the silencer slightly from the swingarm. Next loosen up a little bit on the clamp securing the graphite gasket. Then tighten up the bolts on the manifold. Repeat in the reverse order.
Would strongly suggest he doesn't do that while the bike is under warranty. If the nuts have already been re-tightened at the first service, the studs are likely to shear off. They break really easily as they are through hardened. They are not a high torque stud. We don't yet know if the bike has had it's first dealer service. If it has the bolts will almost certainly have been re-tightened (should just be checked for tightness but some techs go mad with these and wrench them up). Totally not needed.

Repeat, the OP's manifold bracket looks fine, at least from the photo, and no different to most other new bikes you will see in the showroom.
Without the slightest hint of irony, I can tell you this:

It's always a pleasure when somebody corrects me. I am not a technician, just an amateur giving amateur advice. I'm glad you're here to keep me on my toes!
Ossessionato
2016 Vespa GTS300ie abs/asr/ess Settantesimo '70'
Joined: 11 Jun 2011
Posts: 2380
Location: Starfleet Command Engineering, Southern UK HQ,
Wed Feb 12, 2020 12:56 am quote
Hi Max, sorry not meant in any way to be a slur on your advice, which I have to say is normally pretty good. Just don't want him to snap an exhaust stud. He'd have to pay for that himself if he did and being an engine out job it's expensive. It's quite normal for exhaust manifold brackets to look a bit squiffy on some bikes! It makes no difference to anything...Lol...
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