Author Topic: How hot is your exhaust?  (Read 611 times)

Online faffi

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How hot is your exhaust?
« on: July 15, 2025, 03:02:36 AM »
My V9 Roamer, likely a 2017 that first hit the road in 2018, have just over 10k miles on it, and ready for its third rear tire. Tire renewal means muffler removal. There is alu foil inside the vanity covers that tidy up the space where the collector/catalyst and mufflers meet, which has turned golden. I tried to get a true picture of the color on the catalyst/downpipe, but the camera will not give an accurate image of just how blue it is. Still, both sides are really blued. I suppose it is normal, but there is definitely a lot of heat being produced, and this heat source is also quite close to the oil pan.



Current bikes:
2018 V9 Roamer
1982 XV750/1100 mongrel
1990 XT600Z
2001 NT650V in bits

Offline blu guzz

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Re: How hot is your exhaust?
« Reply #1 on: July 15, 2025, 06:22:27 AM »
Any catalytic equipped bike will run hot.  I have found the bikes with less perceived heat are the ones with the catalysts in the muffler pipes as opposed to the catalyst being a collection box under the bike as on the small block bikes.  My V85 was pretty hot down there and the V100 I just test rode was as well.  I think the coloration is normal after a few miles.
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Offline JJ

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Re: How hot is your exhaust?
« Reply #2 on: July 15, 2025, 07:46:51 AM »
If I eat too many of these...my exhaust gets "VERY HOT!!"  :laugh: :grin: :wink: :rolleyes: :shocked:



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Online faffi

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Re: How hot is your exhaust?
« Reply #3 on: July 15, 2025, 07:52:19 AM »
 :grin:
Current bikes:
2018 V9 Roamer
1982 XV750/1100 mongrel
1990 XT600Z
2001 NT650V in bits

Offline Moparnut72

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Re: How hot is your exhaust?
« Reply #4 on: July 15, 2025, 09:50:00 AM »
I don't get it guys, of all the Guzzis I own or have owned the V7 and the Mandello do not get hot and I live in California where it gets really hot. My 1400 got fairly warm at times but that heat came from the oil cooler. If you want to see hot, go ride a Harley sometime. My 110" would get so hot I would have to shut it down in stop and go traffic to keep my right leg from being parboiled. I do expect some heat after all our bikes burn gasoline to get us down the road, after all burning dead dinosaurs does create heat.
kk
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Online Perazzimx14

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Re: How hot is your exhaust?
« Reply #5 on: July 15, 2025, 11:22:16 AM »
I don't get it guys, of all the Guzzis I own or have owned the V7 and the Mandello do not get hot and I live in California where it gets really hot. My 1400 got fairly warm at times but that heat came from the oil cooler. If you want to see hot, go ride a Harley sometime. My 110" would get so hot I would have to shut it down in stop and go traffic to keep my right leg from being parboiled. I do expect some heat after all our bikes burn gasoline to get us down the road, after all burning dead dinosaurs does create heat.
kk

I don't know how hot the header on my Buell gets but my right inner thigh and ham seem to think somewhere about the core temperature of the sun.
2021 Moto Guzzi V85TT Guardia D'onore
2017 V7 III Carbon Dark #0008 of 1921
2017 Road Glide Special
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Offline Kiwi_Roy

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Re: How hot is your exhaust?
« Reply #6 on: July 15, 2025, 04:42:03 PM »
The catalytic converter can get extremely hot.
riding in 2018 I pulled up to a light on my 2017 V7III Special, someone tapped me on the shoulder and said "Do you know your bike is on fire"?
Sure enough I looked down and there were flames coming out at the cat location. I tried to bat them out but just burnt the glove I was wearing.
Luckily a lady pulled up beside me and handed out a bottle of water and I was able to cool it down.
When I went to the dealer and complained they found that the throttle body rubber had popped off and the fuel mixture was way rich.
Later I found there was flammable insulation under the muffler trim, I binned that.
The muffler chrome turned straw coloured but it's slowly regaining the original colour
17 V7III Special
76 Convert

Moto Guzzi - making electricians out of riders since 1921

Offline bronzestar1

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Re: How hot is your exhaust?
« Reply #7 on: July 15, 2025, 08:43:00 PM »
I replaced the OEM exhaust on my V100 with a set of Agostini big bore headers and y-pipe, with a Mistral muffler, so there's no big boxy cat underneath the engine anymore.  If bluing is any indication of how hot the exhaust gets, mine is blued right up by the exhaust ports, which one would expect.  But everywhere else looks "normal". 

This is the OEM exhaust, w/o the muffler.  Notice how it's all one-piece, so doing a cat delete would involve some pipe cutting:





Agostini headers / y-pipe and Mistral muffler:


« Last Edit: July 15, 2025, 08:46:43 PM by bronzestar1 »

Online faffi

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Re: How hot is your exhaust?
« Reply #8 on: July 16, 2025, 01:13:17 AM »
Single-wall headers will blue, also on older bikes. Motorcycles from Japan usually came with double, or even triple wall headers, to prevent the chrome from turning blue. These days, chrome is less common, but the metal will still change color if it gets hot enough.
Current bikes:
2018 V9 Roamer
1982 XV750/1100 mongrel
1990 XT600Z
2001 NT650V in bits

Offline Moparnut72

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Re: How hot is your exhaust?
« Reply #9 on: July 16, 2025, 09:22:06 AM »
I took the shields off my pipes shortly after purchase so my pipes are totally in view. There is no bluing on mine. The bike is stock other than cosmetic modifications.
kk
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Offline wirespokes

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Re: How hot is your exhaust?
« Reply #10 on: July 16, 2025, 09:54:13 PM »
Catalytic converters are supposed to run hot - they're burning up unburned fuel from the combustion process.

Be careful and mindful of that - remember it get really hot down there. I recall a BMW rider pulling off the road into some weeds. They caught fire and burned up the bike.

Online Dukedesmo

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Re: How hot is your exhaust?
« Reply #11 on: July 17, 2025, 08:22:48 AM »
Guzzi exhausts cool well IMO due to the engine layout meaning they get a good airflow whilst riding.


I once left my Ducati 916 running for a while in the garage and when I went to it the rear header pipe was glowing orange  :shocked:  and it does get quite warm under your rear end/thighs when in traffic.
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