I've got a '99 Pegaso 650 which hasn't been running for about 7 years. It's was in a quite a deteriorated state when I got it, i.e. seized carbs, tank full of water, sump full of an ugly fuel/oil mix, I seriously I drained about 5 liters from it.

I've fixed the biggies and finally got it started today, however it's running really rough (no surprises there) but what worries me is the way the headers are glowing. I've been riding for a long time and owned more than a couple of bikes, but I've never seen headers glow like this before.

A quick search of the internet shows number of threads similar to this, the responses vary from 'this is normal noob' to 'tweak the pilot jet to make it run richer'.

What's your opinion, the bike is a 650cc single bore, it runs very rough for about 3 minutes, the temperature gauge shows about 80 C, but exhausts start to glow.

Is this normal?

2 Answers 2


I would say, no, it's not normal under 99% of circumstances and the remaining 1% most likely won't apply (no turbo to get heat soak from, for example).

The clue is probably in it running rough - did you clean/overhaul the carb(s)? If not, chances are that the mixture is way too lean because some passages in the carb are blocked. I'd try to open up the carb, check for deposit and clean it out with a good carb cleaner. If that improves matters but it's not quite there yet, I'd get the carb ultrasonically cleaned.

The other potential issue that might contribute to the exhaust getting this hot is that the timing is off - check that as well.

  • 1
    Good point about the carbs, they were in an awful state, one was badly corroded internally, the other was gummed up and stuck together like glue. Thoroughly cleaned both using degrease and compressed air, but I might try again with some commercial carb cleaner. Which one would you recommend, a spray cleaner or something I can soak them in.
    – Ian Oakes
    Aug 20, 2011 at 21:57
  • If they're that bad, I'd be tempted to skip the carb cleaner and give them an ultrasonic bath. There are places that do carb refurbishment that'd be able to offer this service, or if you're in the US Harbor Freight has some fairly cheap ultrasonic cleaners. That said, I do prefer the carb cleaner in a spray can generally but I think you'll need to soak those carbs if they're as bad as you described. Aug 21, 2011 at 17:27

I have typically replaced my stock exhaust systems with aftermarket race systems.

Many stock exhaust systems have dual-wall designs so you never see the pipe that the exhaust is actually flowing into.

All of my exhaust pipes glow orange/red when I ride them hard. It's fine and completely normal.

Yamaha dirt bike with exhaust glowing red.

Here's a bonus video of a cars exhaust glowing red.

enter image description here

  • That's a good answer. Tired of hearing from people that this is bad or whatever.....TY
    – Ppoggio
    Jan 11, 2016 at 3:30
  • Keywords: riding hard. Jan 28, 2016 at 8:23

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