Iggy tests Scorpion’s British-made, lifetime warranty GTS exhaust for 6,000 miles. If you’d like one you can buy one from our SLUK Shop with free postage

Here’s Iggy’s verdict…



Aftermarket scooter exhausts are a funny old game. We’ll think nothing of taking a perfectly useable standard system off a new (or old) scooter and replacing it with one that sounds a bit noisier and looks a bit nicer. We’ll pay the best part of £400 for the privilege as well.



Why fit an aftermarket pipe?


There are some positives to come out of fitting an aftermarket Vespa GTS exhaust. For starters it gets rid of that troublesome standard exhaust gasket, that’s £20 saved every time you take the exhaust off and a bit of peace of mind that it won’t blow out halfway to a rally.


Secondly the Scorpion system is made from stainless steel so won’t rust. It also sounds so much better than the standard exhaust and you have the option of removing the DB killer if you want to make it a bit louder. With the decibel killer in the exhaust is road legal, without it you’re more likely to make a nuisance of yourself.   


Thirdly you’ll save weight, standard exhausts are heavy. Fitting the Scorpion will save you 1.5kg’s compared to the 5.6kg standard OEM exhaust. 


Finally this Scorpion does increases power from 17.6bhp to a claimed 18.4bhp – a small but worthwhile gain of .8hp (on the Dyno we actually got .9bhp).


Lifetime warranty


One final big selling point for the Scorpion is it’s lifetime warranty. The factory is based in Derbyshire; which makes any future problems much easier to sort out if you live in the UK. In my experience they have always been very helpful. If you get a problem with the exhaust send it back to either them or your local Scorpion dealer and they’ll sort it. Good aftermarket sales are worth a few quid in their own right. 


Exhaust sticker slightly singed in Spain
Exhaust sticker slightly singed in Spain

It’s fair to say my Vespa GTS 300 has been used and abused so far in its 18-month lifetime, as such it’s the perfect test bed for parts that need a good thrashing to test them properly. Like this black Scorpion Serket exhaust system for instance. 


6,000 miles so far


I’ve been using this exhaust since the end of 2015 and it’s covered around 6,000 miles so far, most of those miles have been done heavily loaded and two up. It took me and my pillion for a fortnights holiday, touring the South of France and Spain. The scooter is ridden flat out as often as possible and if ever an exhaust was going to be subjected to extreme heat cycles it would be this one. Perfect for testing out the longevity of the Serket exhaust design, fittings, internals and of course the ceramic coating that gives it that stylish colour (it is also available in brushed stainless). 


The complete system as it comes (brushed stainless shown)
The complete system as it comes (brushed stainless shown)


Fitting notes


The exhaust comes as a complete system with all the bolts, fittings, springs and an instruction sheet. The only part that needs assembling prior to fitting is the hanger bracket, that just bolts to the rear of the silencer and is on a slotted mount so it can be slid into place perfectly.


  • When removing your old exhaust it’s easier if you disconnect the lambda sensor rather than unscrewing it in-situ. If you leave it connected the wiring can get tangled as you undo it and damage the wires. 


  • Also when fitting leave all the bolts loose until the system is in place, then tighten up from manifold to exhaust hanger.


  • It’s good practice to copper grease all bolts as you fit them, it’ll save hassle the next time you try to remove it after a dosing of road salt.


6,000 miles on


As I said earlier, this exhaust has had some serious hammer this year but what do I think of it? Firstly it goes on really easily, there’s no need to pull it about to get it to line up, the fit is spot on. An exhaust that fits well, is supported well and isn’t too heavy is always a good thing. This weighs 1.5kg less than the standard system and because it fits well the exhaust isn’t under constant strain so it shouldn’t be prone to cracking. 


Over the years I’ve tried various exhausts for the GTS, I’ve had every variation of the Scorpion, an Akraprovic, Remus, Remus Dual, PM and a ceramic coated standard. The GTS runs very hot and no matter what finish or colour of exhaust all of them have discoloured to a certain degree.


Getting a black coated exhaust to work without discolouration on a Vespa GTS isn’t as straightforward as it sounds, a GTS puts out more heat than a race bike. In fact in early trials for this exhaust the composite end caps were prone to melting due to a build up of heat in the relatively short can. These are the exact same end caps as superbike race teams use on their Scorpion exhausts in BSB. The original black coating they used was also causing problems on the scooter so a rethink was in order. 


The new ceramic finish and revised exhaust outlet put production of the hand built exhausts back until the end of summer, meanwhile I was blasting around trying to break this prototype Serket exhaust. I failed, thankfully for the factory. Although the can is showing some slight discolouration and the sticker has melted away it has been otherwise faultless. Plans are afoot at the factory to cure both of those issues so we’ll keep you posted. 



.9bhp increase isn't bad at all
.9bhp increase isn’t bad at all


Sound: The sound is one thing that draws us to choosing an exhaust, this one sounds very pleasant, even my other half commented on it when she was on the back (she’s done almost as many miles as me on it). It’s not too loud with the DB killer in and even with it out it’s not as offensive as some other exhausts I’ve used. 


Two up clearance 


Although neither of us are too heavy you can see we make up for it with our luggage. 17 days touring, complete with kitchen sink and there were no issues on ground clearance or melting of the rear lower side panel. That’s on standard shocks as well. 


Spitting flames: As you can see from our video the exhaust is prone to popping on the overrun as you come off the throttle. The video shows it without the DB killer and unburnt fuel ignites as it leaves the silencer. On the road this is one of those things that some people find annoying, others quite like. Personally I like it but I usually ride with the DB killer in and it’s nowhere near as prone to popping in road legal guise. If you do like to light up those darker nights though you can make it spit flames at will by backing off the throttle then opening it again momentarily just before it’s ready to pop, car drivers love this kind of thing down a dark lane and it can keep the rider entertained too. 


Power: We all know there aren’t quite the same gains to be had from a four stroke exhaust as their are from a two stroke expansion pipe but even without a dyno mine felt instantly quicker on acceleration. A noticeable difference over standard. Unlike some exhausts I’ve tried in the past (an early Scorpion for one) it doesn’t lose any top end speed or power either. This feeling is backed up by the dyno, with a 0.9bhp power increase on a brand new GTS without the DB killer, extra power without a trade off is always a good thing to have. 


Price: Stainless steel £349, black £399


This is how it looked after 17 days touring Europe and 2500 miles on the road
This is how it looked after 17 days touring Europe and 2500 miles on the road
After a clean up it didn't look bad at all, just a bit of heat discolouration.
After a clean up it didn’t look bad at all, just a bit of heat discolouration.




The photo above shows the scooter just after returning from our trip to Spain & France. The heat resistant sticker surrendered itself. This is one area the exhaust fails on, it looks messy without it but they’ll replace it for free. The factory will be laser etching the Scorpion logo on though before long so that won’t be an issue. The link pipe has also blued due to the heat.  




Once washed the can looks good enough, aside from sticker residue but the main thing is it still sounds as good as it did when new. It’s not broken, disintegrated internally or caused me any other issues. Power still feels as good as it did when first fitted and I’m getting a good top speed. Acceleration is impressive as well. 


Lab report


The Scorpion Serket exhaust looks great, produces slightly more power than standard, comes with a lifetime guarantee and is made in the UK. What’s not to like? Ok the sticker melting issue is a slight problem, the reason being that the sticker itself is aluminium backed so produces an added heat spot on an already hot can. The laser etching process will sort that issue out though soon (update Jan 2018, all Scorpion cans now come laser etched).


We’ll also be testing out a revised exhaust for them, it is said to reduce heat build up by 40% and the can is slightly quieter. We’ll be checking those claims out using thermal imaging cameras and a good thrashing in 2017. 


Words, photos and video: Iggy


Lab rating: 9

Buy one from the SLUK Shop

Buy one from the SLUK Shop

The Scorpion exhaust is the latest product to be added to our SLUK Shop. We’ve got an exclusive free postage deal on the exhaust. Simply click on the link to go through to the shop page and buy one now in either black or stainless: Scorpion SLUK offer