When I started tuning scooter I’ve asked myself numerous times: “Which exhaust is suited for my cylinder and what size of carb should I take? I don’t want to spend money on parts that don’t work well with my setup.” Over the years I’ve gained a lot of knowledge by reading as well as trial and error. To answer the questions I came up with a list of different tuning part profiles for matching setups. Read more to find out which tuning parts match each other and what might be the perfect setup for your next project. Enjoy the best 50cc Scooter Tuning Guide on the net!
How does it work?
Below you’ll find a list of tuning parts, each divided into profiles and categories (like cylinders, exhausts, etc.). The profiles help you to check which cylinders and exhausts match and what size carburetor is suited for those combinations. When you ride a cylinder that is found in Profile 2 you should stick with a carburetor and exhaust from the exact same category. Using a part from another category can perform worse and might even damage your engine (too small carburetor, e.g.).
Please note that we are talking about stock (unmodified) tuning cylinders. Porting (modifying) a cylinder from Profile 4, might improve its performance to a Profile 5 cylinder and therefore making it suitable for Profile 5 exhausts and carburetors.
Everything below should just be used as a guideline, therefore keep in mind that other combinations might work too.
50cc Scooter Tuning Guide Profiles
Scooter Tuning Profile 1
| Cylinders | Exhausts | Carburetors |
|---|---|---|
| Original 50cc | Original | Original (12mm / 14mm) |
| Polini 50cc cast iron | Sito + | 17.5mm Dell’Orto |
| Malossi 50cc cast iron | Giannelli Nardo / Shot | |
| Hebo 50cc cast iron | Giannelli Nr-X (Minarelli) | |
| TopPerformances 50cc cast iron (Minarelli) | Giannelli Pro 6 / Pro Cee | |
| DR 50cc cast iron (Minarelli) | Giannelli Reverse | |
| Polini For Race | ||
| Polini Funky | ||
| Doppler | ||
| Yamashi S2 | ||
| Yasuni Z | ||
| Yasuni R | ||
| Leo Vince Sprinter | ||
| Leo Vince ZX | ||
| Bidalot S2 | ||
| Hebo Gara / 104 | ||
| Tecnigas Next / R | ||
| Tecnigas Basic | ||
| Kundo Kinetic | ||
| Metra Kit / Metra Kit Series II | ||
| Arrow Basic | ||
| Arrow Performer | ||
| Samba | ||
| R-Force | ||
| Stage6 Pro Replica |
Scooter Tuning Profile 2
| Cylinders | Exhausts | Carburetors |
|---|---|---|
| Polini Evolution 50cc alu | DPR (50cc spec) | 17.5mm Dell’Orto |
| Malossi MHR 50cc alu | Yasuni Carrera 20 | 19mm Dell’Orto |
| Malossi MHR Team 50cc alu | Bidalot Carrera 20 | 21mm Dell’Orto |
| Hebo Alu NG 50cc alu | Polini Evolution 50 | 24mm Mikuni |
| Stage6 50cc alu | Malossi MHR Team 50 |
Scooter Tuning Profile 3
| Cylinders | Exhausts | Carburetors |
|---|---|---|
| Polini 70cc cast iron | Polini For Race | Original (12mm / 14mm) |
| Polini 70cc Corsa cast iron | Yasuni R | 17.5mm Dell’Orto |
| Malossi Sport 70cc cast iron | Giannelli Nardo / Shot | 19mm Dell’Orto |
| Hebo 70cc cast iron | Hebo Gara / 104 | 21mm Dell’Orto |
| Airsal 70cc alu | Metra Kit Sport Production | |
| TopPerformances Trophy 70cc cast iron | Hebo 70cc Competition | |
| DR 70cc cast iron | Bidalot S2 | |
| Metra Kit 70cc cast iron | Stage6 Pro | |
| Stage6 Street Race 70cc | Tecnigas RS70 | |
| Stage6 Sport Pro 70cc | Laser X-pro |
Scooter Tuning Profile 4
| Cylinders | Exhausts | Carburetors |
|---|---|---|
| Malossi MHR Replica 70cc alu | Polini For Race | 17.5mm Dell’Orto |
| Hebo Alu NG 70cc alu | Polini Evo Cross | 19mm Dell’Orto |
| Hebo Alu / Athena / Eurocilindro 70cc alu | Polini Evo 5 / 6 / 7 / 8-serie | 21mm Dell’Orto |
| Gilardoni 70cc alu | Giannelli Nardo / Shot | 24mm Mikuni / TopPerformances |
| Polini Alu W 70cc alu (Piaggio) | Yasuni R | |
| TopPerformances Due Plus 70cc cast iron (Minarelli) | Yasuni / Bidalot Carrera 16 | |
| Athena (T-port) 70cc alu | Hebo Racing I | |
| Hebo (T-port, old type) 70cc alu | Jolly Moto | |
| Metra Kit Sport Production 70cc alu | Jolly Moto SP | |
| Airsal T6 70cc alu | Arrow Limited Series | |
| Stage6 Racing 70cc (MKII) | Stage6 R1200 | |
| TJT Racing (Piaggio) | ||
| Tecnigas RS70 |
Scooter Tuning Profile 5
| Cylinders | Exhausts | Carburetors |
|---|---|---|
| Metra Kit Pro Race | Malossi MHR Team 70 | 19mm Dell’Orto [Black Edition] |
| Metra Kit Pro Race 2 | Malossi MHR Team 2000 | 21mm Dell’Orto [Black Edition] |
| Malossi MHR 70cc | Malossi MHR Team 2004 (Piaggio) | 25mm Dell’Orto |
| Malossi MHR Team 70cc | Malossi MHR Team 2006 (Minarelli) | 26mm Dell’Orto |
| Malossi MHR Team 7T 70cc | Polini Evolution 5-serie | 28mm Dell’Orto |
| Malossi MHR Team 7T – Factory Tuned 70cc | Polini Evolution 6-serie | 24mm TopPerformances / Mikuni Flatslide |
| Malossi MHR Speed Replica 70cc (Piaggio) | Yasuni / Bidalot Carrera 16 | 28mm Keihin / Hebo |
| Malossi MHR Cross 70cc | Yasuni / Bidalot Carrera 20 | 28mm OKO / Koso |
| Polini Evolution 70cc | Yasuni / Bidalot Carrera 21 | Ibea (Kart carb, different sizes) |
| Polini Evolution 2 70cc | Yasuni / Bidalot Carrera 30 | HHC (Kart carb, different sizes) |
| Polini Evolution 3 70cc | Hebo Racing II | Tillotson (Kart carb, different sizes) |
| Polini BIG Evolution (85mm conrod) | Hebo Racing IV | Baroni (Kart carb, different sizes) |
| Hebo Manston 70cc | Metra Kit Pro Race | JHC (Kart carb, different sizes) |
| Hebo Manston 2 70cc | Metra Kit Pro Race 2 | |
| Stage6 R/T 70cc | DPR (70cc editions) | |
| TJT Racing (Minarelli) | Stage6 R1400 | |
| XSH ROOST 70cc exhaust |
Scooter Tuning Profile 6
| Cylinders | Exhausts | Carburetors |
|---|---|---|
| 2Fast4Race (78cc; 47,6mm x 44mm)* | Malossi MHR Team 2004 / 2006 (Piaggio) | 28mm Dell’Orto |
| 2Fast4Race (86cc; 50mm x 44mm) | Malossi MHR Team 2006 (Minarelli) | 28mm Keihin / Hebo |
| TCR; Team Cristofolini Racing (80cc; 47,6 x 45mm) | Malossi MHR Team Big Bore | 28mm OKO / Koso |
| TCR; Team Cristofolini Racing (90cc; 50mm x 46mm)* | Yasuni / Bidalot Carrera 21 | 30mm OKO / Koso |
| Malossi Big Bore Kit (77cc; 50mm x 39,3 / 39,2mm)* | Yasuni / Bidalot Carrera 30 | 32mm OKO / Koso |
| Malossi Big Bore Kit (86cc; 50mm x 44mm)* | JS DPR | 33mm Keihin PJ |
| Polini Big Bore Kit (83cc; 52mm x 39,2mm / 39,3mm)* | TRT 2Fast | 34mm OKO / Koso |
| Polini Big Bore Kit (93cc; 52mm x 44mm)* | Team Cristofolini | Ibea (Kart carb, different sizes) |
| XSH ROOST 77cc / 86cc | HHC (Kart carb, different sizes) | |
| Polini BIG Evolution | Tillotson (Kart carb, different sizes) | |
| Baroni (Kart carb, different sizes) | ||
| JHC (Kart carb, different sizes) |
*Bore x Stroke
What setup do you ride? Have you also created setup profiles and know which parts work well together? Let us know in the comments below or post in the forum!
Very nice listings, but HEBO and Metrakit went out of businnes. Its impossible to order these parts anymore. You shoud update it. The 28mm & 30mm OKO / KOSO carbs (PWK type) you should better replace to the new generation of PWK carbs with modified bell mouth (availble from Polini, Naraku & Stage6 brands) these are working ways better.
True that. It should however just be a rough guideline about what works together rather than giving you the perfect buying guide. Quite a few newer parts are missing in the list. You are all welcome to add them to the comments if you had good experiences with them!
are you sure that for race will work fine with 4 profiles ?
I am a little confused about the placing of the Stage 6 Racing MKII in Profile 4, mainly considering the matched exhausts. On Tuning Matters article “News: Stage6 Sport Pro MKII and Stage6 Racing MKII”
(https://www.tuningmatters.com/2012/03/16/news-stage6-sport-pro-mkii-and-stage6-racing-mkii/) it states “In combination with an R1400 or Yasuni C21 and a 24mm+ PWK you will exceed the 18hp” neither are in the comparison chart. Some websites even compare the R1400 to the C30 power curve. I am up to purchase an exhaust for my Stage 6 Racing MKII, but have no idea. This is for a new-build spare engine for balls-to-the-wall 70cc fun!
What combo ended up working for you with the Stage 6 Racing MKll ? I bought it and the Polini evo 2 after running an Airsol 70cc Alum. kit for almost 3 yrs (4500 mi.) Not sure how to tell which kit it is but ordered the t-6 R piston for it. I relied on others for all my work and have since moved. I have several projects to complete. Is there a pipe that would work well on the Polini Evo 2 and the Stage 6 MKll? I have a technigas next R I ran on airsol and loved it. Bought Laser X Pro and the evo 2 was 15-20 m.p.h less with it. Bought a Yasuni off dealer in Md. who races and sold me many parts… Not sure what model or how to identify it. Also, I have a Molossi MHR Replica kit that was not enough for the Vento R4 but I now have 3 Yamaha Jog’s.. I have lots of questions..hope you and Daniel can guide me
hi i have found that a pmtuning aluminium x-tech 70 cc big bore kit work incredibly well with the pmtuning x-tech 360 expansion champer pipe also know as the pm71rc pipe and a 21 dellorto carb
I’m riding a Polini Evo 3 with a Stage6 R1400 and 28mm stage6 pwk.
And a teamspeed 2 with a C30 and Keihin 28mm pwk both delivering more than 21hp
i have got a aprillia sr 50 i fitted a stage 6 rep exhaust, now my bike doesnt go above 10mph what do i need to do?? do i need new rollers and air filter?? thanks
You need lighter roller most likely. Is your engine reving very high or very low?
i would check everything ,,sounds like the exhaust has killed the engine to me ,,
peugeot ludix ,stage 6 airsal 70cc with up jetted standard carb and motad exhaust,,loads of power ,,hard to run in under 40 mph ,,just wants to go so fast,,i would think good for 55mph cruise all day at 45mph
What about fitting the Yasuni C16 under a 70cc Polini Corsa (Piaggio)? Atm I have a Gianelli Shot, but it just won’t work that well on that high revs as the Corsa produces, it starts to move better when the rpm’s go lower at about 60km/h. I would really like to have a slightly better acceleration than I have atm.
i recently bought a 21mm tnt carb and artek reeds for my yamaha spy it has an airsal80’s kit and a technigas powerpipe with a polini air filter when i ride to the top of my rode it bogs and dies then if i keep pulling the throttle and letting it of it sometimes stays running then dies again at full throttle any clue to what it could be i have tried changing the jet (standard jet-75-80-85-95-100) and the problem is still the same?. Help would be really appriciated
With a 21mm carb the Main jet should be about 95-105. Try the 105 and see if it still acts up. Another thing could be a clogged fuel filter. Maybe give it a try without the filter and see if it receives enough petrol!
Do you notice a difference when the choke is on? An enabled choke is kind of the same as installing a bigger mainjet. Tho, ensure that the engine is warm!
also should add of the line it wheelies and has alot of power until about 40!?
Maybe the vario rollers are a bit too light, too? Tho, the Yamaha Spy, BW’s etc have a very short transmission, so it is best to get something longer to make it more controllable!
Hi I have an airsal 70cc kit with a 21mm OKO carb… what exhaust is better for me? Yassuni R or yassuni carrera 16?
https://www.tuningmatters.com/reviews/exhausts/scooter-tuning-exhaust-test/
https://www.tuningmatters.com/reviews/exhausts/scooter-tuning-exhaust-test/
70cc exhaust shootout with the ones you’re looking at.
Also what rpms are you running up into? The stage 6 pro or pro replica i forgot which one is the one that has one of the highest hp but if you are really revving your engine out the it is the clear winner because it keeps on making power while many others fall off hard.
http://www.pedparts.co.uk/blog/sports-exhaust-testing-50cc-and-70cc-sports-mopeds-part-two
Here is a very good write up on testing many pipes and cylinders.
I’d get the C16 if you have the money and no police problems. it will allow for a better cylinder in the future too!
what pipe for the mark ll racing and a polini evo 2? will the c-21 work with both kits?
C20, C21 and R1200 are all great exhausts for these cylinders!
I AM RIDING A YAMAHA BWS FROM 1996. ..
Where would a Arrow Extreme exhaust fall into these categories?
hi
daniel
hope you can help me
i have a piaggio zip 50 t2 2013 model
it have 2300 km on the clock
i fitted a arrow exhaust to it now it go 80 kph for 1 km then slow down to 45 kph i shout of for a few minutes and go again 80 kph and start all over
this is the only modification i have don
Hi J,
That sounds like it’s overheating! It’s very dangerous! What you need to do is increase the size of the mainjet! Hope it’s not too late. Sorry for the late reply. In your case my assumption would be to increase the size by 10 numbers! Have you removed the airfilter, or something like that?
Will the C-21 work for the Stage 6 MKll Racing and Polini Evo 2 ?What type of Fuel will I need to run with these kits? 93 octane unleaded is top around here but VP race fuel and general aviation gas is available.. Use? Precautions ? How do I hide all the wires when Changing handlebars and controls. Better brakes and suspension for the Jog (’00). I have the 24mmPWK by S-6R, 21mm Del black edit. and 19mm Arrechi. Get back with me and I will get my stuff sorted and hopefully you can guide me.
Hi Paul,
That’s a lot of questions. Maybe you could write them into the Forum? It’s a better place than the comments I’m afraid!
Hi Daniel,
Great site mate!
Good information with a good range of data backing the claims too.
I notice the Technigas Triops doesn’t feature in the above list?
I’ve just paired an Alloy Malossi MHR replica 70cc with it (it was previously running with my stock 50cc setup) and was wondering which Carb. I notice the 17.5mm delorto with the polini / mhr combo. Could I expect similar compatibility with the Triops?
Cheers Mate.
Hi Dieter,
Yes, the 17.5mm is great combo with this cylinder and exhaust. The triops is a rather cheap exhaust for 50 and 70cc sport cylinders. It won’t last you forever but should work well and give you a good torque performance. 17.5mm carbs are imho some of the best choices for street riding, since they are reliable and not too crazy on the petrol usage!
Hi,
I have a quick question. I am thinking to upgrade my Peugeot Speedfight LC. I have only the Polini 70cc kit. I need all material, from exhaust to carburator. Could you help me?
I am thinking for the exhaust the Hebo, because I saw all exhaust test here in the forum. What you think?
And the carburator? 19, 21 or 24?
Thanks so much for all help.
The carb size really affects your petrol use. If you use it as a daily ride I’d go with 17.5 or 19mm max. The performance difference isnt so big. Exhaust-wise I’d prefer Yasuni or Stage6, depending on your budget. Hebo is hard to get these days. I believe they went bankrupt a few years ago?
Thanks for all the information I am new to all of this and that was a lot of good stuff thanks
Glad it helped. I wish I’d be more enthusiastic about the site and do more updates. I get more visitors than ever these days, but hardly do any updates :( Sorry for that!
Hi,
I’m riding a polini evolution 50 lc on my honda px-r.
Which dpr 50 exactly do you mean?
Are any other exhausts that work good on this cylinder?
At the moment i got a bidalot c20 and a polini cp 19 mounted.
Works pretty well but i need more power for riding in the dirt.
Greet’s from germany
Hey I just got a genuine roughhouse sport with 12 inch wheels. ordereda MHR exhaust) molassi )19 carb n 70 cast Q:can I run the exhaust without putting the new carb and piston on and add 10 to the jet? Top speed is great just need a little more take off. Thank you this is the only place I’ve found anything useful on the subject.
Hi Daniel……I bought a st6 streetrace kit with 21mm delorto carb, st6 variator kit, st6street exhaust, clutch springs for my 06 bws. I’m a daily driver jus looking for a lil extra speed(nothing crazy). Wondering if I need to install the carb or will the stock carb be suitable? I’d also like to use the stock airbox! I’d like to acheive a top speed of at least 80-85 Kph. I understand I could acheive more but I want reliability over peak performance and would like to avoid upgrading my crankshaft. Please advise:)
Hi, i have yamaha aerox with malossi mhr rep 70cc
Giannelli shot
21 carb & stock airbox with malossi filter
55% polini torquespring and stage6 red clutch spring. Problem is that it has poor acceleration to 15mph then it flys. Whats wrong
Hi, i have yamaha aerox with malossi mhr rep 70cc
Giannelli shot
21 carb & stock airbox with malossi filter
55% polini torquespring and stage6 red clutch spring. Problem is that it has poor acceleration to 15mph after that it flys. Whats wrong
Hi, i have a tgb r50x still stock. What’s the best value for money 70cc kit set up for this model? Am a daily driver so just looking for that extra power and speed. Thanks.