The exhaust makes a huge impact on 2T performance more so than on a 4T . When mine was stock it would hit 50 on the speedo but mostly top at 45 . A larger main jet often helps . I bought the blue racing CDI which helped on takeoff but had the same top end as it topped at 8,000 RPMs . I tried going from 6 gram rollers to 4 grams and it over reved and lost top end so I mixed them up to equal 5 grams . A NGK BRP8HIX irdium sparkplug really helps it run at its best . The 90cc crate engines are pretty much gone as they are longer imported . You can get a 2T power kit which has a BBK , exhaust , clutch , variator , carb and intake like this one
eshop.mainelyscooters.com/performance-parts/performance-kit/169-210I put on a 47mm BBK from Modcycles along with a MMG pipe and upjetted the carb . Wow it was so much faster and could hit 10,500 RPMs as the exhaust port was fully round on th BBK where the 49cc it was D shaped with more material but could be ported some . I can pop a wheelie at 50 MPH and it goes to where it would be 70 on the speedo as I have not GPSed it . The 5 grams was ok for th e50 but too light on top end with a BBK and I now have 8 gram Dr Pulley sliders along with 1.5k clutch and torque springs and the with this part too to prevent the torque spring from binding
eshop.mainelyscooters.com/by-brand/hoca/169-281Many Minarellis come with a 17.5 mm carb and the Powerkits often have a 21mm carb . I was lucky my scooter came with a 19mm TK carb which is made in Japan ( better than a China carb ) which is easy to tune as it is not sealed and the idle screw is knurled so I can adjust it with my fingers or a screwdriver . I have read where some tried larger than 21mm but it was a pain to tune and did not perform well . You can get a carb like mine for only 50 bucks where as a premium brand can be over 125 and up depending on brand and size . Replacing the intake with a larger throat and Fg or CF reeds should help . If you have deep pockets then look at
www.ecotrons.com for their EFI kit where the 2T has option to have a secondary injector .
Before you buy parts make sure its a horizontal Minarelli and not a Morini engine . The come in 10mm and 12mm wrist pins sizes too . This is from Scrappydogscooters will help you figure it out as well as measuring the wristpin with a caliper MINARELLI 2STROKE PISTON PIN SIZE DIFFERENCE , 10MM vs 12MM
and variator size difference
Hey MO! How the heck do I know if my Minarelli based engine has a 12mm or 10mm wrist pin, without taking it all apart first? - Confused in Chicago
Our knowledge database is growing, but we know a few things. Adly's and Hammerheads are 10, so are the Italian Minarelli engines like Malaguti, Italjet, Beta, and Aprillia. The 12mm pin is found on later CDI's, chinese JOG-2T, Vento Triton. These engines are poplular in 2-stroke full size scooters and ATVs such as Malaguti, Yamati, United Motors X-Speed, Aprilla, CPI, Benelli, Vento, Eton, Adly and many more. Italian made units tend to use 10mm pins (Chinese JOG 2T clones tend to use 12mm) please measure and check before ordering. Certain brands such as CPI / United Motors / Muz older models used 10mm newer post 2004 use 12mm. All Italian made models use the 10mm such as Aprilia / Malaguti / Italjet that are Yamaha Minarelli based.
Probably the most accurate, without complete disassembly, is to measure the inside diameter of your variator pulley. If it is 21mm, your wrist pin is 12mm. If it is 18mm, your wrist pin is 10mm. You can also count the number of splines on the outer variator face where it mates with the crank. The smaller 18/10mm crank has 17 splines, the larger 21/12mm crank has 15. The larger crank was originally designed for the JOG90 engine, but comes in 50cc too. Also, don't confuse your Minarelli 2stroke with the Franco Morini type two stroke found in TGB R5 Laser, Key West, 101S, the Suzuki Address, and some Italjets. These kits are also available from Scrappydogs, as they are authorized dealers for TGB products.
Hope this helps. MO!
Here are our Minarelli based parts link. Minarelli Here is link to HP parts
www.scrappydogscooters.com/50cc_2stroke_Performance.htmlMost go with iron block since its cheaper and more forgiving in a soft seize than aluminum is . The dual ring is for street use and will outlast a single ring piston . The single ring can rev higher with a tuned exhaust but since its a daily driver go with dual ring . I have this kit
shop.jupiterscooters.net/Cylinder-kit-75cc-Minarelli-10mm-wrist-pin-Made-in-Taiwan-MGMP0108-75CC-10mmpin.htm and it is much easier to install a BBK on a 2T as it only took me a lil over and hour to install as my scooter has a handsome boy body and I only removed the body panel which came off as a single piece rather than drop the engine from the frame .
My stock oil pump failed on me twice so I now have a Mikuni oil pump with a new throttle cable part # 159-26 from PFS as the stock cable would not work .
The 2T oil you use plays a big factor on how it performs too . NEVER use weedeater oil as you can get synthetic blend like Lucas for 7 a quart or Motul 710 which is full synthetic for 17 a quart . Cheap oil smokes more and fouls out the sparkplug . Mine only smokes at startup with only a lil bit once warmed . When I had pedal mopeds I premixed at 32to1 I would leave a com trail of smoke as being 13 I had a limited budget from cutting grass around the block . Premix is a safer option but a hassle compared to using an oil injector .
With BBK your MPG will be less but well worth the tradeoff with more power and speed . I can go uphill faster than many small scooters can going downhill . I raced a 150 and we went back and forth from takeoff as mine is not fast one off the line like Hondas are but in the end I passed by him as he yelled " Nooooo " and I smiled .
I installed a Uni vent cover which is much smaller than the Uni airfilter and I went from a 75 to a
mainjet while still being 49cc and wow it had better takeoff and midrange but same top end . Tried the big red Uni with the
MJ and dang it softseized on me going around the block where I had a few hundred miles on the vent cover as an airfilter with no issues .
Plan on doing lots of research first , have a notepad to write down how it is now in order to compare it later with each mod . If you do it all at once and have a problem it takes longer to troubleshoot that a single mod at a time and test it out . Jetting on a 2t is very picky you get a few main jets or a jet kit after finding out what size your carb uses . Mine and many others use Mikuni VM11/22 main jet I bought from
www.powerbarn.com . I also had a 40 idle jet and now have a 45 IJ/
Most use the term LC for liquid cooled rather than WC
im looking to get more top speed and acceleration on a budget of hopefully no more than $600, and my question is what upgrades should I do first? My scooter is a bone stock Rocketa MCR-15-50 which I believe has the minarelli 1E40QMB 2t engine. I look forward to everyone's input, thanks! 
bbk you are gonna
