GY6 150 Big Bore Exhaust
GY6 150 Crank 2mm+
Air and Fuel
GY6 150 Four Stroke “Stroker” Engine and the Yamaha Zuma Mineralli Two Stroke Engine seem to be the engines that I can slammed with 24/7. Which means I get more requests for these than all others. The 139QMB GY6 50 engine was at the top of my list for a long time and still is way up there. Its declined has only due to the fact of the sellers out there selling a so called 100cc big bore kit which there is NO Such Thing period.
A few years ago at Scootertronics Scooter Shop in Thurmont MD Tommy Thunder and I built several GY6 150 stroker engines. The way the math was working they were coming out to be 205cc and that was with every upgrade possible including CVT mods. Larger cylinder kits from 58.5mm – 63mm were used with heads from 61mm – 63mm. It was at this time we started simply dropping a 61mm cylinder kit in without doing any bore of cases which we were producing the cases to go along with the kits so consumers did not have to buy a bore tool. When we matched a 61mm kit with a 2mm crank, 62mm head, exhaust, 32mm carb, cold air intake, CDI and Coil that really worked good plug along with the proper cables the engine was fast very fast but did not really go much over 80 – 85 which was extremely fast for a scooter that was shaking and doing all sorts of stuff all over the road that I simply deemed it not too safe. Although it did rocket power off the line and burn rubber with a touch of the throttle. I did not want to sell parts that could cause people to hurt themselves so I backed off besides the best parts were very expensive and cost to put together correctly and not too many wanted one when they found out the cost.
Now I offer 61mm kits with heads and cam shafts which bolt on and do just about the samething and are simply easy to install and affordable. During this time and now I still find that everyone wants or thinks they need 61, 62 or 63mm kits with a stroker crank. I just have not seen where this does that much. Most who do it never get to the important parts like fuel and air, exhaust and CVT.
Also at the same time I was using 58.5mm ceramic kits and 59mm ceramic kits with 62mm heads along with the correct intakes for fuel and air and once again I got speeds of 80mph and take off that jumped right up in the air plus you have to be able to ride good. If you understand fuel and air in and air out plus the CVT the results are affordable and easy to install. This means the correct temp and velocity of the fuel and air mixture into very smooth with the right angles for ports and amount of ports into a chamber that is at the best temp that has a spark at the right time causing an explosion that rocks the piston sending force to a CVT that used every bit of this action will rip rubber at the green. So you see I know so well that size does matter due to I played in a rock band all over the US for 15 years but learned it was more about the quality of the larger size and how it was used that got the best results that lasted more than a minute.
Remember I ride what I offer and build with the parts I offer on scooters, mortorcycles (250 class) go carts up to 250 plus ride and race the two stroke scooters I offer plus have used 75 percent of the parts I offer for the last 10 years. There are Adley Moto Two Stroke scooters in stock that get 40 and above out of the box that can do 50 with a few parts. There are some 150s I will offer soon that will be upgraded when delivered plus some linhai 260s through 400s I will start delivery soon.
Along with these scooters the Thai Heist Bobber, Misfit Cafe Racer and Ace 250cc Tracker are ready for delivery and mods. BTW I will continue my shop in Southern Maryland so yes give me a call if you need repair and mods and upgrades to your scooter or motorcycle up to 250cc street or dirt for all that is needed.