I recently bought a Sick Bike Parts expansion chamber for my 70cc 2 stroke happy time. I also picked up a billet intake and high flow air filter at the same time.
I didn't really get a chance to open up the throttle until today when I had a short break from school work. The first thing that I noticed was that even after sitting for 4 months over the summer, the engine turned over immediately with the expansion chamber.
The second thing that I saw was that the engine was running fairly rich even though I had a .66 mm jet installed. Even while running rich though, the engine already allowed me to climb hills at 24-25 mph that I could only ascend at 15 mph before I got the expansion chamber!
Today, I pulled the carburetor apart and swapped out the .66 mm jet for a .64 mm jet. Suddenly, my HT was beating my 50cc Huasheng motor on my other bike. Now the little 2 stroke pulls even at 30 mph with a 40 tooth sprocket. The only main downsides to the expansion chamber are that it is fairly loud and that I cannot find a place where it doesn't rub against my rear tire or pedal.
Regardless, this product is highly recommend. I also recommend purchasing the billet intake and high flow air filter at the same time.
I didn't really get a chance to open up the throttle until today when I had a short break from school work. The first thing that I noticed was that even after sitting for 4 months over the summer, the engine turned over immediately with the expansion chamber.
The second thing that I saw was that the engine was running fairly rich even though I had a .66 mm jet installed. Even while running rich though, the engine already allowed me to climb hills at 24-25 mph that I could only ascend at 15 mph before I got the expansion chamber!
Today, I pulled the carburetor apart and swapped out the .66 mm jet for a .64 mm jet. Suddenly, my HT was beating my 50cc Huasheng motor on my other bike. Now the little 2 stroke pulls even at 30 mph with a 40 tooth sprocket. The only main downsides to the expansion chamber are that it is fairly loud and that I cannot find a place where it doesn't rub against my rear tire or pedal.
Regardless, this product is highly recommend. I also recommend purchasing the billet intake and high flow air filter at the same time.