Maximizing the potential of a 66cc bore

[fujio001]

I have a Sym DD50 with a 66cc bore kit, Keli variator, upjetted, V8 exhaust(probably too bigfor my kit) and stock carb.

I can get to about 50 mph but it takes some efforts for the last 10mph.

Would there be a benefit in the top end by switching to a lightly larger carb like a 17mm or 19mm?

With a little more power maybe I can benefit from some different gearing.

Thanks in advance.

[fujio001]

Just an update on my Sym DD50. The V8 was just too big for the 66cc. The shop I am working with traded it with a YMS28 and immediately the response was greatly improved. I also changed the variator weights to 6.5 gram Dr. Pulley sliders and the center spring is a red 1k. Clutch springs are 1.5k and it is working great in traffic and when holding a constant speed. The Dr. Pulley sliders give me more pick up and a higher top speed. With stock gearing I easily hit 50mph and comfortably cruise at 45mph. Unfortunately I do not have a tach so I do not know what RPMs I am running at. Just a side note, The sliders work well with a Keli variator and stock ramp but not very well with a more aggressive Daytona ramp. I am not sure why however the engine revs at higher RPMs with very little difference in performance.

Now that I am feeling more confident, I am thinking about adding a slightly larger carb. Maybe 17.5 or 19mm. After that, maybe a mild port and polish - especially the exhaust.

It is pretty amazing how much of a difference the right parts can make in performance and the overall riding experience.