honestly top speed is some what important for me. but only because i am the type that likes to have that speed there, but not have to use it. just because it makes the engine run at lower rpm's and take off better. thats how i like cars too. i like fast cars, but i rarely ever go over 70. i just like to know i could, if i wanted/needed too.
My bike is a walmart cruiser. i have an sd stinger 66cc on it. it has stock NT carb. (although i am playing around with the dellorto jets). i have a k&n style air filter. i use 25:1 with Lucas semi synthetic oil. i use an NGK b6hs plug and magnecore wire (from pirate cycles). i also have a hub adaptor and 40 tooth sprocket (also from pirate cycles). i also use the teflon coated cluth cable. i was so happy after i put it on because it makes the clutch sooo easy to grip and release. very smooth! it almost feels spring loaded. i recomend EVERYONE GET ONE! its seriously like night and day. i have about 60-70 miles on the bike now. so its not even broken in yet. and i havent pushed it super hard. but with wide open throttle for about 1 1/2 city block. i can get to about 28-30 mph. i weigh 250 pounds. and i bet the bike weighs close to 45-50 pounds. so with the bike not even broken in, and pushing around 300 pounds. i would say thats pretty good without any major upgrades. i find that on my bike the perfect cruising speed is about 22mph. it feels safe, and the engine is at half throttle and an exceptable rpm.
i recently put a slant pk 80 head on and also a billet intake. i noticed the engine reved much better and when reved it will return to idle very fast. it also sounds MUCH stronger. but when i took it for a ride it didnt seem any faster. and it might actually even be a tad slower. i think i have to mess with the needle setting and jet size again. but for now my bike is out of comision because i stripped all 4 head studs in the engine. i fixed them all with heli-coils. but when putting it back together i broke the bottom piston ring. i have a new set in the mail, and i also ordered a new engine. a grubee skyhawk 66cc. so when i get that stuff i plan on having some more fun. what i really would like these engine to be able to do though, is take off from a dead stop without having to peddle. maybe with a 62 or 66 tooth sprocket you might be able to, im not sure. but i bet with those big sprockets your top speed would be like 15mph. so maybe a shift kit is the way to go. can you take off from a stop with engine only using a shift kit??
also about brakes. my bike only has a coaster brake. and it actually stops me pretty fast. especially after i bought a new rim, after my old walmart rim died on me. the bearing keepers all ripped apart. so i bought a new rear rim from a bike shop for $54 and put it on. it has a shimano brake, or maybe the whole rim is shimano..? im not sure how that all goes. but let me tell you! with that new rim and brake on there the first time i went to slow down i almost crashed. because i didnt expect the brake to stop me THAT fast. i have no fear what so ever with just a coaster brake. especially the one i have on there now. although i suppose a front brake would be a good idea. i dont think its neccesary...
CAUTION! one last word. to anyone who is new to this, as i was. be very careful when tightening EVERYTHING on these kits. everything on the kit is very cheap and you will strip it without even trying. i have stripped out almost every hole, bolt and stud on this kit. thankfully i have been able to fix what i have messed up. heli-coils are a god send! jb weld... not so much. i first tried to jb weld the holes, but they pulled right out. so i would say just go straight for the heli-coil! it works great if you are careful drilling the holes. basically the rule is. stop tightening way before you think you should. and just use lock tite to make sure it stays put. also dont use a 3/8 ratchet for anything. 1/4 will do just fine! it would also be a good idea to just replace the hardware with decent quality stuff from the get go. but if not, plan on having to do it later...
