Hi people, I'm new here and have been slowly upgrading my bike, Its a 50cc 2 stroke, Chinese made. Its has lots of work(no mods) and is an old bike, 30000 km, I've recently upgraded the exhaust to a "sports" one, it has made a massive difference to power along with a cone air filter, brand new carb(replica 12mm) I've upjetted from stock 75j-84j but think I'm running lean on my main jet anyway that's another thing, Im writing this because when I accelerate it's slow and so is uphill eventually on flat ground it picks up at a consistent speed and keeps climbing Rpms, it's great fun downhill too (70mph), until I stop at lights or see a slight incline in my view, the speed drops dramatically by 10-30mph, If I don't have a run up the speed will drop to 15mph and might not even get up a steep hill, taking this as being my rollers but I'm confused, when I didn't have any mods I got a mechanic to sort my bike out he told me he'd upjetted, changed rollers and cut CAT out of old exhuast, the rollers however was 4.5g would this not already be light enough ? The lowest I can get is 2.8g but wouldn't that be way to light ? I'm confused to why it's like this even with light rollers in (4.5g) I've thought about the torque/contra spring and clutch springs will this make any difference ?
