Reply To: Jetting a GT125R – 2017 ..?
If the jets are 90 and 92.5 with slide needle on rich setting, with K&N air filter (K&N 6507) and Lextek OP1 exhaust muffler and Black Widow Exhaust headers
The 125 tends to pull the best (acceleration wise) , this is also assume the mixture screws of carb did not get touched.
The Pilots can stay size 15 forever. When you remove DB Killer, bike runs leaner and screams louder but has a slower pull through gear , the only real gain is the top speed (maybe 1-5 mph extra at best)
The OEM Hyosung stock can (muffler) is very heavy and it is quite taxing for the 125cc (not really a problem for 25occ) but lightness is important to the 125cc indeed
If i use 92.5 and 95 on a customer bike, that would be maximum tube because of using NGK LASER plugs, they are a nice gold brown colour . Having a 250 cooler helps a lot too. You may be surprised how heavily used these 125s are in the UK (for work ride, for pleasure, and general riding to cities this is everyday)
Also i have advised some owners i work with in person to stop using E10 fuel, it is rubbish. Nothing positive about extra ethanol mix. So we use e5 and the bikes like it. (E0 would be ideal lol)