Want more speed out of honda spirit

TAKE AIR FILTER OFF AND CHECK IT OUT. OIL MAY HAVE COATED THE FILTER.

Some bikes will have this problem no matter what age or condition. I was taught years ago to slow down and stop in second and downshift to neutral whilst slipping the clutch. First gear on bikes is pretty low in ratio and to match speed of engine with road speed is very difficult at times, so suggest using second. Try it.

Hello there ... Well you got me confused ... What exactly do you mean by saying back firing ? If you hear some noises from the exhaust and seeing flames now and then you must first check your carburetor . There might be something inside blocking the way , then you must look at the carburators neck ... Check for cuts or possible air loss same with the air pump... After that you can check the exhausts for any possible holes on the front neck or somewhere after the neck ...is the sound of the bike any different ? Check the chain also you could need some tighten if that's the back firing you mean ... I hope I helped !!!!

it could also be air filter. check your throttle cable for kinks or need to adjust .

Change pipes (open once), change jets (slow -5 up and main -10 up), custom air filter. If you do 1 or all of it, at the end you have to sync the carbs, and you must know, your bike will operate at higher temperature, so, do not overdo, if you want to have a bike for some time.

It's only governed by the sprockets. I had a familiar problem. I rebuilt the carbs and had to bypass the fuel relay. Also if itbackfires need to adjust and replace exhaust donuts

could be several things
1-- coolant radiator is partially blocked or the thermostat is not fully opening reducing the flow of coolant through the radiator
2--- tuning is too lean at full load which causes overheat conditions for the engine
3--- timing a bit retarded for the rpms
i t is all connected to the extra load from the head winds requiring extra throttle that you would not normally use in normal conditions
another place to check is the fairing in use as the extra wind speed from the bike and the head wind may be causing a turbulence around the radiator and so preventing full air flow to the radiator

buddy dont worry about it what you have done is put to much oil inside the engine and as the piston goes down it cause abit off pressure which in the small space it has when you over filled it the pressure inside has just forced the oil out the breather into the air box just give it a little clean and drop oil aswell bud

please close my account with you, not what I expected nor do I think you can help me without the $ thing. Some forum this is..