NC21 Wont start after 1 year of staying

[Neosophist]

So i found the plug, but one of the pins in the plug was oxidized / scorched and certainly isnt making contact.
Anyway how should i measure the AC voltage when i disconnect the plug. Sorry i am not really into electricity.

you have at least 2 problems here.

carbs appear to be leaking air.. most likely carb rubbers / carbs not fitting in proeprly.

maybe electrical system.

can you post up a picture of your multimeter?

[demerdzhiev]

So the electrical problem is gone now when i fixed that burnt cabel. Havent checked if the battery is being drained but the multimeter is showing normal index. Haven driven it since its working very strange. I think its running too rich. The exhaust smokes a lot, and the throttle respond is realy bad. When i leave it on idle and then rev it after 5k rpm it happened to make w boom in the exhaust, feels like one of the cylinders had just woke up from a long sleep hahah

[Neosophist]

So the electrical problem is gone now when i fixed that burnt cabel. Havent checked if the battery is being drained but the multimeter is showing normal index. Haven driven it since its working very strange. I think its running too rich. The exhaust smokes a lot, and the throttle respond is realy bad. When i leave it on idle and then rev it after 5k rpm it happened to make w boom in the exhaust, feels like one of the cylinders had just woke up from a long sleep hahah

maybe your float valve is sticking or your float is lekaing fuel into carb.

[demerdzhiev]

The float isnt leaking fuel but mixture too rich, cant fire the engine even without choke, when i pull out the plug its wet as f*ck. pilot screws 2 turns out ....

*question - how the pilot screws affect the mixture: winding them out leans it or winding the in leans it ?

[demerdzhiev]

When i stopped the fuel supply to the carbs and drained them by very little, the engine started so i guess that leads me to float height problem, but last week when i got them off i adjusted it.... 6.8mm right? while the needle's spring isnt pushed?

[Neosophist]

The float isnt leaking fuel but mixture too rich, cant fire the engine even without choke, when i pull out the plug its wet as f*ck. pilot screws 2 turns out ....

*question - how the pilot screws affect the mixture: winding them out leans it or winding the in leans it ?

pilot screw is very fine adjustmanet for idling mixture.

2 turns will be fine, if you have to put it somewhere else then you have different problem.

if the plugs are wet the floats are set wrong or they are leaking / sticking.

[demerdzhiev]

I think the problem is with the float heigh. I first set them at 7 mm (~6.8) (Valves not leaking/sticking. Checked if there is fuel in the bowls. I am using an alternative fuel supply and the hose between the tank and the carbs is transparent and i can see the fuel level when the tank is empty and the fuel is only up to the hose that the valves dont leak) but the strange thing is that at that height one of the cylinders didnt even worked (wet plug => very rich mixture), the bike starts without choke on (temperature outside was about 5 degrees Celsius. with choke on it didnt start. cant rev over 5k rpm. After 10-15 min of working the engine revved up to 6-7 k rpm

Today put the float height at ~10mm. the choke started to make a difference but still fires without choke on when cold and still cant rev??

[Neosophist]

I think the problem is with the float heigh. I first set them at 7 mm (~6.8) (Valves not leaking/sticking. Checked if there is fuel in the bowls. I am using an alternative fuel supply and the hose between the tank and the carbs is transparent and i can see the fuel level when the tank is empty and the fuel is only up to the hose that the valves dont leak) but the strange thing is that at that height one of the cylinders didnt even worked (wet plug => very rich mixture), the bike starts without choke on (temperature outside was about 5 degrees Celsius. with choke on it didnt start. cant rev over 5k rpm. After 10-15 min of working the engine revved up to 6-7 k rpm

Today put the float height at ~10mm. the choke started to make a difference but still fires without choke on when cold and still cant rev??

do NOT set the float heights to 10mm.. that is not fixing the problem, if it makes any change then it is only compensation for origianl problem.

float heights need to be 6.8mm.. at severe altitudes 1mm plus or minus is all you really need to adjust.

do you know how to test the fuel?

with the carbs at the right setting.. 6.8mm.. put them on bike

fill your clear tube with gasoline and mark the line.. leave the biek for 1 hour.. if the fuel has gone down then it is leaking gasloline from the flaot into the engien.

[demerdzhiev]

So for one whole day staying the fuel dropped few inches, but i am not sure that on working engine it can make such a difference on the work of the engine (i mean to rich the mixture that much)

[demerdzhiev]

How can i check for what model my carburetors are, the serial number is on the linnk between the carbs on the both left/right side right?