premix???

[psychoskoots]

just curious if the stock oil pump isnt putting out enough oil? i have a 70cc BBK, 17.5 carb with a 95 jet and a k&n air filter,  a tecnigas next r pipe and switched my oil to royal purples fully synthetic. doesnt seem to run right and when im riding it feels like the piston is seizing up and it dies on me after a weird whining noise and loss of power. i dont really want to ride anymore and was wondering if i should start premixing and if so what would be a good ratio?

[harry]

50:1

the wrong plug will seize you up just as fast as no oil..

oilyhans

[psychoskoots]

the spark plug? i was using the same one that it came with. how would the plug do that? didnt start acting this way until i put the carb and exhaust on.

[harry]

simple , the stock plug runs at a certain temp range.
thats what the number on the plug means
when you put on a bbk  the scooter will run hotter and over the
safe operating temp (so you normally go with a cooler plug)

now you might be  lean(also causes  heat) with the carb and new exhaust
 add the 'too hot plug' condition and your ready to seize the motor
 with the first short ride you take.

 it happens all the time with people that don't research how to really do a
bbk swap correctly .

 oilyhans

[psychoskoots]

makes sense... the plug that was in it stock was a NGK BPR7HS heat index of 7 and the one i have in there is a autolite 4123 heat index of 3 so i am running a cooler plug...do you think the jetting might be off due to the bigger carb and air filter? is a 95 not big enough? stock was a 60 but on a smaller carb...

[harry]

you should find out what 'heat index of 3'  means  is 3 300C?
optimum temp is about 450C <842f>  to 550C <1022f>
i don't use autolite plugs all i know is that  the lower the number the cooler
the plug.
as for the ngk plugs the bigger the number the cooler the plug.

when you have a really big jet in a small carb the fuel is more big droplets
than atomized fuel vapor.
just for comparisons the stock jet in a 17mm carb is a 85....

also i don't recommend open filters due to having to tune and re tune due
to weather changes like hot summer and cool spring & fall.

oilyhans