just bought o.s plugs # 8 and a new temp gun

good. now did you determine if the first fuel was castor based? if it was do not use the blue thunder,try to use the same fuel again.if it was not castor based great put your needles back to the factory settings refer to the ns25 owners manual for the correct settings.now on my savage i had to watch the bottom needle because it had no shoulder to stop the needle so it felt like it took forever to bottom out or "close".once you have the settings redone make small adjustments one hour at a time to retune it.
good luck
steven

it was backyard basher 2o% nitro 16 % oil was the old fuel i was useing
but now useing blue thunder don't know if it had castor

heres the old fuel it dose have castor

http://www2.towerhobbies.com/cgi-bin...?&I=LXBBS7&P=7

well i can tell you for sure that you wil either have to go back to the other fuel or switch to another castor based fuel.the synthetic fuels can not clear out the castor but the castor will clear out the synthetic the two are fight ing each other in the engine thats whats causing it to run hot.switch fuel or tear the motor apart and clean all the castor out with denatured alcohol then reassemble and retune.
steven

can i first use up this blue thunder i don't want to wast money

yes you can but first you have to disassemble the motor and clean out all the left over castor inside then you can run the blue thunder.but if you dont the castor and the synthetic will fight each other and it will run hot.

as soon as i use up this bottle of blue thunder i am swicthing