Recently brought a 250 EC (2005) and had my first proper outing yesterday. The use is mostly green lanes so plenty of slow light throttle use in technical areas and high speed blasts between sections.
Set up:
N1EF #2
175 main
38 pilot
Slide #7
40:1 silkolene pro 2 with 98 ron pump fuel
Elevation : 0-800m
Running:
Idle circuit just about working, but still i have to rely on a slight slide lift to idle well.
Light throttle very rich, babbabaabbaaabaaa sputtering.
Mid throttle pulls well and the exhaust note cleans up but lots of smoke
Full throttle, feels strong and revs out ok, still smokey
Cold start needs choke but can be knocked off after a very short time.
Fuel consumption seems heavy.
Due to the rich running at 0-1/8 throttle its a bit of a handful in the slow stuff, as it cleans out it suddenly comes on quite strong
Observations:
Crank seals replaced and engine sounds mechanical sweet. Reeds are good, plug is new. Exhaust stripped and rebuilt - no other issues noted.
Running conditions seem to fit with typically rich factory setting
There seems to be a huge array of needle options hidden in various posts but still I am confused as to how they compare to the N1EF (or even which std keihin needle is a close match to the N1EF). I appreciate I need a leaner straight section and probably want to progress to matching the N1EF at full throttle. Although the exhaust smoke would maybe indicate I may be able to lean out the whole needle? Thought about dropping another clip position but doubted it would solve the light throttle richnesss.
So I want to improve low speed driveabilty but I am not looking for outright power or hard hitting curve, I simply want a safe step towards a leaner needle, but what needle to try?
Appreciate any advice.....
Any UK riders that may have spare needles to sell on please pm me...
Andy
Set up:
N1EF #2
175 main
38 pilot
Slide #7
40:1 silkolene pro 2 with 98 ron pump fuel
Elevation : 0-800m
Running:
Idle circuit just about working, but still i have to rely on a slight slide lift to idle well.
Light throttle very rich, babbabaabbaaabaaa sputtering.
Mid throttle pulls well and the exhaust note cleans up but lots of smoke
Full throttle, feels strong and revs out ok, still smokey
Cold start needs choke but can be knocked off after a very short time.
Fuel consumption seems heavy.
Due to the rich running at 0-1/8 throttle its a bit of a handful in the slow stuff, as it cleans out it suddenly comes on quite strong
Observations:
Crank seals replaced and engine sounds mechanical sweet. Reeds are good, plug is new. Exhaust stripped and rebuilt - no other issues noted.
Running conditions seem to fit with typically rich factory setting
There seems to be a huge array of needle options hidden in various posts but still I am confused as to how they compare to the N1EF (or even which std keihin needle is a close match to the N1EF). I appreciate I need a leaner straight section and probably want to progress to matching the N1EF at full throttle. Although the exhaust smoke would maybe indicate I may be able to lean out the whole needle? Thought about dropping another clip position but doubted it would solve the light throttle richnesss.
So I want to improve low speed driveabilty but I am not looking for outright power or hard hitting curve, I simply want a safe step towards a leaner needle, but what needle to try?
Appreciate any advice.....
Any UK riders that may have spare needles to sell on please pm me...
Andy
