jet size

[nc30 madness]

hey guys

what size jets would i use if have an ethos exhaust system
just found out my bike is running too lean

[CMSMJ1]

How did you find out?

If it was on a dyno...why did the operator not tell you?

What is it running now?

What makes you think it is lean (if it was not on a dyno?)

basically....this is a piece of string....how long is it?

[nc30 madness]

i took my bike to a mechanic, he told me
my bike had a standard exhaust but i changed it to an ethos system, my carbs still have the original jets in them, my mechanic said that this is prob causing the over heating. my bike is also cutting out very easily and does not want to iddle, i pulled the choke out a little and the bike iddles perfectly

[Cammo]

i took my bike to a mechanic, he told me
my bike had a standard exhaust but i changed it to an ethos system, my carbs still have the original jets in them, my mechanic said that this is prob causing the over heating. my bike is also cutting out very easily and does not want to iddle, i pulled the choke out a little and the bike iddles perfectly

None of that is a sign that it needs main jets changed. If I was a mechanic getting paid on an hourly rate I would tell you that also...

When does it overheat? long periods of idling or normal road riding? If it overheats during normal riding then the cooling system is suspect. Overheating at idle could be a poor cooling system, or the pilot screws running very lean. On these bikes it's usually because the rads need a good clean, or it could be something more severe.

Adjusting the pilot screws could help with the idling problem (adjust them to 2.25 turns out which will suit your exhaust system). These do need adjusting usually when the exhaust is changed from standard. You can adjust them with the carbs on the bike but you'll need right-angled screwdrivers and a lot of patience.

It's easiest to adjust them with the carbs removed. While you have them off you may as well rejet them yourself (118 front, 120 rear will be the right size if all of your induction/filter setup is standard). Get into it!