Besides the intake rubbers, pilot jets and butterfly pivots what are the possible air leak locations on an nc30? I'm trying to cure hanging revs and a rough idle.

krisztian_andre wrote:Besides the intake rubbers, pilot jets and butterfly pivots what are the possible air leak locations on an nc30? I'm trying to cure hanging revs and a rough idle.

Hanging revs is a lean mixture often caused by air-leak but are your floats set right and mixture screws all correct?

Next is the carb balance screws, theres 3 and the take-off for the vaccum tap.. these can all leak air.

The throttle butterfly balance screws? They don't look like they penetrate the carbs at all. Floats are set to 6.8mm and pilot screws to 2.25 out and the bike is standard. What was that test for the carb rubbers, spray wd40 on them and see if the revs change?

hanging revs could be a air leak anywhere, not just on carbs. norm a sign of lean like said.

Neosophist wrote:

krisztian_andre wrote:Besides the intake rubbers, pilot jets and butterfly pivots what are the possible air leak locations on an nc30? I'm trying to cure hanging revs and a rough idle.

Hanging revs is a lean mixture often caused by air-leak but are your floats set right and mixture screws all correct?

Next is the carb balance screws, theres 3 and the take-off for the vaccum tap.. these can all leak air.

No the air-take off screws for balancing the carbs they are sealed with an aluimin crush washer and penetrate the cylinder head.

There are 4 but the one is used as a take-off for the vaccum tap, so theres only 3 screws but 4 places.

What does experience say about those crush washers, would you replace them? Fiche says they are 5mm but nothing else.

Have you balanced the carbs lately? Hanging revs is normally pilot screw setting out of adjustment.

Air leaks at the carb rubbers are common, I doubt air is getting past the balance take off screws.

I have serious electrical issue at the same time where the engine randomly cuts out along with electrical power and my voltage at the battery decreases with the revs increasing. I will sort that out first because it's probably related to the rough idle.

krisztian_andre wrote:I have serious electrical issue at the same time where the engine randomly cuts out along with electrical power and my voltage at the battery decreases with the revs increasing. I will sort that out first because it's probably related to the rough idle.

your generator is fucked then - get a look at it - it is not providing enough load to keep the battery charged when the bike it needing the power to keep them sparkies rolling at the higher revs.

CMSMJ1 wrote:

krisztian_andre wrote:I have serious electrical issue at the same time where the engine randomly cuts out along with electrical power and my voltage at the battery decreases with the revs increasing. I will sort that out first because it's probably related to the rough idle.

your generator is fucked then - get a look at it - it is not providing enough load to keep the battery charged when the bike it needing the power to keep them sparkies rolling at the higher revs.

Crush washers dont usually leak, I should clarify that if they are missing or the vaccum hose is split then thats likely.

Since youve mentioned your electrical system is haywire then this is the most likely cause