Carb intake sealed, still no idle.

jon31592 · May 1, 2011

New motor, 66cc sky hawk with NT carb. Recently got it started. Runs alright at WOT but jerky bottom end. Plus I have no idle... I could be riding and pull in the clutch and after the engines RPMs go down it cuts off... I was thinking an air leak... I tried the screw in every position, sealed between the carb and the intake and around the gasket also. Same issue.

Where else might air come from? I thought an air leak was my problem but now not so sure.

Iv looked around the threads and searched and can't find an answer to my issues... (then again, sometimes I can't find my phone while on it)

This thing is really testing my brain...

I really did not want to ask such a noobish question like this but hey, sh!+ happens...

If it's not idling then it must not be getting enough or too much of something right? I know fuel flows through the line, I sealed what I could..

I know that there is a needle connected to the throttle that has an effect on things and that is on the middle notch. And I removed the jet and could see straight through it.. Idk what the issue is...

It's prolly really simple too.....

The 26incher · May 1, 2011

Make sure you are not getting an exhaust leak too...

GearNut · May 1, 2011

A weak ignition can do that as well. Check your wiring, try a better spark plug such as an NGK BP7HS and definitely get rid of that lousy factory spark plug wire and spark plug cap.
At least try a different spark plug, next to cutting off the lame factory wire connectors and soldering the connections together (which is HIGHLY recommended, do a search on it...), a spark plug is the next cheapest thing.

Last thing to come to mind is leaking crank seals or leaking crank case gasket......

Al.Fisherman · May 1, 2011

Sounds like a intake leak somewhere. Double check for proper piston alignment in the carb . The long cutout where the cable inserts aligns up with a alignment pin in the throat of the carb. The wedge cutout aligns with the idle screw.

DuctTapedGoat · May 2, 2011

On your throttle slide, I'd add a notch and go from there. Though, I as well support what has been said, leaning strongly to sparkplug and electrical/wiring.

jon31592 · May 2, 2011

I don't know where my crank seals are located at... isn't there one by the magneto somewhere?

Im pretty sure Im running rich also because my spark is like... black and oil laden... After this tank Im going to go to a 50:1 ratio and see what happens... or I could just add some gas to whats in my tank... (about a third of a gallon)

Sometimes on my WOT it picks up power and sounds less rough. Is this just the motor breaking in or could that be because of the rich gas mixed with a possible air leak?

jon31592 · May 2, 2011

Okay, to clarify you ment that I should move that c clip to a lower notch on the needle therefore raising the needle while in the carb correct? I just did that and it did seem to purr instead of put put on WOT but still no idle action.

So, back to the oil gas ratio thing, I should just keep giving it what im giving it or give it more oil because Im about 24:1ish now since its a new engine...

jon31592 · May 2, 2011

Okay, I lied... I get idle with the screw all the way in... but, not always... and if I idle and lift the rear wheel it spins.. if the clutch is not engaged this shouldn't happen correct?

DuctTapedGoat · May 2, 2011

jon31592 said:
Okay, I lied... I get idle with the screw all the way in... but, not always... and if I idle and lift the rear wheel it spins.. if the clutch is not engaged this shouldn't happen correct?

If your motor is pulling your wheel with a disengaged clutch, you need to adjust your clutch. This would mean when you're stopped holding the clutch in your motor is trying to accelerate, but you're keeping it from going and it dies.

1. Make sure the clutch's cam is perfectly flat against the pin.

2. Put the clutch in the locked position.

3. Open the crankcase side and adjust the flower nut to raise the clutch plate. Just a notch or two, then roll it around (because your clutch is locked) and feel for resistance.

4. When you think you have it good, fire it up and lift your back wheel with the clutch in the locked position. When it doesn't move, you've got it set to where you need it.

GearNut · May 2, 2011

jon31592 said:
Okay, to clarify you ment that I should move that c clip to a lower notch on the needle therefore raising the needle while in the carb correct? I just did that and it did seem to purr instead of put put on WOT but still no idle action.

So, back to the oil gas ratio thing, I should just keep giving it what im giving it or give it more oil because Im about 24:1ish now since its a new engine...

You have the right idea, but you executed it backwards.
You are all ready too rich and lowering the clip position to raise the needle will add even more fuel to the air/ fuel ratio making it more rich than it was before.

You want to raise the clip position to let the needle drop down lower. Lowering the needle lets less fuel through the needle jet which leans out the air/ fuel ratio.

24:1 oil ratio is very good for break in.

Also check out your clutch adjustment as others have suggested.
If the clutch is dragging enough, it will overcome the power output of the engine at idle speed and stall it.

Here's a link to a clutch how-to I did a while ago. I hope it can help you out.
http://motorbicycling.com/f4/clutch-cable-clutch-adjusting-procedures-22726.html

jon31592 · May 4, 2011

O wow... I moved the c clip to the top notch, much better mid range and much less smoke too. Got my clutch adjusted also!

Eric2.0 · May 4, 2011

jon31592 said:
O wow... I moved the c clip to the top notch, much better mid range and much less smoke too. Got my clutch adjusted also!

I wonder if this is my problem since I have the NT carb too. I have nothing to lose so I'll put the needle down and see what happens.

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Carb intake sealed, still no idle.

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