Carb idle adjust - NO JOY

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Larry in IN
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Carb idle adjust - NO JOY

Postby Larry in IN » Tue Aug 02, 2016 4:14 pm

Hi all,
First time back for a while - fun to see familiar names and some new ones...
My 59 +/- cub runs well w/ the choke fully pulled, but as soon as it comes open just a bit, it dies, starved I presume.
:lost:
I have run the idle adjust screw all in and way out, neither seems to make any difference.
What am I missing?
Thanks,

Larry in IN
May God Continue to Bless America!
One of the few advantages of growing older is that I finally realized that I haven't made ALL the stupid mistakes! Yet!

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raystractors
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Re: Carb idle adjust - NO JOY

Postby raystractors » Tue Aug 02, 2016 4:27 pm

It sound like you have the jet partly blocked. Have you taken the jet out of the side of the carb yet? There are several posts about this trouble if you use the search feature. There is a brass colored nut on the out side of the carb, turn the fuel off and remove this brass nut. This is the jet that I was talking about, then use a small strand of copper wire to clean out the jet, some carb cleaner is also good for this. After cleaning the jet turn the fuel on without replacing the jet. you should get a good full stream of gas thru the carb. If not then you have a blockage somewhere up stream from the carb. Good luck

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ricky racer
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Re: Carb idle adjust - NO JOY

Postby ricky racer » Tue Aug 02, 2016 4:47 pm

raystractors wrote:It sound like you have the jet partly blocked. Have you taken the jet out of the side of the carb yet? There are several posts about this trouble if you use the search feature. There is a brass colored nut on the out side of the carb, turn the fuel off and remove this brass nut. This is the jet that I was talking about, then use a small strand of copper wire to clean out the jet, some carb cleaner is also good for this. After cleaning the jet turn the fuel on without replacing the jet. you should get a good full stream of gas thru the carb. If not then you have a blockage somewhere up stream from the carb. Good luck

:Dito:
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Bob McCarty
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Re: Carb idle adjust - NO JOY

Postby Bob McCarty » Tue Aug 02, 2016 6:35 pm

That screw is for the transition from low to high throttle. Starting point is gently all the way in and then 1 1/2 turns out. As suggested, check the main jet.

Bob
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we need to think differently."
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mva1958
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Re: Carb idle adjust - NO JOY

Postby mva1958 » Wed Aug 03, 2016 6:58 am

Don't over-tighten the main jet screw when you reinstall it, it will snap at the middle. Don't ask how I know this... snug it up and open the fuel cock, if it drips tighten it carefully. Don't forget the little washer.
If only Mrs. Hoyt and Mrs. Clagwell had gotten along...

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Re: Carb idle adjust - NO JOY

Postby Cub driver » Thu Aug 04, 2016 8:36 am

Does sound like the main jet is partially blocked, I use a cutting torch tip cleaner and carb spray..... the tip cleaner works wonders.

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Re: Carb idle adjust - NO JOY

Postby Jim Becker » Thu Aug 04, 2016 8:46 am

Don't use a torch tip cleaner. It will enlarge the jet. Use something soft, like a telephone wire.

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Re: Carb idle adjust - NO JOY

Postby Crimson Tim » Wed Aug 17, 2016 12:36 pm

Bob McCarty wrote:That screw is for the transition from low to high throttle. Starting point is gently all the way in and then 1 1/2 turns out.



This is in reference to the IH carb, yes?
Do you know if this is also true for the zenith?


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