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How to Identify and Fix Common Gardening Problems ?

We provide a variety of viewpoints on how to identify and fix common gardening problems. Our sources include academic articles, blog posts, and personal essays from experienced gardeners :

An engine`s idle is firstly set by a simple throttle stop, known as an idle screw. This screw takes its position on the side of the throttle body and stops the throttle linkage arm from completely shutting the butterfly valve that allows air to enter the intake manifold.
Typically, engines idle at about 600-800 rpm. Older engines may go up to 1200 rpm or more while warming up. But if the engine is revving up while idling, even after it`s sufficiently warmed up, you might have a problem. High idle speeds waste fuel, cause extra wear and tear on your engine, and can be unsafe as well.
Locating the Idle Air Control Valve

The IACV is usually located on the intake manifold near the back of the throttle body.

An idle air control valve, also called an idle air sensor control motor, is an electrically operated valve that controls the amount of air that bypasses the throttle plate in cars with a fuel injection system [source: Autozone]. This causes the idling speed of the engine to change as needed.
The goal of adjusting the idle-mixture screws is to achieve the highest possible idle vacuum at a set idle speed. If the idle speed increases after you adjust the idle-mixture screws (which is likely), be sure to adjust the idle speed back to the base speed.

Discover Relevant Questions and Answers for Your Specific Issue

the most relevant questions and answers related to your specific issue

The engine idles way too fast and will not correct with the sow speed adjustment
ANSWER : Make sure that you are adjusting the idle speed screw, not the idle jet screw (L). If you are adjusting the proper screw, then it is possible that the throttle trigger assembly in the handle has a load of sawdust/dirt that blocks proper return to idle. Take the handle apart carefully, and make notes on how the parts go back together. Check at the carburetor throttle assembly to make sure the throttle arm returns fully to the idle speed screw when the trigger is pulled and released slowly. Check the throttle spring as well to make sure it is undamaged. Hope this helps!

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Idle goes up and down and the shuts off eventually
ANSWER : It sounds like the engine might be running too lean. You need to get someone to adjust the idle and high speed screws correctly.

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ANSWER : All the pictures I have of this carb show two adjusting screws.

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Where is the idle adjustment screw on my 42/18
ANSWER : On the left side of saw above primer button is a hole going to the carb, the screw is there below switches.

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How do i set idle for 25cc gas trimmer? – Craftsman 25cc Gas Line Trimmer
ANSWER : James is right about setting the idle mixture.

Do you want to set the idle speed?

That can be done with the screw that sits on top the carb and holds the throttle stop. Just work the throttle while looking at the end of the cable at the carb and you will see something stopping it at idle that has a screw in it. Move this screw in or out to adjust idle speed.

If you dont have good throttle response off idle you should adjust the hi speed mixture at wide open throttle and then go back and do the low speed changes. Mixture and then speed adjust.

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Member Discussion on Husqvarna 240e Chainsaw Idle Adjustment I have a new 240e and cannot keep it running. It will start, after many pulls, and one of two things happens. After running for 30 seconds, I will tap the trigger to set the idle and it will promptly idle down and die. Or, I do nothing, and it will idle for a bit and die. Restarts are difficult. I did not get a manual with the saw, so all I have to work with is one I downloaded. Idle adjustment is mentioned, but no indication where this adjustment might be. Thanks
ANSWER : Its not an idle screw adjustment issue, it is a mixture screw adjustment issue, unfortunatly there is a special tool to adjust the mixture screws, pt no. 530035560 ( available from Hysqvarna dealers ) once you have this tool you can make an adjustment to the L screw on the carb, undo ( anti clock wise ) this screw ten minutes on a clock face ,this will richen the muxture, and should make it more stable on idle.

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My saw idles way too fast – how do I adjust? – Homelite Gas, 20 In. Bar, 46 CC, Chain Saw, UT10520
ANSWER : Threr will be three adjuster screws on the carb ( will be holes in the cover so as to acess without removing any covers ) they will be marked L H and I( for idle ) or T( for tickover ). The T or I screw will adjust the idle speed, unscrew anti clockwise to reduce the speed.

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Craftsman 28cc 16" chainsaw wont idle – Craftsman 38cc 16" Gas Chain Saw
ANSWER : If you’ve already tried the idle adjustment screw and that didn’t work, you need to turn the low side adjustment CCW a quarter turn and try again.

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