# Choke rule of thumb



## scastro901

I'm new to snow throwing and have limited experience with the use of carbureted engines since most of my power tools are electric, used during the summer, and my vehicles fuel injected 

I know how a carburetor works and the purpose of a choke. My curiosity is, for cold starts, I'd like to know your opinions on how you use your chokes. For example full choke vs. half choke vs. knowing when to fully turn the choke off based on indicators. Warm up times, etc.

Obviously if the engine won't start or is stalling, the choke approach needs to be adjusted (or it can be other factors). But when it's running and warming up, this is where I'm looking for opinions (especially knowing when to turn the choke off and start tossing some snow! )

Appreciate it. Thanks!


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## SlowRider22

When I start my blower, I pull the choke all the way. I leave it choked for only a couple seconds then I take the choke off...if the idle is smooth then I just leave it, if it's hesitating then I'll pull the choke back out for another couple seconds.

As for when to start throwing snow, I leave the blower on idle for a minute to allow the oil to lubricate all the internals, then I'll ramp it up to higher a higher rpm and leave it for a few minutes to warm up...this is when I typically brush the snow off the truck and shovel the stairs. By this time, the blower will have reached operate temperature and is good to go.


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## Normex

As Slowrider said full choke to start but you should tell us if you have a primer which is a rubber push action and also you should tell if your choke has 2 or 3 positions namely Full, Mid, OFF.

After your response we will be able to give you a proper procedure to get it going but again as Slowrider mentioned also you have to let the engine get warmed up some, I usually engage the auger to help for the warm up.

Norm


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## scastro901

Thanks Normex. I have a Craftsman 24-in. 208cc Dual-Stage Snowblower (model 88173).

It has a primer bulb. Choke lever has full, half and off. Throttle lever has off, then turtle to rabbit for varying speeds.


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## Shryp

Always use full throttle when operating the machine. You can turn the throttle down as you let it cool briefly before turning it off. Usually it will be full choke, 1-3 pushes of the primer and pull the rope. As soon as it starts switch to half choke and then after a few seconds no choke. Each engine is different so you will have to play around a bit to see how yours runs.


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## scastro901

Thanks. What's the hint the engine is warm and you're ready to shut the choke fully off? Does it oscillate or sputter when the fuel mixture is too rich giving you a hint you need to turn the choke off?


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## db9938

It may sputter, but remember a rich engine is also relatively cool, as compared to an neutral or leaned out engine. More than likely, you will have to take the choke off, to see if it is ready and adjust accordingly. Some of my machines take less than 30 seconds, others a tad longer.


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## Spectrum

scastro901 said:


> Thanks. What's the hint the engine is warm and you're ready to shut the choke fully off? Does it oscillate or sputter when the fuel mixture is too rich giving you a hint you need to turn the choke off?


This happens almost instantly, it's not a warm-up scenario like a car. The engine will fire and before long it will make other unhappy sounds. Just ease the choke to open and off you go. 2 or 3 go rounds and you'll be a pro.

In many cases it helps to keep a fingertip on the choke while starting. Sometimes the choke will partially reopen when it draws air. If you keep it fully closed it will pull hard for fuel and fire more predictably.


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## mkd

i've always had my carb on my 8 hp tecumseh to start and emediately let the choke off and stay running with no load. once it's running for 20-30 seconds no load i start the auger spinning for about the same time period and then go blow snow. the pilot screw is enriched so the engine doesn't starve out and die when first started and under extreme loads. same with the high speed jet, i set it up to be a tad bit richer because the machine runs cooler. if you've ever operated a lean machine at night in the dark you can see the orange glow from being hot. by adding some fuel it runs cooler and doesn't glow as much and even starts better in the extreme cold. a lean engine that runs hot also will backfire when shut down unless it is idled down so it can cool off before the engine is shut off.


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## hbsnbl123

I have a Model #247886910 CRAFTSMAN snow blower and every since it was new, after it's warmed up and I shut it off. To start, I always have to push the rubber primer otherwise it won't start Why is that? Is this normal for this Briggs & Straiten engine?


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## DuffyJr

hbsnbl123 said:


> I have a Model #247886910 CRAFTSMAN snow blower and every since it was new, after it's warmed up and I shut it off. To start, I always have to push the rubber primer otherwise it won't start Why is that? Is this normal for this Briggs & Straiten engine?


Depends on how cold and how long it's been shut off. Both my blowers will start right back up if it's only been a few minutes. Once they've been started for the first time and ran a while when I restart them I always try pulling it once first and if it don't start then add a little choke and try it, if not add more choke, only as a last resort will I push the primer bulb, I don't want to take the chance of flooding the carb.


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## CarlB

scastro901 said:


> I'm new to snow throwing and have limited experience with the use of carbureted engines since most of my power tools are electric, used during the summer, and my vehicles fuel injected
> 
> I know how a carburetor works and the purpose of a choke. My curiosity is, for cold starts, I'd like to know your opinions on how you use your chokes. For example full choke vs. half choke vs. knowing when to fully turn the choke off based on indicators. Warm up times, etc.
> 
> Obviously if the engine won't start or is stalling, the choke approach needs to be adjusted (or it can be other factors). But when it's running and warming up, this is where I'm looking for opinions (especially knowing when to turn the choke off and start tossing some snow! )
> 
> Appreciate it. Thanks!


i have found most of the honda clones like full choke to start. That being said every machine has its own personality


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## tabora

All 25-odd of my OPE engines get the same startup treatment (except for weed whackers, Troy-Bilt Blower & outboards, which also get one full squeeze of the primer bulb): 
(If it's already been running (warm) skip to step 5)

1. Turn Gas On or Open Tank Vent
2. Kill Switch Off
3. Choke On Full
4. Throttle On Full or "Start" or "Choke" Position
5. Pull Slowly Once or Start With Key
6. Pull It For Real, No More Than Twice
7. Turn Off Choke
8. If It Started, All Done; If Not, Pull 'Til It Does. (Usually Very Few Times!)


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## Oneacer

@scastro,

Every machine is in its own operating environment.

Usually, a choke is engaged, a couple prime pushes, and fire it up, and as soon as it starts to let you know by the engine sound, you will back off on the choke.

Some blowers act slightly different than others for many factors. After you start your machine a few times, you will quickly adapt to that particular machines choke functions and habits.


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## Shovel

scastro901 said:


> Thanks Normex. I have a Craftsman 24-in. 208cc Dual-Stage Snowblower (model 88173).
> 
> It has a primer bulb. Choke lever has full, half and off. Throttle lever has off, then turtle to rabbit for varying speeds.


Pretty close to what I have.
3 or 4 pumps on primer... if it's 10 f outside or colder..a couple more.
Full throttle ...then back off a touch
Full choke.
Pull the rope.
When it fires it will run cobby ..click choke back one click..let it run like that a few seconds.. then another click...wait a few seconds another click towards off..I think there are four positions..just keep going until fully off
If you start turning it off to fast it will die or the engine will hunt(speed up and slow down)..if you aren't reducing choke fast enough it will be cobby ...I can have my choke turned all the way off in a minute or so.. then I open the throttle to full fast..if it hunts I choke one click for another 30 seconds or so.
For warm starts I give about a half pump of primer..my machine won't warm start without a touch of extra fuel.




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## Shovel

scastro901 said:


> Thanks. What's the hint the engine is warm and you're ready to shut the choke fully off? Does it oscillate or sputter when the fuel mixture is too rich giving you a hint you need to turn the choke off?


If it's hunting(engine revving up and down) when the choke is fully off then it's running lean.
If your machine is cobby and smoking..stinking..it's rich
The lean condition is common and appears to usually happen from the carb getting clogged while sitting off season.
Alcohol free fuel is a must for these carbs.
I use a touch of seafoam in the fuel as a mild cleaner and corrosion inhibitor... So far so good.
You can mix it strong if you are having issues..three to five ounces a gallon.
It doesn't do miracles but sometimes do help clear partially clogged passages.
Getting to the carbs on these is a pain in the rear.. there are videos out there on it


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