Cold weather carb adjustment

[Heatingman 971]

Noticed when plowing in -10 degrees that the motor (kohler 8 hp) would want to die out if I did not have the choke part closed when the motor loaded up from releasing the clutch after a gear shift to change directions.

 

Should I increase idle, adjust fuel jets, or just use the choke like I did?

 

 

[Red-Bovine 309]

I would just keep the choke slightly pulled out. No need to mess up otherwise well set carb adjustments. 

[lynnmor 7,305]

If you have adjustable needles, by all means open them up a little at a time till it runs right.  Do not use the choke, it can be just a guess that might make it seem to run OK at a particular speed and load.  A choked carburetor cannot provide maximum power.

 

If your adjustments don’t fix the problem, it’s time to clean the inside of the carburetor.

[rmaynard 15,449]

Looks like there are two opinions here. Neither one is wrong. Both are right. That is my opinion. I have a Tecumseh on a snowblower. It always requires either a little choke or a needle adjustment. Both accomplish the same thing. It keeps the engine running and blowing snow. The next time that I start it, the same thing happens. 

In -10 degree weather, do whatever keeps you running.

[ebinmaine 67,464]

D. All of the above.  

 

[pfrederi 17,738]

Just remember how far you turn the high speed needle so you can turn it back when it warms up

[rjg854 11,361]

Generally speaking I usually have to adjust the carbs differently between summer and winter weather. Don't know why it makes a difference but it does for me anyway.

[ebinmaine 67,464]

36 minutes ago, rjg854 said:

Don't know why it makes a difference

Colder air is a fair amount more dense.  

 

[rjg854 11,361]

And that may be my problem also Eric.  

[ebinmaine 67,464]

4 minutes ago, rjg854 said:

And that may be my problem also Eric.  

 

 

 

 

Mine too brother man, now that ya bring it up.  

 

 

 

 

 

[lynnmor 7,305]

4 hours ago, rmaynard said:

Looks like there are two opinions here. Neither one is wrong. Both are right. That is my opinion. I have a Tecumseh on a snowblower. It always requires either a little choke or a needle adjustment. Both accomplish the same thing.

 

Partially closing the choke will limit the air flow thru the intake reducing engine power, adjusting the needle for the correct mixture will give the best performance.

[Heatingman 971]

29 minutes ago, lynnmor said:

 

Partially closing the choke will limit the air flow thru the intake reducing engine power, adjusting the needle for the correct mixture will give the best performance.

Assuming the same fuel is coming into play as during the summer, wouldn’t reducing the air volume to account for density maintain the same power as before?

 

For what its worth, once slightly choked, the motor didn’t miss a beat. Plenty of power.

 

 

I’ll try the main fuel adjustment and see how it does though.

Edited December 25, 2022 by Heatingman

[ebinmaine 67,464]

5 minutes ago, Heatingman said:

wouldn’t reducing the air volume to account for density maintain the same power as before?

By definition it corrects the air fuel ratio...

But it reduces the possible air flow. 

 

[Heatingman 971]

15 minutes ago, ebinmaine said:

By definition it corrects the air fuel ratio...

But it reduces the possible air flow. 

 

Right.

 

but if there is more air density, then it may be the same amount of air in the mix as when warm and choke removed. 

 

at -10 and 50% RH density is .088 lbs/ft3

 

at 70 and 50% RH density is .074 lbs/ft3

 

So if I needed more power I could up the fuel rate, bur if I Dont, then I could reduce the air.

[Pullstart 62,848]

How often do you see yourself operating at -10?  I totally agree with Lynn that you have a potential for more power, but I also agree that a little choke won’t hurt nothin’.  Even the 8 hp has spare power… you likely won’t notice much difference.

[Heatingman 971]

40 minutes ago, Pullstart said:

How often do you see yourself operating at -10?  I totally agree with Lynn that you have a potential for more power, but I also agree that a little choke won’t hurt nothin’.  Even the 8 hp has spare power… you likely won’t notice much difference.

Not often, hopefully. Guess it depends how cold this winter is. Usually only a couple days a year. And most often it doesn’t snow much when its that cold. It definitely had power to spare, probably quite a bit.
 

When I think about how much work an actual horse can do, just one of them. If a horsepower in motor terms does truly equal that of a working horse, then I could probably plow with a 1/2 horse or less. 

[Pullstart 62,848]

You can do with 3.5 hp, I know for a fact!

 

 

 

[ebinmaine 67,464]

10 minutes ago, Heatingman said:

just one of them. If a horsepower in motor terms does truly equal that of a working horse

Interesting search subject on the interwebs. 

It isn't equal. 

One healthy heavy draught horse can easily produce 15 HP or more for a short time.  

 

 

[squonk 41,098]

I'd run it with the choke. The little amount of time you're going to run it at minus 10 pales in comparison to the amount at 75° +++ . If this is a mowing machine that's when you need the torque and once it's dialed in for that, leave it.

[Horse Newbie 7,069]

1 hour ago, Pullstart said:

You can do with 3.5 hp, I know for a fact!

 

 

 

What’s the hurry in the first video ?… you we’re flying ! 😆

[Pullstart 62,848]

9 minutes ago, Horse Newbie said:

What’s the hurry in the first video ?… you we’re flying ! 😆

 

[Horse Newbie 7,069]

You are a Superman !

[Heatingman 971]

2 hours ago, Pullstart said:

You can do with 3.5 hp, I know for a fact!

 

 

 

motor didn’t even break a sweat. Really makes me wonder sometimes just how much my little 8HP could do.

 

Betting mowing is a bit more power hungry. 

[squonk 41,098]

These little tractors will run out of traction way before engine power.