It’s cold outside. Carburetor choke on stock engines.

[luvbowties]

Originally Posted by ljackson

The picture in post #22 is what my riser looks like now. The spring is on correctly. If you laid that riser down (the top of the photo away from you) it would be in the same position as it is on the truck. When the spring expands it lets the weight down into the open position and hits another stop on the short end of the weight.

In this photo you can see the other stop. The riser is upside down.

My son drove the truck today. The high temp was around 30 degrees. I hope to talk to him later to see how it did. I'll report back.

Thx for clearing up my mixup--guess I was thinking(incorrectly)that the wrong side of the flap moved clockwise. Can see it now.
Sam

[awbrown]

Originally Posted by grs

I guess I don't need the heat riser on my engine because I don't have a stock intake. My intake is a Holly. I don't think the exhaust gas will re route thru the Holly. See attachment. I don't know how to make the attachment bigger. Sorry

If you have an electric choke it is a non issue (I would still recommend that you draw hot air off the headers/exhaust manifold to keep the carb from icing ) If you have an airgap mainifold then you may experience the engine running poorly til you get some heat in the manifold .. Air gaps are more for making power ,cold air in equals more power out .. if you drive it in all kinds of weather then you should have a manifold with an exhaust crossover ... Electric chokes will not kick down automatic , you much kick the accelerator to bring the idle down ... But properly adjusted you should be able to hit the accelerator once , turnm the key and have it start and stay running at a high idle ... if it fails to do this it is not adjusted properly...

[grs]

Originally Posted by awbrown

If you have an electric choke it is a non issue (I would still recommend that you draw hot air off the headers/exhaust manifold to keep the carb from icing ) If you have an airgap mainifold then you may experience the engine running poorly til you get some heat in the manifold .. Air gaps are more for making power ,cold air in equals more power out .. if you drive it in all kinds of weather then you should have a manifold with an exhaust crossover ... Electric chokes will not kick down automatic , you much kick the accelerator to bring the idle down ... But properly adjusted you should be able to hit the accelerator once , turnm the key and have it start and stay running at a high idle ... if it fails to do this it is not adjusted properly...

Thanks

[ljackson]

We have been running it for a few days now. My sons says it warms and runs better when the engine is cold. We did have some warmer weather though. If I understand correctly, when you first start the truck you should give the accelerator pedal a quick pump. This should engage the high idle linkage. Then you should leave it alone so it stays in high idle. Is this correct? I found out yesterday that my son has not been operating it that way. This may be part of the problem?

[awbrown]

properly adjusted ,that is how it should work , no stalling ,no belching black smoke or chugging ... It should start with out pumping the accelerator ,one push of the accelerator and the choke should close and high idle cam will engage the throttle shaft adjusting screw for the high idle adjustment .. If the engine is in poor condition it will make for difficulty in getting adjustments just right ...once the engine starts the choke pulloff should open the choke far enough for it to stay running if it stalls it may be opening it to far ,I think the adjustment in that carb for the pulloff is to bend the linkage .....there are 3 adjustments , how much tension is on the choke ,how far the choke is opened by the choke pulloff, and where the high idle is set .....

[geezer#99]

Well since you have a manual choke most of what awbrown suggests won't work. I don't think you have a pull off.
With your setup you pump it twice, hold the pedal half way down, pull the choke all the way out, take your foot off the pedal, fire it up. As soon as it lights then push the choke back in about 1/3 of the way. The last setting of 1/3 depends on how it runs. You want the choke blade open about 1/4 inch.
As it warms up you can push the choke back in further which will drop the high idle.
The cable controls it all.
Would be nice to see a pic of your carb!
I know a couple mods you can do to your choke if you're interested.

[ljackson]

I was just getting ready to mention that I have this carb. # 1, Pic off the web. #2, my carb


I included the other pic to ask about advantages of changing to that one. I caused confusion. Sorry about that. Thanks to all for helping me.

[ljackson]

Originally Posted by geezer#99

Well since you have a manual choke most of what awbrown suggests won't work. I don't think you have a pull off.
With your setup you pump it twice, hold the pedal half way down, pull the choke all the way out, take your foot off the pedal, fire it up. As soon as it lights then push the choke back in about 1/3 of the way. The last setting of 1/3 depends on how it runs. You want the choke blade open about 1/4 inch.
As it warms up you can push the choke back in further which will drop the high idle.
The cable controls it all.
Would be nice to see a pic of your carb!
I know a couple mods you can do to your choke if you're interested.

I am interested in the choke mods. We plan to use a carburetor for along time. At least until any further upgrades are on my son's dime. He's 18. Just like my Dad told me years ago, "if you want that, it sounds great, pay for it and I'll help you put it in"

[geezer#99]

So from your pic I assume you removed the choke cable!

[ljackson]

Originally Posted by geezer#99

So from your pic I assume you removed the choke cable!

Sorry, the cable is installed now. When the cable is fully depressed in the cab the choke is completely open. (Flap vertical) That was the newest photo I have on my computer. I forgot to take some the other day. I'll take some of it today.

[geezer#99]

A lot of manual choke carbs have a similar cam like yours that the idle screw rides on to give you a high idle. On your carb when the choke is wide open, the idle screw is sitting on the cam like in your old pic. When the choke is closed the idle screw rides up the cam to give you a high idle. Most factory set ups are made to give you a high idle with a further closed choke plate. Problem with that is that as the motor warms up you need more choke opening to keep it from running too rich, and you still need the rpm. Pushing the choke in opens the choke but also drops the rpm and your motor might like to stall.
I always preferred more rpm with less choke opening.
On your carb that's easily done by grinding on the cam at the point where the idle screw makes contact on the cam when your choke is fully open. You only need to remove about 1/16 to 1/8 inch. THen you screw the idle screw in to maintain your idle.
Your high idle will work like normal albeit a bit higher rpm.

[ljackson]

Originally Posted by geezer#99

A lot of manual choke carbs have a similar cam like yours that the idle screw rides on to give you a high idle. On your carb when the choke is wide open, the idle screw is sitting on the cam like in your old pic. When the choke is closed the idle screw rides up the cam to give you a high idle. Most factory set ups are made to give you a high idle with a further closed choke plate. Problem with that is that as the motor warms up you need more choke opening to keep it from running too rich, and you still need the rpm. Pushing the choke in opens the choke but also drops the rpm and your motor might like to stall.
I always preferred more rpm with less choke opening.
On your carb that's easily done by grinding on the cam at the point where the idle screw makes contact on the cam when your choke is fully open. You only need to remove about 1/16 to 1/8 inch. THen you screw the idle screw in to maintain your idle.
Your high idle will work like normal albeit a bit higher rpm.

Thanks, That sounds like what I am looking for. I will see if I can do that. Just to be clear, I would take material off the entire length of the cam like in photo #2?

A few recent pics.

[geezer#99]

No!
Only at the top. Where the tip of the screw sits like in your pic.

[ljackson]

Thanks, geezer

[ljackson]

Originally Posted by geezer#99

With your setup you pump it twice, hold the pedal half way down, pull the choke all the way out, take your foot off the pedal, fire it up. As soon as it lights then push the choke back in about 1/3 of the way. The last setting of 1/3 depends on how it runs. You want the choke blade open about 1/4 inch.
As it warms up you can push the choke back in further which will drop the high idle.

I know a couple mods you can do to your choke if you're interested.

My son has been operating the choke as described above. It is starting easier and running better while the engine is cold. Air temp 20-25 degrees. I have not been able to check the blade setting yet.

We have not done the mods yet.

I did find this as a reminder to myself and for those following along:
Crankcase dilution

[geezer#99]

Good info!
Crankcase dilution is better known as fuel wash. Caused by a rich mixture getting past the rings. One of the reasons to not let your motor idle too long with a rich choke setting.
Fuel wash contributes to the early demise of many carbed motors. THe fuel washes the oil off the oil rings and cylinder promoting piston and bore wear.
Fuel injection reduced that immensely. The old carbed motors where good for 100,000 miles before rebuild and now the fi motors are good for up to 350,000 miles.
Good to see it's working better for him!