Extended start/cranking question (1 Viewer)

Joined
Sep 4, 2018
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Austin, Texas
Hey guys,

I am wondering if this is an issue or just normal for a 40 year old, carbureted engine.

My rig will consistently start but the cranking time is always unpredictable. Usually, I can count on the first crank of the day failing (no choke), second try always starts but generally takes 5-6 seconds of cranking and press the gas pedal lightly a few times. This seems pretty normal to me, correct me if I am wrong.

The other times that makes me wonder if I have an issue is when I have driven it 3-5 miles, run into a store or something, then quickly come back out - often times, it will again, do an extended cranking 5-6 seconds with having to press the gas a bit. Sometimes in the same scenario, it will start immediately turn key. Not sure what causes the difference.

Does the carb need to be adjusted possibly? Ovbiously, it would be great to start immediately each time on the turn of the key...is this unrealistic? haha.
 

73FJ40

After another night of rust removal!
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Is this your first 1970's carbureted engine with manual choke?

Have you any experience with carbureted chainsaws, lawnmowers, snow-throwers (oops, Texas!) etc?

Primer bulb, choke lever, throttle lever, etc.?
 

73FJ40

After another night of rust removal!
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Haha, I am a newbie. I’ve had a 79 before as well but it’s been years ago. This must be pretty normal then I assume
Please go back and read my updated post. There is a procedure to follow when dealing with "classic" technology.
 
Joined
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Yes, I don’t live in glass box actually so I am familiar with priming a carbed engine. I am wondering why it still proceeds to have an extended crank after it has already been running. This doesn’t seem normal to me.
 

73FJ40

After another night of rust removal!
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My point is that these manual-type carbureted systems need some extra thought, learned through trial and error, to get it right.

Here in MA, when the engine's cold overnight, pull the choke all the way and one or two full pumps to the floor of the pedal (accel. pump squirts raw gas down the throat of the carb) and foot off the pedal. This also allows the carb linkage to set up on high idle cam.

"Hot", full pedal (squirt gas) then partial pedal.

Sometimes this floods the engine, so you have to crank with the pedal floored until the rich condition passes. or wait.

Engine sitting unstarted for a week or more, the float bowl would be dry. I would pop the hood, pop the air cleaner off the carb, and pour an ounce of gas down the throat. Close it up and start it with the choke on.

Also, check the sight glass on the carb (assuming stock Aisin carb) to make sure the float bowl has gas for the the accel pedal to pump.

Don't know what your climate and carb conditions are, but these classics are much more finicky than fuel injected O2 sensored, Mass air flow sensored engines of today.
 

rkymtnflyfisher

Big Government Sucks
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Choke.
Pump twice.
Fire it up.

That's my cold weather starting ritual, usually fires up on the first couple turns.


Make sure you are starting with a properly tuned carb.
 

rkymtnflyfisher

Big Government Sucks
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Even if I let mine sit for a week or two it fires up reliably, maybe a couple extra seconds, but not much more.
 
Joined
Jan 19, 2018
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Ontario
Same...2-3 pumps and choke consistently works, even in middle of winter.
I find it will rarely start on first crank cold without the choke.
 

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