Running with choke partly on

flood · #1 06-30-2016, 02:19 PM

My 147 has gotten so it won't run well unless the choke is partly on. Haven't rebuilt the carb in several years, and I know I should do it again, but is there any harm in running it as it. Seems to run great.

lindstromjd · #2 06-30-2016, 02:34 PM

Well, since you have to run with the choke engaged, you'll be running rich. It will foul up the plug and possibly the exhaust valve from carbon build up.

J-Mech · #3 06-30-2016, 02:45 PM

Quote:

Originally Posted by lindstromjd

Well, since you have to run with the choke engaged, you'll be running rich. It will foul up the plug and possibly the exhaust valve from carbon build up.

Ummmm...... no.

If you have to run with the choke on, the carb has went lean. Yes, you can damage the engine running it like this. Lean on fuel causes excessive heat, and can damage the piston.

drglinski · #4 07-01-2016, 08:42 AM

Yup, only gonna get worse. Get it fixed before you've gotta fix a whole lot.

Rmowl · #5 07-02-2016, 01:24 PM

Sounds bad, probably oughta let me go ahead and take it off your hands for you and coax her back to life seeing as how your in MD as well. Ha! Rebuild carb should be a ok, dare I say consider running stabil ethanol treatment in your fuel?

lindstromjd · #6 07-07-2016, 12:13 AM

Quote:

Originally Posted by J-Mech

Ummmm...... no.

If you have to run with the choke on, the carb has went lean. Yes, you can damage the engine running it like this. Lean on fuel causes excessive heat, and can damage the piston.

Grammar and English there, captain. I said WILL BE, not HAS GONE. If you have the choke engaged, it creates a rich mixture. Yes, his carb HAS GONE lean because it's not putting out enough fuel, creating the need to engage the choke to cut out the "excess" air. You need to read what's actually there, and not what you THINK is there. We said the same thing, and you turned it argumentative because you wanted to.

J-Mech · #7 07-14-2016, 01:05 PM

Quote:

Originally Posted by lindstromjd

Grammar and English there, captain. I said WILL BE, not HAS GONE. If you have the choke engaged, it creates a rich mixture. Yes, his carb HAS GONE lean because it's not putting out enough fuel, creating the need to engage the choke to cut out the "excess" air. You need to read what's actually there, and not what you THINK is there. We said the same thing, and you turned it argumentative because you wanted to.

No, if the carb has gone lean, using the choke cuts the air down making the mixture correct again. But, since the choke is on and air is cut down, it is still lean because it can't draw the air needed. We DID NOT say the same thing. You are incorrect. I was being argumentative because your wrong.

lindstromjd · #8 07-14-2016, 01:17 PM

Quote:

Originally Posted by J-Mech

No, if the carb has gone lean, using the choke cuts the air down making the mixture correct again. But, since the choke is on and air is cut down, it is still lean because it can't draw the air needed. We DID NOT say the same thing. You are incorrect. I was being argumentative because your wrong.

How can the carb mixture be "correct" and "lean" at the same time by using the choke? That makes literally no practical sense whatsoever.

The only thing that will be lacking if the mixture is magically good with the choke in exactly the right position, is the CFM flowing through the carb. If the choke is off one way or the other at all, then his mixture is off regardless.

J-Mech · #9 07-14-2016, 01:25 PM

Quote:

Originally Posted by lindstromjd

How can the carb mixture be "correct" and "lean" at the same time by using the choke? That makes literally no practical sense whatsoever.

Only because you don't understand.

The carb is lean. He corrected it with the choke, which cut down the air. The carb is still lean.... You stated:

Quote:

Well, since you have to run with the choke engaged, you'll be running rich. It will foul up the plug and possibly the exhaust valve from carbon build up.

That is not true. If you want to debate engines with me, you need to at least understand how they work.

lindstromjd · #10 07-14-2016, 02:02 PM

Quote:

Originally Posted by J-Mech

Only because you don't understand.

The carb is lean. He corrected it with the choke, which cut down the air. The carb is still lean.... You stated:

That is not true. If you want to debate engines with me, you need to at least understand how they work.

So the carb is lean because it no longer puts out the proper amount of fuel for the airflow through it. He uses the choke to cut down air, which makes his mixture correct-ish again. Which means he is not lean on fuel or air, he is lacking in CFM flow through the carb. So if his mixture is no longer lean or rich, then he's not going to run hot (like you said) or cold because it's rich. He's just not going to produce the full power that the throttle is asking for.

I stand by what I said. If he uses the choke to run, it cuts out air, which makes a rich mixture. Now, if he gets it right and has the choke in a position that doesn't create a rich mixture, you are still wrong about him running hot due to lack of fuel in the mixture. Only time he'll run hot is if he runs without the choke at all until he fixes the issue.