Quadrabog bogs

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iamtherealJayy

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I’m having problems understanding the mixture screws. I set them both 1-1/2 and idle at 750 then started turning one out and idle went up to about 1000 and nothing changed after that so I lowered idle back to 750. I think I’m gonna shut the truck off and restart at 1-1/2 so I can count the turns. One started around 4 turns out and the other around 3-3/4
 

iamtherealJayy

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So me fiddling with the screws helped a little but it’s still bogging down and stalling when I let off. It doesn’t do it as suddenly but it’s still doing it. I also noticed white smoke constantly from the tailpipe, do I have a bigger issue with this engine? I know the battery is a problem. I stalled it and now I’m waiting to jump start it because it won’t crank fast enough.
 

Bextreme04

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If the alternator isn't charging and your battery is too dead to even crank it, you probably aren't getting good spark.

When you adjust the mixture screws, you need to slowly back them out and then as the idle is rising, loosen the idle screw to keep the idle lower. You shouldn't be letting it get anywhere near 1000 RPM. When unscrewing the mixture screws stops raising the idle, then set the idle to 750 and screw in the mixture screw until the RPM drops by 50-100RPM.
 

iamtherealJayy

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My tachometer isn’t that precise. It was constantly bouncing 5-100 rpms pretty much. I was turning them a half turn at a time out then turning them in slowly until it dropped. If my calculations are even close to correct I’m less than 1-1/2 turns out… which doesn’t seem right to me?
 

iamtherealJayy

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Here’s the video right after tuning
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And here’s after I got a jump start, yes it stalled again at the end.
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Bextreme04

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My tachometer isn’t that precise. It was constantly bouncing 5-100 rpms pretty much. I was turning them a half turn at a time out then turning them in slowly until it dropped. If my calculations are even close to correct I’m less than 1-1/2 turns out… which doesn’t seem right to me?
It went from 750 to 1000 RPM in less than 1 turn? And then you needed to turn it more than that back in to get it to drop 50 RPM?

Now I'm confused... You have the two idle mixture screws on either side on the front of the base. The idle set screw on the drivers side of the throttle shaft and the high idle screw on the passenger side of the throttle shaft. They are 4 separate screws.
 

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What is the timing set at? What does your vacuum gauge look like when its hooked up and running? Is it dying when you press the gas or when you let off?
 

iamtherealJayy

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No no no lol I completely redid it because I felt like I was wrong the first time. The first time I kept unscrewing them because the idle kept going up. I then restarted back at 1-1/2 and did the process all over. This time I got to about 2-3/4 turns out then turned them back in more than a full turn each before idle would drop and I’d have to raise it. I ended up with a little less than 1-1/2 turns out if my math was correct.
 

iamtherealJayy

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I have no idea on timing. My timing light disappeared somewhere between work and home. It bogs on throttle and it’s too loud to really tell exactly when it stalls but I’m off the throttle when I realize it’s dead. So I’m going with bog on throttle and stalls when you let off. I’m thinking the white smoke might be coolant.. radiator is low and the gauge was about straight up when I stopped.
 

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I have no idea on timing. My timing light disappeared somewhere between work and home. It bogs on throttle and it’s too loud to really tell exactly when it stalls but I’m off the throttle when I realize it’s dead. So I’m going with bog on throttle and stalls when you let off. I’m thinking the white smoke might be coolant.. radiator is low and the gauge was about straight up when I stopped.
well, that's not good
 

iamtherealJayy

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I don’t feel as I’m concentrated enough to do the rpm tuning. And my cheap $25 tachometer isn’t precise enough. I’m not sure if you’re referring to the smoke as not good or my tuning as not good. Neither seem too great in my opinion. I admit I think I made it better but I just can’t wrap my head around it. I backed them about 1-1/4 turn out or so to raise rpm but had to screw them back in more than that to drop rpm? I did blip the throttle every time I adjusted the idle screw and let it fully smooth back out.
 

iamtherealJayy

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Alright I take it back. The water neck is wet, that’s where the coolant went. Can fuel make a white smoke? I thought fuel made a black smoke? It’s pretty good smoke show at idle but any amount of throttle blows it right away and it takes a second to come back. Is there anyway I can verify fuel/coolant? I know running rich you can smell fuel but I honestly haven’t gotten that close to the exhaust and taken a deep inhale of CO to tell. If it’s from fuel I’m not as concerned, that’s easier to fix than if it’s coolant lol I really don’t want to rebuild this engine already n
 

Bextreme04

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I don’t feel as I’m concentrated enough to do the rpm tuning. And my cheap $25 tachometer isn’t precise enough. I’m not sure if you’re referring to the smoke as not good or my tuning as not good. Neither seem too great in my opinion. I admit I think I made it better but I just can’t wrap my head around it. I backed them about 1-1/4 turn out or so to raise rpm but had to screw them back in more than that to drop rpm? I did blip the throttle every time I adjusted the idle screw and let it fully smooth back out.
You don't use the mixture screws to adjust RPM. RPM will move around on its own as you adjust them, use the idle screw to adjust RPM to keep it around 750 as you adjust the mixture screw(s). When the RPM stops going up on its own as you unscrew the mixture screws, you stop adjusting the mixture screws and then make sure your RPM is at 750(only adjust the RPM using the idle screw at this point!!). Then screw in the mixture screws until you hear or can see the RPM just barely start to come down(50-100rpm max).
 

Bextreme04

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You really need a timing light, vacuum gauge, and voltmeter. Check to make sure you are getting at least 12.7v at the battery. Check initial timing with vacuum line disconnected at the carb and vacuum gauge connected there. If the vacuum at idle is smooth and at the 18-20 in hg range, the motor probably isn't hurt too bad. White is almost always coolant or condensation. You said its been really wet and raining, it might not be a real problem.
 

iamtherealJayy

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Yes that is what I did, the smaller annoying flat head screws are the mix screws the nice bigger flat head screw attached to the throttle linkage is the idle speed screw.
 

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