Passenger Side Plugs Fouling / Ds Looks Good ??

Last weekend wife and I were trail riding for several hours. Power was down very noticeably by the end of the trip. Maybe 3hrs of mostly low speed / low RPM bumping along. I cleaned these up, re-gapped and reinstalled. Also put in Pentronix ignition that was sitting on my shelf of several months. Everything is much better this week.

But why did the passenger side load up so bad and driver side looks pretty good? Dauntless V6....

 

I would look at the others plugs on the PS. If they are all like that I would turn in the fuel mixture screw on that side 1/4 - 1/2 turn. If only one is fouled then start looking at other things. The DS looks great and the PS is not far off.

 

Conventionally you are supposed to adjust both idle screws the same. If you want you can lean up idle generally. I'd first test that they are both turned out the same amount. Then I would run at idle and turn each in the same amount a bit at a time until the idle starts to stumble. Then back out just until it smooths out. This would be "best lean idle" and what Jeep specifies from ca '72 on.

I would also test that the throttle plate is closing completely and that I had no vacuum leaks. You should be able to stall the engine by turning the idle mixture screws all the way in. You should also be able to stall the engine by backing out the idle stop screw to slow the engine. If either test fails, could be that you have a vacuum leak that favors one side, leaning it out.

 

O

One of the plugs on DSide was clearly worse than the other two. I have no idea what screws are what and never have adjusted a carb - But what the hell - I'll shoot some photos and y'all can learn me!

 

My carb is similar, there are two screws w/ springs on the front.



I mailed it off for rebuild last year.




I guess I'll start with turning both all the way in and count the turns. Then start on the tests Tim posted above. I'll post my results. Thanks for everyone's help

 

Do not tighten the air mixture screws tight! This can damage the fine needle point on them! Gentle turn them in till they just “seat”
Then count 2 full turns out for each, this is a good bench mark to start with. A vacuum gauge is the tool to use.

 

Yes! Exactly. I have a parts Rochester 2G where someone tighten the screws so tight in that it actually damaged the carb lower base, enlarged the actual holes!!

 

idle screws . you need a old school tool

 

I second using a vacuum gauge to tune.

 

I was having issues fouling three of the plugs and the others being good. Wrong distributor cap was the culprit. There are 3 for the Dauntless if I remember correctly.

 

well how the heck would I know?

 

I got home from work a little late so I just checked the screws. Both were out just over 3turns. I set them at 2.5 turns out then spent the rest of the evening cleaning guns.

Florida went to “shelter in place” starting tomorrow so I’ll have plenty of extra time at home for the next few weeks.

 

I had to order all 3 and try them individually. I ruled out the prestolite pretty easily. it doesn't have the window for adjusting dwell. The two Delco ones will be your choices then. If there are 2 different Delco rotors, order both but keep them with their corresponding caps. Try 1, drive it. Notice the smoothness and power level. Try the 2nd one. Same deal. It will be apparent. I imagine you could also throw on a vacuum gauge and whatever one reads more vacuum, will probably be the correct cap and rotor. Apparently the earlier points Delcos (up to 1967) had a different cap than the later, (68 and later) cap. Also the inline 6 Chevys of that era had a cap that would fit but not be correct. It was in the clocking of the cap that they were different.

 

Keep in mind that the difference is not huge. The Dauntless will run, but it won't seem "right". I would consistently, but not really quickly foul 3 plugs and the exhaust smelled a little gassy. When you have the two different Cap combinations tried one after the other, it will be pretty easy to figure out which one works for your engine. Be friends with your parts guy and explain your predicament and I would bet they would take the wrong parts back when you get it figured out. The problem was a real head scratcher for me.

 

James is correct here...this is called a dual plane intake manifold & it's how almost all V-type engines are set up.