Timing issue?

[70DUSTER/74SCAMP]

What does out the tailpipe look like?
Black ?

White ???

black

 

[70DUSTER/74SCAMP]

Original stock 318 engine, or rebuilt engine?

original to my knowledge was bout on craigslist

 

[70DUSTER/74SCAMP]

Coil gets hot and starts to missfire. Swap the other coil on from your other A body and give it a try. Have had coils go bad like that.

brand new msd coil blaster 2 a week old

 

[70DUSTER/74SCAMP]

You can’t adjust a float on the secondary side if it’s already full.

Your not using fuel out of the secondaries sitting at idle and that’s why you see no change when you screw the adjustment down.
Loosen the bowl and drain it.
Then screw you adjuster clock wise until it lightly stops.
Start the motor and start backing out the needle and seat adjustment as you watch for the fuel to come up to the level.
Tighten down the locking nut.

the adjustment screw will stop at some point when i screw it out? it acts like it will come right out all the way . i get what ur saying tho thanks for the info

 

[70DUSTER/74SCAMP]

Once it warms up and starts to miss and stumble at idle, spray some starting fluid down the carb and see if it comes out of the stumble.

This will tell us if it is ruining out of fuel after it warms up.

Edit:
Same thing when it warms up and starts to miss, start closing off the choke plate and see if it comes around or just dies. ☆☆☆

its getting plenty of gas i can see the levels in the sight glass when its hot back sight glass is full front is half always.

 

[70DUSTER/74SCAMP]

If it's running lean, yes. If it's running rich. It might smooth out a bit and the RPM's would go up.

is this a temp fix i mean surely i cant leave it open ? and i have heard of people leaving the vacuum advance completely off any truth to that?

 

[George Jets]

is this a temp fix i mean surely i cant leave it open ? and i have heard of people leaving the vacuum advance completely off any truth to that?

This is a test to see if it is running rich. YOUR tail pipe is running black suggesting rich.

Warm it up then pull one of the vacuum ports open to introduce more air into the manifold. Like on the 1406 the driver's front vacuum port below the butterflies going direct into the manifold.

Or pull the power brake vacuum hose off on the rear of the intake manifold.

If this test speeds up the engine and smooths the engine out. Then you know it is running RICH.

Then we go from there on the diagnostics.

 

[George Jets]

 

[AJ/FormS]

could the intake manifold gasket be causing this maybe once the engine warms up gasket may leak but runs decent when its cold or just started? gasket looks a little ruff maybe in places it is an edelbrock performer rpm foro a thermo quad but im running new square bore gaskets and a summit one inch carb spacer all new on it. no leaks on that part

"could the intake manifold gasket be causing this"
I seriously doubt it.
"im running new square bore gaskets and a summit one inch carb spacer all new on it. no leaks on that part"
Are you making assumptions? or have you tested them?

i would hope not considering it was new out of the box 2 days ago lol. from summit like i mentioned. but thank u for the info i may check that out. got the primary float set just fine its just the back is full at idle.

Obviously the rear level is waaaay high.
New don't meanchit any more.
You're gonna need to learn about carbs and such, so you might as well order a Book. If you have an electric choke, then for sure it should have a fast-idle screw on the passenger side, and a mechanical interlock to prevent the secondaries from opening when the choke is on.
My Mopes have never much cared about what brand of plug is in it. The Champions that are in it today were installed in 1999, and have over 100,000 miles on them.
Your vacuum advance us not the problem unless you hooked it up to full-time vacuum and then set your timing to 10* advance. This is full-time wrong for your engine, and fails on two counts.
1) if the engine loses vacuum, for whatever reason, to the point that the vacuum drops out,then the idle speed will drop, maybe enough to stall. and
2) when you nail the gaspedal, vacuum drops very low , and if the engine has a stock timing curve, and was idle-timed with FT advance, it will not have near enough PowerTiming.Yur gonna need another Book.
on a different note;
Are you still running the factory log exhaust manifolds and single exhaust? If yes, make sure something is coming out the tailpipe at speed.

 

[George Jets]

^^^^^
Obviously the rear level is waaaay high.

☆

 

[Bewy]

If the sec float level will not adjust [ sight glass full of fuel ], it needs to be FIXED.
Possible causes:
- n/s binding
- debris in n/s
- float binding
- float fuel logged.


'Course, you could fit a reliable Edel AFB or AVS...& use the Holley for a door stop. They are also very good as a weight to stop the garbage bin lid blowing away in a wind....

 

[furrystump]

It is dripping fuel out of the rear boosters. When it is running bad look down inside the secondaries. You should see no dripping fuel. Fuel heats up gets bigger and the float level gets that much higher. Maybe? More dripping. You can pull both bowls. Measure the distance on the “correct” front bowl. From the top of the float to the bowl edge. Holding it upside down. Then get the back one a hair bigger gap between the top of the float and the top of the bowl. You can stick drill bits in to measure. It should get you close. It at the very least will stop it from dripping fuel out of the secondary booster.

 

[yellow rose]

Take the rear float bowl off. Turn it upside down. The adjust the float so that the top of the float is parallel to the top of the float bowl. Then go one turn (or a bit more) LOWER. Put the bowl back on. The float level should now be low. Start the engine and let it warm up a bit and then slowly raise the float until it’s up about 1/3rd of the sight glass and leave it.

IMO, half way up the sight glass is too nigh for most engines.

 

[George Jets]

 

[Krooser]

If your rear float is too high pull the rear fuel bowl. Look at the float hinge and you will see a little silver tang that is stamped into the float arm. You will MAY have to bend that tang "up" just a bit. That is what contacts the needle/seat and controls how much float adjustment is available.

If you float arm has a simple "bulge" instead of the tang you will likely have to carefully bend the float arm DOWN a bit at a time until the fuel level adjustment can be made with the lock nut..

I had to do this today while assembling my race carb. The factory adjustment of that tang was way off...

The above video is an excellent guide...

 

[DJC]

I adjusted the front float to middle level of the sight glass . used a 5/8 wrench and went clockwise to lower the float. i did that on the rear and it just bottomed out no more adjustment and sight glass is plum full in secondary. using a stock pump mechanical. i get how techinically just dont know why it wouldnt lower the float. front went down just fine like i said it just bottoms out no more adjustment to give.

From a Holley forum
Float And Fuel Level Adjustments On Holley Four-Barrel Carburetors - Blogs - Holley Performance Products Forums

a) Begin by lowering the fuel level in the fuel bowl to bring down the float. With the engine off, remove the sight plug and allow excess fuel to drain from the sight plug into a rag. Rock the vehicle a little to slosh additional fuel out of the bowl. Failure to lower the fuel level below the sight plug before adjustment will result in a bottomed out float in the floor of bowl.