Timing question '74 318

[qwk dust]

Our '74 318 Duster has the 150 hp motor. The motor bacfires through the carb stumbles and stalls when you jump on the gas. I have put new plugs, fuel filter and fuel in her. I believe the timing is the culprit. Last night I checked the timing and with the distributor vacume line plugged it was set at 2 degrees after. I bumped it to 8 and it runs better but still not quite right. She did burn the tires with the little 2.45 open rear end though..lol.. I can continue to experiment but it would be helpful to know what the factory setting is supposed to be. My driver fender has been replaced and there is no tag. What is the suggested timing on this motor and year and at what rpm? Thanks

 

[fishy68]

I don't know the factory timing setting but I believe 8 before shouldn't cause it to backfire and stumble. Sounds like the carb. is running lean to me. I'd go through the carb. before I went any farther.

As far as timing goes you can keep advancing it 2 degrees at a time until it either spark knocks under acceleration or kicks back on the starter when you start it then back it off about 3-4 degrees and that should be the optimum setting.

 

[jomoper]

What's the condition of this motor ?
Rebuilt or original miles ?
Backfire through the carb I'd suspect a bad/sticking valve or timing chain ...

 

[qwk dust]

Original unrebuilt motor. Soon to be removed and built for some fun but I am just trying to get it running well while preping her for paint, suspension etc. I suspect the carb could use a little help also. She runs good unless you stand on it then it hesitates and pops. Once it does that she takes off like she should. I will keep advancing the timing slowly and check the carb. thx

 

[340sFastback]

You should always check the timing with the vacuum disconnected. Your best bet is to put some "timing tape" on the harmonic balancer so you can rev the motor and see what the "total timing" is. If you do get the timing tape make sure you clean that balancer with Brake Parts Cleaner and fresh paper towels so it sticks. I would try to run at 13 degrees before. If you get some timing tape look for 38 degrees total.

 

[qwk dust]

I will give it a shot tomorrow. I do check with the vacume advance plugged.

 

[340sFastback]

I will give it a shot tomorrow. I do check with the vacume advance plugged.

Ok, I read it wrong. I see you already did disconnect and plug the line, thats good. If you have not changed the pick up filter in the gas tank that could be clogged causing you problems too.

 

[mr.318]

Factory setting is @ 10 dergrees i'd put it @ 12 on that stock motor,

 

[chuckwagon2004]

Dude im having this problem and the bushing in the distributor is the culprit I believe.... Hell to ste the points too cause the shaft has some play I dunno but that sounds just like the problem with mine...

 

[yellowdartdave]

Check your accelerator pump. If it is bad it will not shoot little or no fuel when you open the throttle. Instant lean followed by a stall or backfire.

 

[C130 Chief]

Hook a vacuum gauge up to it and see what it does. If vacuum isn't steady, suspect burnt intake valve.

Don't waste your time screwing with the carb until you determine it is possible to make the engine run properly.