Good morning all.
I have a 555 BBC, Basic motor.
Dart 355 heads, 808/786 roller cam, 14.1 compression, Victor Jr intake, Quick Fuel 1150,
MSD AL3 Red Box, Tower coil, QX starter. 16 volt battery.Just basic stuff.
When trying to start it, it will spin over then kick back and belch threw the carb, sometimes catching on fire. I have broken at least 2 flex plates.
I have changed the plugs, wires, tested the MSD and all seems to be in order. I even tried a CFM 1150 carb off another car that starts just fine.
Any ideas will be appreciated
Thanks
Calvin 1177 SST/SG
Just a First RD Duck, looking for a win!!!

Timing?

Rotor phasing?

It's a polarity problem. Analog you want the most retard.

I'm sure you have the violet wire to the violet wire at the plug now. Switch that green to violet.

Also double check the polarity on the crank trigger wheel, I know a guy who melted a truckload full of pistons using nitrous, before finding bad polarity on a crank trigger wheel.

Hold a magnet over the top of each magnet on the wheel, both sides of the wheel, the magnet you're dangling over the magnet on the wheel will be pushed to the same side, if the polarity is correct.

This message has been edited. Last edited by: Mike Rietow,

Are you using start retard? If so turn it off

The trigger wheel should have an arrow for direction of rotation, make sure you have it installed correctly.

^^^ All of the above…….. and

Try a different 7al3 box if possible. Or if someone has a 7al2 or even a 6al to try replacing with and try.

If it is bad or you consider it not operating correctly, call MSD with the box serial # to confirm how old it is. If less than 10 years old, consider sending the box back to MSD to confirm operation.

If this 7al3 red box (7230) is 20 or more years old, and “if” I owned it, I’d replace it with the newer (7330) 7al3 Black box if wanting to stay with analog ignition. Many are using this newer analog ignition box with great results.

David Lanning ( Lanning Electric) had posted several years ago, that he went through 4 different 7al3 red boxes to find one that he felt worked properly back when he still used these.

quote:

Originally posted by Brktracer:
Rotor phasing?

X2

I broke bunch of flex plates behind 500 cu in pro stock engine in a hard tail dragster. Removed the MSD start retard - no more problems. Had a friend with same problem, removed start retard - no more issues.

quote:

Originally posted by jdbsmith:
I broke bunch of flex plates behind 500 cu in pro stock engine in a hard tail dragster. Removed the MSD start retard - no more problems. Had a friend with same problem, removed start retard - no more issues.

I have had exactly that as well.

You need to address the problem but the 139 tooth flexplate will eliminate broken teeth. One of best investments I have made.

The OP doesn't state if he is using a crank trigger or a distributor with a pick up in it. That would be helpful information to point you in the right direction.

quote:

Originally posted by Cal of MD:
Good morning all.
I have a 555 BBC, Basic motor.
Dart 355 heads, 808/786 roller cam, 14.1 compression, Victor Jr intake, Quick Fuel 1150,
MSD AL3 Red Box, Tower coil, QX starter. 16 volt battery.Just basic stuff.
When trying to start it, it will spin over then kick back and belch threw the carb, sometimes catching on fire. I have broken at least 2 flex plates.
I have changed the plugs, wires, tested the MSD and all seems to be in order. I even tried a CFM 1150 carb off another car that starts just fine.
Any ideas will be appreciated
Thanks
Calvin 1177 SST/SG
Just a First RD Duck, looking for a win!!!

First that Red 7AL3 can be evil without you having a clue! Even if it is not the issue, GET RID OF IT!

Is this a new issue or a new combo? Sounds like the timing is too far advanced for whatever reason. Check rotor phasing first, even if you don't use a crank trigger. If you are using a slip collar distributor, check to ensure the distributor shaft hasn't rotated within the collar!

Start retard is a trial and error deal, some motors like it and some don't! 0 to 10 degrees, try in 2 degree intervals to find the best.

If you check the basics and don't find any smoking guns, borrow someone's MSD box and try that.

Had the same thing but found the ignition timing had moved when the crank trigger moved. Rotor phasing and timing is about the only thing that causes a backfire.

quote:

Originally posted by TOP38: First that Red 7AL3 can be evil without you having a clue! Even if it is not the issue, GET RID OF IT!

I agree with this statement. Even if not the problem now, these older model 7al3 Red boxes are the next problem waiting to happen in your ignition system imho.

ROTOR PHASING....number one....
If it's off even a little and the spark jumps to the wrong terminal you'll get wicked kickbacks...

Don't use any start retard.

I have had the problem so bad it wrecked a 139 tooth starter armature. Before that I wrecked 2 168 flexplates.

I went over everything and the rotor phasing was the only thing I adjusted and the problem went away...

At the time my engine was Ron's injected.
For a while I did use a start retard of 10-15 degrees and was starting on a Primer Plus...Start retard was activated when Primer plus pump was turned on.....
Engine actually starts easier and better with NO retard....

A 139 tooth flexplate will live when a 168 will lose a tooth...

I have found that contrary to what everyone likes to do and says they do....

I turn ignition on as soon as I crank the engine.....Most of the time starts immediately....

Cold starts are more likely to kick back.....I had a few last year first start of the day.....

Pump it a few times.....spin engine over ignition off.....then start it.....

Severe kickbacks......rotor phasing is the first place I'm looking...

Rotor should be dead on cap terminal or slightly ahead....very slightly...

Some people used to file the rotors down to be more of a point.....

quote:

Originally posted by markemark:

quote:

Originally posted by TOP38: First that Red 7AL3 can be evil without you having a clue! Even if it is not the issue, GET RID OF IT!

I agree with this statement. Even if not the problem now, these older model 7al3 Red boxes are the next problem waiting to happen in your ignition system imho.

I just installed a crank trigger and was using the pickup in my MSD distributer.....
I Still have an older red 7Al3.....Just have not gotten around to replacing it yet..
Just about 1 hr ago I fired it up and set the timing using the Crank trigger for the first time... 36 degrees dead on.....and the trigger signal is fed to a Grid Controller...

Swapped back to MSD dist pickup and timing was just under 35 degrees.....changed about 1 degree...

I wired it so if the crank trigger pickup fails I can plug the dist pickup right back in very quickly....

Either pickup starts easy as can be....no kickbacks.....timing solid....

Once we get out of this horrible Virus crisis the old red box is probably getting replaced.....

This message has been edited. Last edited by: SCDIV1,

Had similar horror stories to the OP's current situation, only about 5X more. Same engine combination, no crank trigger in my application. My issue turned out to be bad plug wires and old coil wires. I had two coil wires, coil was inside the car, with an isolator through the fire wall. The one inside the car was a problem cause i never changed it, just never thought about it. Now, i change plug wires on the regular, usually 1x per year. I experienced my problems with an MSD distributor, digital 7Plus, and with and without start retard. In my case there was no difference in with and without start retard.

Totally agree 139 tooth is the best stuff out there, but you'll still break starter clutches and gears. My problem was so bad that eventually i broke a crank 2/3 of the way around #1 rod journal. I was able to catch it before it broke completely, that was after 6 168 tooth flywheels and lord knows how many starters at one point i had a 5 gallon bucket full of mini starter parts and pieces.

A few things that have not been mentioned:
Make sure the heads are grounded to the block and the block grounded to the frame/battery.
Go to a larger distributor cap, if you are running the small one, move up to the largest diameter cap you can find and fit in your application.
Check all of the grounds in the car.
Don't forget to change/check the coil wire when you are checking and or changing plug wires.

As someone mentioned the spark is jumping to another cylinder in the distributor because its finding the path of least resistance, you just need to determine why that's happening.

I think it’s a lean kick back. Step on the gas peddle a little and see if giving it some extra fuel when your trying to start it works better if everything else checks out ok.
Good luck

I also recommend the large diameter cap and they also offer an adjustable rotor for it...

That's what I have....

Rotor is 2 piece and can be adjusted to line it up with cap properly....