AMC backfiring

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   It doesn't matter where the rotor is pointing. It is important that the corresponding lead on the cap is connected to #1. Then continue the firing order from there. I would consider pulling all the leads and starting from scratch.

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Lucas660 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Apr/16/2012 Location: Vic, Australia Status: Offline Points: 1344	Post Options Post Reply Quote Lucas660 Report Post Thanks(0) Quote Reply Posted: Jul/17/2018 at 5:42pm
	It doesn't matter where the rotor is pointing. It is important that the corresponding lead on the cap is connected to #1. Then continue the firing order from there. I would consider pulling all the leads and starting from scratch.

vinny Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jan/05/2012 Location: Calgary Status: Offline Points: 2837	Post Options Post Reply Quote vinny Report Post Thanks(0) Quote Reply Posted: Jul/17/2018 at 6:27pm
	As above. Have you checked that there are no vacuum leaks?

AMC-304 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/08/2018 Location: Star, Idaho Status: Offline Points: 40	Post Options Post Reply Quote AMC-304 Report Post Thanks(0) Quote Reply Posted: Jul/18/2018 at 9:49am
	Ok,do i need to get another coil for this hei? the spark is white not blue.....

vinny Members Profile Send Private Message Find Members Posts Add to Buddy List Supporter of TheAMCForum Joined: Jan/05/2012 Location: Calgary Status: Offline Points: 2837	Post Options Post Reply Quote vinny Report Post Thanks(0) Quote Reply Posted: Jul/18/2018 at 10:59am
	It's probably OK. Maybe at night it will be blue. What kind of a gap will it jump? No cracks in the cap or carbon tracking? It is easier to see that kind of leakage at night too. Take a close look at the rotor too and that carbon piece in the cap. You could buy one of those spark testers and try it at the end of every plug wire. Can you confirm from the impeller which way the engine is supposed to turn? I don't know much about boats. Like the others I still think it could be a firing order or timing issue although you've dispelled the opposite rotation issue. Edited by vinny - Jul/18/2018 at 1:54pm

a401classic Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: May/02/2008 Location: GA Status: Offline Points: 98	Post Options Post Reply Quote a401classic Report Post Thanks(0) Quote Reply Posted: Jul/19/2018 at 1:26am
	I had a 1976 Saguaro 18' boat with a 401 and a Berkeley 12JCA jet drive. I picked it up in 1986 and dismantled it in 2006 - who knew formosan termites would build a tunnel from the yard, up the tires and into the boat? Apparently they love marine grade plywood. I was told it had a 304 when I bought it. I ran it 10 years before rebuilding it. Mine was standard rotation. The biggest problem I had was oil. I could run for about 5 minutes and the pressure started to drop. I'd let it idle for 5 minutes and repeated the process - at 4000 rpm continuous all the oil ends up in the heads. Its easy to be 180 out on the distributor, its also easy to be off one cylinder. Both will have you backfiring in no time. Mine originally had a nylon timing set (cam sprocket) and there were a few teeth missing when I took it apart. I also found out that it was a 401 not a 304, I think that's when I found this forum. I kept the original distributor but put in a Pertronix unit and never looked back - the points and condenser were problematic on the water. As others have said, either timing (misaligned distributor) or stuck valve will give you backfire issues. So pull the dist, take the wires off the cap, find TDC on the compression stroke, reinstall the dist and put a mark on the base of the dist where the cap sits that you can see when the cap is on that shows the rotor position. If it doesn't line up with a terminal, pull the dist, rotate the rotor accordingly and reinstall so that the rotor tip aligns with a spark plug terminal - That's #1. Then run your wires one at a time 1-8-4-3-6-5-7-2. Also run a quick compression check on all 8 - without fresh oil in the rings, your numbers will be low, but a stuck valve will either have no pressure or drop like a rock. I also built a custom stainless 8 qt oil pan and still had oil issues, but it would last 10 minutes before the pressure started to drop. What year and make is yours? If the boat is new to you, I'd rebuild it and probably the pump, too. Sand is your worst enemy - it will eat the wear ring in no time, then the impeller rattles, a lot. If you have a Berkeley Jet, I've got the socket that fits the nut on the end of the shaft - let me know and I'll donate it to the cause. Best of luck! Scott Edited by a401classic - Jul/19/2018 at 5:20am
	'64 Rambler Classic 770 2DR Twin Turbo 423.7 AMC (short block done) TH400 / GV

Boris Badanov Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Addicted Joined: Dec/14/2013 Location: NH USA Status: Offline Points: 4209	Post Options Post Reply Quote Boris Badanov Report Post Thanks(0) Quote Reply Posted: Jul/19/2018 at 11:18am
	Modern AMC V8's tend to collect all the oil in the valve covers at high engine speeds. But that does not sound like your issue. Oil temp seems to be the issue :-)
	Gremlin Dreams

AMC-304 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/08/2018 Location: Star, Idaho Status: Offline Points: 40	Post Options Post Reply Quote AMC-304 Report Post Thanks(0) Quote Reply Posted: Jul/19/2018 at 11:45am
	Well if it would start i can see oil temp as an issue...i just need to get it running first. Hopefully this weekend...

AMC-304 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/08/2018 Location: Star, Idaho Status: Offline Points: 40	Post Options Post Reply Quote AMC-304 Report Post Thanks(0) Quote Reply Posted: Jul/22/2018 at 7:40pm
	Scott, please explain the dist. Install because if you mark it, you can turn the dist. to match the rotor...

a401classic Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: May/02/2008 Location: GA Status: Offline Points: 98	Post Options Post Reply Quote a401classic Report Post Thanks(0) Quote Reply Posted: Jul/22/2018 at 8:38pm
	I only had so much room to rotate the distributor because the vacuum advance housing would bump into one bracket or another, so in order to have room to adjust the advance once it was installed I pretty had to nail it +/- one tooth. If you've got room to rotate the dist to align on a terminal, go for it. The point is: make sure #1 is really #1. Scott
	'64 Rambler Classic 770 2DR Twin Turbo 423.7 AMC (short block done) TH400 / GV

AMC-304 Members Profile Send Private Message Find Members Posts Add to Buddy List AMC Apprentice Joined: Jul/08/2018 Location: Star, Idaho Status: Offline Points: 40	Post Options Post Reply Quote AMC-304 Report Post Thanks(0) Quote Reply Posted: Jul/22/2018 at 10:17pm
	So Scott, something weird happened tonite, i thought i would check the comp. Stroke on # 1 cylinder, i went to tdc on comp and the rotor was pointing up like it was 180 out, so i thought thats it...so i thought lets check it again, did it again on comp and it pointed to the rear, tried it again and it pointed to the front...blew my mind!!!! so my question is maybe gear on the dist????? No the gear on the dist is tight...my mind is blown!!! Edited by AMC-304 - Jul/22/2018 at 10:51pm