The first time I took it out it had a bad backfiring problem at idle and on throttle but only on the passenger side, messed around with the carb and distributor while driving with no luck, loosened a couple rockers and it stopped popping on idle but still on throttle.
Re adjusted all the roller rockers on the passenger side while running on trailer and all popping stopped. Got it into the water and runs great up till 2500rpm and then goes back to backfiring
Any ideas where to look? Figured somewhere in the heads maybe sticky lifter or bad springs?

I would start by looking at the plugs and wires like mash on it said...and if nothing there to be found start pulling the wire off of one plug at a time on the side to find the cylinder that has the problem...on a 79 Pioneer that we had started doing the same thing and it ended up being the cam because the valves were adjust wrong and flatten the cam

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Is there any chance your plug wires are cross firing? It sounds silly I know but I’ve had it happen before.

Take some zip ties and make sure they are nicely separated and not laying on each other.


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He could be on to something here. Or something along those lines. I remember with my v-drive we changed the oil, changed spark plugs and rebuilt carbs................took it out the next time and it would back fire everytime I would try to accelerate. Over and over, super embarrassing. Lots of ford jokes. When we put the wires back on we crossed two of the spark plug wires on the wrong plug. Ruined my whole boating weekend. Simple ass dumb fix and I was back on the water the following weekend. Maybe this can help

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