'78 85hpp rude. Miss can't find

[fireman57]

Engine was totally submerged for 36 hours. Got it home and cleared everything out. Not the first time I have had to resurrect one. Compression 120 all four cylinders. All the grounds had corroded off so replaced all of them. Cleared all fuel lines and blew out carbs.Took starter apart and cleaned it. New solenoid and had to replace a powerpack and put new Champion plugs in. Fuel pump was cleared and is okay. Spark jumps a good 7/16th inch and bright blue.
Got her fired up and there is a miss in there somewhere I can't find. Bottom carb was leaking and I could not get it to seal so got a kit and rebuilt the whole thing. Welch plugs and all. Blew out with compressor like always. Fired right up and ran nice. It was idling faster on the muffs than before and no shaking so I thought I had it.. Shut it off and called the missus out to hear it and when I fired it up again it had the miss and the shake again.
Engine was not running when it sunk and both carbs suck air good, nothing in the reed valves, and all fresh fuel. Carb bowls are both full.What the heck am I missing?

 

[gm280]

What about water intrusion into the stator and spark coils? Hard to bring up a sunken engine and not have the electronics effected. And coils and such will certainly have water problems. And what about the timer base assembly as well. With corroded grounds, I would suspect ever wire on the engine until I could prove them good otherwise. Water can easily wick up under the wire insulation and rick havoc. JMHO

 

[fireman57]

I had four new coils in my shop so changed all them, also have great spark on all so I really can't suspect timer base an such.

 

[gm280]

fireman57, when it does the miss-firing, can you detect if it is from all cylinders or to just one or more? If it is from all cylinders, then it has to be something that feeds all cylinders. If it is from one or two, maybe the carb for those cylinders still needs attention. You have to eliminate things when trouble-shooting. And then what is left, is the culprit. JMHO

 

[interalian]

I'd try a timing light on each spark lead in turn, looking for dark spots in the flash.

 

[fireman57]

Ran great after another carb cleaning following the rebuild. Screamed for about 4 hours and then fell to half speed. It is super humid here right now so I am getting the blue gunk in the carb throats but that is normal. Timing light shows good spark. When you throttle up it takes off nice and smooth but won't get to the next level like the high speed jets aren't kicking in. Carbs are actually spotless. When I replaced the welch/frost plugs it was even clean in there. About to pull the last few hairs I have out of my head.

 

[fireman57]

Spark tester shows blue spark jumping over 1/2 inch. Reeds look fine.