Engine Missing

[Hydro-Thunder]

Ok chime in with your opinions. I was running my BBF and all of the sudden it started to studder pretty bad. I was not on it hard when it happened and no noise. What wound be the first things to check?
Jesse

[Blown 472]

what kind of ignition do you have? plug wire fall off, you look at the plugs?

[Hydro-Thunder]

MSD plugs look ok wires are ok. Can the MSD act like that? I was thinking next step is check out MSD then check valve springs, comp, leak down? Am I on the right track?
Jesse

[Blown 472]

I would double check all of your electrical connections, my buddy had a bad ground on his msd and made it miss like crazy, if they are good can you swap it for another just to try??

[Hydro-Thunder]

I could run with out msd and check but I dont have another.

[Blown 472]

I would try that, does it crank like it has a dead hole??? meaning when you crank it with the ignition of does it have and even sound to it or does it speed up for a second and then sound the same after?? you look at the plugs to make sure they are ok?

[Hydro-Thunder]

Cranks fine no dead spots. I will have to double check the plugs.

[Blown 472]

What dist do you have?? what rpm did this happen at?? you check your fuel pump?

[LakesOnly]

Here are some really easy micky-mouse things to do:
A simple test would be to start pulling plug wires one at a time while the engine is idling. See if you come accross any cylinders that dont' affect running when the plug wire is pulled. A functioning cylinder that has the plug wire pulled will create a drop in idle; but a dead cylinder that has a plug wire pulled with have no effect on idle.
Don't wanna risk getting shocked? Hook a timing light to each plug wire and pull the trigger...do you have an ignition pulse on each plug wire? If so, look at your plugs. (You should probably not look at only the plug of a bad cylinder but rather read all plugs for any sign of trouble.) Plugs ok? Go to a compresson test.
LO

[gnarley]

Don't overlook fuel, quality or quantity. A little water in the mix will do that also ;) If it was fine before I would look into the fuel side unless something was disturbed in the ignition side just prior to this last outing.

[Mopar426]

I would look at the distributor cap for moisture. I have had a similar problem with condensation build up in the cap when running on cold or very humid days. The heat in the cap reacts with the moist cool air and all hell breaks loose. A little WD-40 seemed to cure the problem. Just a suggestion.

[mickeyfinn]

This is probably a long shot but I had it happen to me one time. What kind of intake are you running? I had a Torquer intake with bolt holes for a spread bore and for a quadrajunk. When running a holley one of the holes for the quadrajunk is about 25% uncovered. Ordinarily this is not a problem but somehow the bottom of that particular bolt hole was gone allowing the engine to suck air from the open bolt hole. Fix was quick, a set screw coated with J/B weld turned into the hole and no more problem. Spent a lot of time chasing the problem though as the opening in the bottom of the bolt hole was only visible when looking through the intake at the proper angle with the carb off. Easiest way to test this is to let the boat idle and pour some water around the edge of the caburator base plate. Like I said it is a longsho but might worth looking at. Doesn't cost anything to pour some water around the carb while idling.