Motor missing

[fishonnopeoff]

1999 Johnson 115ob missing. Seems to do it under power more than at idle (although I have heard it hiccup and cough) And the goofy thing is its not always there. At times it runs fine??

Changed the plugs cleaned gas filter.

I'm thinking wires or maybe CDI?

[Surface Tension]

When it does this have you squeezed to primer bulb, if so does it get better for a short time?

Could be a lot of things. You have to start the process of elimination.

Plugs and filter you've done. Next check all connections and lines on the fuel system.

Check to see if all the plug wires are seated. Some covers lathes will snag the plug wires and pull them off but not far enough to notice. Check all electrical connections and wires for opens or shorts. Your outboard will have a fitting for fogging and decarbing, check to see if its in the closed position. Check the compression.

Check the hose to the oil tank and make sure its not kinked. Over heating. look for a good water stream at the tell tale. This one might not sound related to the engine but check the lower unit oil level. If its low or water has intruded it'll create a lot of heat, friction and load.

Check the gas for water. Get the water to settle in the lowest part in the tank by jacking up the tongue jack all the way. Let it sit like that for a day. Through the filler, get a siphon hose to the lowest point in the gas tank and siphon into a clear gas jug. Water can show up as settled on the bottom or mixed in with the gas. If its mixed in it'll look swirly.

Anyway thats a start and something you can do yourself.

From there I'd go onto cleaning the carbs and rebuild the fuel pump.

[fishonnopeoff]

First off, thanks for the reply. Tried the primer bulb to no avail.

Just had it out again ran poorly all day long till the very end and then had no problem didn't miss a beat. I guess I will keep plugging away at it and see if I can figure it out....

[fish2live]

look and make sure your fuel lines are not dry rotted. i have a 99 honda that was running really bad out of the blue so i changed the plugs thinking this was it but while looking over the motor noticed all the fuel lines were cracking. must have been drawing air.

[iffy]

Do a compression test. It could be a seeping head gasket that lets water in one cylinder slowly or intermittingly.

[fishonnopeoff]

Thanks for the input I will try gas line and the compression test. Been kinda busy haven't had time to do much lately.