[cookiedoh]

I have a 1989 v4 115hp yamaha outboard. It was running a little rough below 2000rpm and seemed like it was smoking a bit too much. I turned the pilot screws in (leaning) adjusted the idle set screw on carbs to 800rpm (using dash guage, I know I need to get a more accurate one) timing was at about 2*ATDC, book said 4-6 so I moved it out. Ran great for on the first and second run, real smooth at all RPM. Third time out, stalls at idle, stalls at low rpm, and runs with a cough at idle. RPM's erratic at idle, runs at 900 for 3-5 seconds, coughs and drops to like 300rpm, stays down there for a little while then slowly works back up to 900. I tried putting the pilot screws back, re-checked timing, didn't seem to make any difference.

Fouled carbs, plugs, coil, compression...something I'm not thinking of? Point me in a direction? Thanks.

[cookiedoh]

Are pilot screws usually adjusted to the same number of turns or is it specific to each cylinder?

[JUSTINTIME]

i would rebuild those carbs and fuel pump