yamaha 1999 225ox66 outboard wont start

[misslisa11]

changed all filters in my 225ox66 changed the three fuel pumps on the side of motor ,changed plugs ,water separator ,i did all of this because i bought boat used and didn't know when any maintaince was done . also the motor would die at WOT.I was also having trouble starting . the motor ran well for a month . the boat sat on trailer for a month , when I went to use itv last week it wouldn't start .seemed like it wasn't getting any fuel .primer ball was hard as a rock. matter of fact i squeezed it so hard it separated from the hose a little . took it to local mech. got it running yesterday and today he calls and tells me # 6 cylinder isn't firing ??? .waiting for phone to ring with bad news . any ideas

thank you

[TownsendsFJR1300]

One cylinder not firing could be a bad ground, bad coil, etc, nothing near as bad as low compression... I suspect he'll check (if not already) the compression.

One cylinder not firing likely would not cause NON-starting issues nor dying completely at WOT.


Sounds like your issues are fuel system related..


Are you using ethanol fuel and if so, treated and how old is the fuel? If adding fuel to old (especially ethanol) fuel isn't good. Ethanol goes bad as quickly as a month.
Added to old bad fuel = more bad fuel, clogged carburetors, etc..

[DennisG01]

Would 2 cylinders not firing cause a no-start issue? The reason I say that is because cylinder 5 is not active at idle... but I don't know if it is active during the starting procedure and then the computer deactivates it after the engine starts, or not?