97 mariner mag efi 150 og486771. Been having this problem since last year, starts up fine off the trailer(sometimes have to crack open the throttle some depending on the day) idles fine jumps up on plane and will top out at 51mph good. Was having an issue getting started back up after a run if I didn't fish at least an hour in warm weather, was this way all spring-fall.
Things I did: replaced spin on fuel filter, fuel line/primer bulb, below deck fuel line, anti siphon valve, spark plugs (all looked good), both voltage regulators(tach wasn't working), thermostats and rebuilt poppet valve.
Starting problem still exists although every once in awhile it won't give me trouble but it seems to be more often than not. Back in October when the water was still above 60* it developed a bad hesitation at wot only, would run just fine if I backed off to about 3/4 throttle. Was off the water the rest of the year until last week(water temp 41*), boat fired up and ran great for about 5 miles and then it randomly had a quick single hesitation. Happened fast enough to notice but not lose speed. A minute or so later it did it again this time in a couple short quick bursts and then it was fine. I had planned on rebuilding the fuel pump but since it's not necessarily a consistent issue I'm not so sure I'm looking in the right direction. Also when it gives me issues getting started back up when I hit the key it will fire once and die instantly. I've learned it is consistent that if I crack the throttle about 1/4 and ease out for a few seconds it will stay running(idles like crap for a few and then all is well but still gets up and goes good) any suggestions would be appreciated
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Originally Posted by Sheps78
