98BassTracker
New member
Hi everyone, I have a 98 Mercury outboard 40hp 2 stroke that comes on the bass trackers. This motor just started surging rpm’s and has a hard time cranking almost feels like bad gas but I know it isn’t. It done the same thing last year, I would give it full throttle and it would struggle to get up to all out and would then cut back and forth and jump down 1k rpm and jump back up and work it’s way until you can’t even idle it anymore. I took it to a boat mechanic shop and they replaced every seal, all fuel lines, carburetor, fuel filter, fixed the timing, and none of this fixed it, it finally was fixed by replacing the stater and trigger. Since I got it back about 8 months ago I’ve driven it close to 100 hours and haven’t had a single problem out of the motor and it’s run perfect. This week both times I’ve took it out, it ran perfect for the first 20-40 minutes and would start surging which automatically put me down to 25 mph when it normally goes 32-34, and continues to work it’s way down until you can’t even idle it and it shuts itself off and won’t crank. I have a hard time believing the stater and trigger is bad again, I’ve checked compression and it’s perfect, I’ve checked all fuel lines and none are clogged or leaking, cleaned out carburetor and it’s still doing it. Hate to take it to a boat shop and have to leave it for more than 2 months when it’s prime river time now. I will also say this motor had less than 50 hours before I took it to get everything fixed last year. My dad only took it out 3 times and the relative we bought it from had took it out 5 times. So it has sat up for 20 years but as mentioned has run perfect for the last 8 months and I’ve put around 100 hours on it. Any help or insight would be greatly appreciated.