I have a 4 cylinder 40 hp 2 stroke Mercury 90s model. I have had issues in the past with cold starting and flooding after motor has warmed up and I try to restart after sitting for 30min to 1 hr. I pulled both carbs to check the float and make sure the needle seat was seating, found the float level a little off, but needle seat where fine. I found where someone had broke a small section power head casting just below the bottom carb, about the size of a dime, they had used some epoxy, it loosened up and the hole was exposed. I cleaned the area, and used some JB Weld marine epoxy, the piece of the casing was still there, I just epoxied it back in place. It seems to have sealed the area water/air tight, a decent repair.
Now, that I have done this, my outboard idles high, when I back the idle down to 1200 rpm are lower, I get a "popping" from the top section of the power head around the flywheel, one here and there, might be 20 secs before another, or 2 mins to the next.
I adjusted both carbs, turn the mixture screw in until it started to stumble and out 1 to 1 1/4 to 1 1/2 and still get the popping ever now and then, with each the the adjustments.
Pulled a compression test, 140+ and every cylinder +/- 3 psi.
It never popped like this before the hole repair, and float adjustment, use a caliper to set float.
The popping is only at lower RPMs, hit 1500+ and not a single pop.
What should I try next?
Thanks for the help, I appreciate it greatly.
Now, that I have done this, my outboard idles high, when I back the idle down to 1200 rpm are lower, I get a "popping" from the top section of the power head around the flywheel, one here and there, might be 20 secs before another, or 2 mins to the next.
I adjusted both carbs, turn the mixture screw in until it started to stumble and out 1 to 1 1/4 to 1 1/2 and still get the popping ever now and then, with each the the adjustments.
Pulled a compression test, 140+ and every cylinder +/- 3 psi.
It never popped like this before the hole repair, and float adjustment, use a caliper to set float.
The popping is only at lower RPMs, hit 1500+ and not a single pop.
What should I try next?
Thanks for the help, I appreciate it greatly.