Erik Albin
New member
I have a early 90s 2/s 25hp merc that all of a sudden started backfiring after a long day out on the lake.
The motor ran fine all day long, but when I got into a canal i had to quickly change in and out of gear. During this process, the motor started to run at a high rpm when in neutral, and backfire, or pop. It was a high enough idle to where it made the motor shift hard. I small puff of smoke will come from the area of the carb. It seems to run fine in gear and I was able to easily get the boat back up to top speed once out of the canal. However, the boat still idles to high, and pops occasionally. I waited a couple of days, and ran it again and it seemed to be clearing itself up, with the popping or backfiring occurring less regularly. While it was running, I adjusted the idle level on the outboard throtle to raise the rpms. This brought back the issue right away.
I am wondering if the problem could be as simple as the cable from the throttle to the motor being loose, causing the motor to flood and pop? I would notice it did this one or twice in the past when running the boat at full throttle, and then reducing power quickly instead of easing off the throttle.
Other than that, I am assuming it could be the carb itself needing cleaning or rebuilding. Any suggestions?
The motor ran fine all day long, but when I got into a canal i had to quickly change in and out of gear. During this process, the motor started to run at a high rpm when in neutral, and backfire, or pop. It was a high enough idle to where it made the motor shift hard. I small puff of smoke will come from the area of the carb. It seems to run fine in gear and I was able to easily get the boat back up to top speed once out of the canal. However, the boat still idles to high, and pops occasionally. I waited a couple of days, and ran it again and it seemed to be clearing itself up, with the popping or backfiring occurring less regularly. While it was running, I adjusted the idle level on the outboard throtle to raise the rpms. This brought back the issue right away.
I am wondering if the problem could be as simple as the cable from the throttle to the motor being loose, causing the motor to flood and pop? I would notice it did this one or twice in the past when running the boat at full throttle, and then reducing power quickly instead of easing off the throttle.
Other than that, I am assuming it could be the carb itself needing cleaning or rebuilding. Any suggestions?