darlington_john
Member
"I just purchased a boat that
"I just purchased a boat that came with a 2001 125 ELPTO Saltwater Series Mercury. Before I purchased it we just fired it up in the previous owners driveway and it sounded fine. However when we took it out today in the water today, actually as soon as we fired it up, there was a fairly loud knocking sound. We took the boat out and it ran fine...WOT it performed excellent. My friend stated that his buddies 115 Merc also made similar sounds but I've owned over 15 2-stroke outboards and I've never heard knocking like that.
When we removed the cowl, the knock seems to come from the powerhead so could this be piston slap or a bad crank? The engine doesn't smoke any more than usual and runs great through the entire power band. It also starts fairly easily so am I over-reacting or could this be something significant?
One last thing - the previous owner also stated that the engine shut down last year at WOT and would not start back up. They ran in shore with the kicker, removed the plugs, cleaned them, and then it fired back up and they went back along their merry way. The boat has since been winterized and also serviced last week by the same dealer that has always worked on this boat. They changed out the impeller and also did a compression check which measured 115-115-120-115 which is normal. They also had the outboard running for over 5 minutes (on muffs) and never noticed any issues. The sound cannot be heard with muffs since the outboard is loud but then again once the engine is in the water the knock is quite loud."
"I just purchased a boat that came with a 2001 125 ELPTO Saltwater Series Mercury. Before I purchased it we just fired it up in the previous owners driveway and it sounded fine. However when we took it out today in the water today, actually as soon as we fired it up, there was a fairly loud knocking sound. We took the boat out and it ran fine...WOT it performed excellent. My friend stated that his buddies 115 Merc also made similar sounds but I've owned over 15 2-stroke outboards and I've never heard knocking like that.
When we removed the cowl, the knock seems to come from the powerhead so could this be piston slap or a bad crank? The engine doesn't smoke any more than usual and runs great through the entire power band. It also starts fairly easily so am I over-reacting or could this be something significant?
One last thing - the previous owner also stated that the engine shut down last year at WOT and would not start back up. They ran in shore with the kicker, removed the plugs, cleaned them, and then it fired back up and they went back along their merry way. The boat has since been winterized and also serviced last week by the same dealer that has always worked on this boat. They changed out the impeller and also did a compression check which measured 115-115-120-115 which is normal. They also had the outboard running for over 5 minutes (on muffs) and never noticed any issues. The sound cannot be heard with muffs since the outboard is loud but then again once the engine is in the water the knock is quite loud."