Hi all,
I have a yamaha f15 with an unknown amount of hours. I picked it up with a RIB last year from a couple who had it on their 55ft trawler. It's been a great little outboard and seems to like to run. I use it daily to go to/from my boat. Previous owners did zero maintainance themselves on the outboard, have a giant pile of records from them. It appears they took good care of it, had oil changes done every 3 months since new(2016) throughout the spring/summer/fall. Every fall they took the engine in to have it "winterized" and every spring theyd bring it to the shop to have it "summerized" - IE the shop would tune it, change oils, slap new zincs in during spring and service the carb.
Since owning this OB since Jan of 2023, i've changed oil/filter 2 times(once in spring and once in fall).
I've noticed over the last 3 weeks or so, after letting her sit for a few hours(espically overnight), i get about 2-5 seconds period of time that really sounds like knocking. I can't point exactly where its happening, definitely near the head near the fuel pump. Somewhere in the back section of the engine IMO.
It was the second time I heard this, that i started wondering "hrm, thats not right", decided to do an oil change but everything looked fine/no milky oil. Nothing really obviously wrong.
I've noticed cold firings quite a bit more smoke at startup, smells like burning oil. When i say cold, i noticed this during winter - 30F-40F temps, figured it was a multitude of things being shes cold and excess fuel + oil on the walls accumulating and just burning off. Now that we are well into warmer temps, then temp isn't the cause, and smoke definitely something i'm continue watching. I wouldn't say it is a big concern as I still think it's oil on the walls since it doesn't stick around for long - give it 2 minutes or so and its gone.
So the biggest thing I'm concerned about is this knocking sound at startup. Today I took her out for a quick run at WOT since she hadn't been ran hard for a few months. Noticed after a few minutes of running she started to fall off on RPM, almost like lack of fuel(which i suspect). I put in a new external fuel filter that i've been battling an air leak - letting it sit for a few hours the bulb is completely empty and takes atleast 5 pulls to get her to startup.
Any ideas?
I have a yamaha f15 with an unknown amount of hours. I picked it up with a RIB last year from a couple who had it on their 55ft trawler. It's been a great little outboard and seems to like to run. I use it daily to go to/from my boat. Previous owners did zero maintainance themselves on the outboard, have a giant pile of records from them. It appears they took good care of it, had oil changes done every 3 months since new(2016) throughout the spring/summer/fall. Every fall they took the engine in to have it "winterized" and every spring theyd bring it to the shop to have it "summerized" - IE the shop would tune it, change oils, slap new zincs in during spring and service the carb.
Since owning this OB since Jan of 2023, i've changed oil/filter 2 times(once in spring and once in fall).
I've noticed over the last 3 weeks or so, after letting her sit for a few hours(espically overnight), i get about 2-5 seconds period of time that really sounds like knocking. I can't point exactly where its happening, definitely near the head near the fuel pump. Somewhere in the back section of the engine IMO.
It was the second time I heard this, that i started wondering "hrm, thats not right", decided to do an oil change but everything looked fine/no milky oil. Nothing really obviously wrong.
I've noticed cold firings quite a bit more smoke at startup, smells like burning oil. When i say cold, i noticed this during winter - 30F-40F temps, figured it was a multitude of things being shes cold and excess fuel + oil on the walls accumulating and just burning off. Now that we are well into warmer temps, then temp isn't the cause, and smoke definitely something i'm continue watching. I wouldn't say it is a big concern as I still think it's oil on the walls since it doesn't stick around for long - give it 2 minutes or so and its gone.
So the biggest thing I'm concerned about is this knocking sound at startup. Today I took her out for a quick run at WOT since she hadn't been ran hard for a few months. Noticed after a few minutes of running she started to fall off on RPM, almost like lack of fuel(which i suspect). I put in a new external fuel filter that i've been battling an air leak - letting it sit for a few hours the bulb is completely empty and takes atleast 5 pulls to get her to startup.
Any ideas?