F115 at idle does it sound ok?

[ChuckieP3]

hello everyone I’m looking at a 2018 yamaha f115 with 100 hrs. Ran well on sea trial but at idle I thought it sounded off, would you mind sharing your opinions of short sound clip, thanks again, Chuck
https://m.youtube.com/watch?v=FTkyZ0G-J4A

[brian3006]

My F115 seems to idle differently than my f90's do. It seems to be a lower and slightly rougher idle if that makes sense. If it starts and runs well at WOT and throughout the rpm range, it would probably be fine. See if you can take a look at the cylinder compression. that will tell you a lot. Also, give you a chance(albeit limited) to look inside the spark plug hole at the cylinder condition. also might be worth bringing your own fresh gas and hooking it up to that if you are unsure of the gas quality in the boat now.

Believe it or not, I once blew a 115 and did not know it until the oil alarm went off. put a nickel size hole in the top of one of the pistons and ran for over 5 miles without even knowing it. I even shut it down to investigate the alarm and then started it back up and idles another mile or so back in. The computers on these things are amazing for being able to compensate for a problem somewhere, but at the same time allow for the smallest thing to throw it all out of wack

[ChuckieP3]

Thanks Brian, did do a compression test after pulling boat, that ranged 190-200psi, also looked at a small sample of lower unit lube which looked clean. Plugs looked fine and equal wear. Oil level was good and appeared fresh. Tech hooked it up to computer after pulling out of water and no codes had thrown but he didn’t hear motor running. Not sure what to think. All my wrench head buddies say the motor sounds bad in the video, so now I don’t whether go further with is sale or not

[brian3006]

Hmm well you definitely did your diligence in checking out the engine and by all of those factors, it looks good. However, I will say that I agree that it does sound like there is a slight tic to the engine. That being said I am pretty sure my 115 sounds similar as well. I find myself bumping mine up to idle at 800-900 rpm or so sometimes just because it is smoother and sounds better...

you said the oil appeared fresh... as in just changed??? I am sometimes suspicious if I look at an engine and it has brand-new oil in it. makes me wonder if they are trying to hide a problem.... or did they just change it trying to solve a problem that it didn't...and thats why it is for sale.... But that is just me

[ChuckieP3]

I was suspicious of that as well.