I have a 180 (basically same motor as a 470) I rebuilt a few years back. The motor was tight with a cold compression of 152 psig on 4 clicks when fresh. I had an episode with the wrong float supplied in the carb that was flooding out the carburetor and intake enough to kill the motor, in addition to a bad coil with 8 hours on it. Long and short of it is I got it running again and it runs like a champ. I did notice after a longer run the breather by the flame arrestor was smoking when the engine was shut down after a prolonged high speed run. When home, I ended up pulling the oil fill cap at idle and idled the boat on muffs. It felt like it had a good amount of puffing, but when I put a piece of paper over the cover it barely fluttered. The fluttering/pressure wave pretty much disappears when I run it up to 1500 rpm and up, but at idle it feels like it is breathing heavy. I am burning no oil and don't know what else could be doing this. Compression on a warm engine is 140 psig on all 4 cylinders.
I suppose it is possible I overlooked this on the rebuild, but does anyone else with a 470 have a similar observation? Thanks in advance for any insight into this.
Ron
I suppose it is possible I overlooked this on the rebuild, but does anyone else with a 470 have a similar observation? Thanks in advance for any insight into this.
Ron
