|Definitely a Knock (Graymarine 109)...
Post Number: 41
|Posted on Tuesday, October 16, 2018 - 09:04 am: ||
We have a knock....
here is a link to the video....hopefully this one will work better than before: Try copying and pasting if a clickable link doesnt show up.
My dad took the head off and found this on the #1 cylinder.
We always felt like we had a knock, but thought it was just ignition knock. So we adjusted the timing at 3/4 throttle and got most of that, if not all of that out. Then I moved onto the carb to try and tune it in at 3/4 speed. Thats when the knocking started REALLY REALLY BAD like in the video.
So we pulled the engine and are looking into to having it machined and re-sleeved. Has anyone ever had to do this to a 109 or similar engine? Just curious what to look for. If we bore it out, do we need to bore out all cylinders or just the one? Any advice is appreciated.
Post Number: 1394
|Posted on Tuesday, October 16, 2018 - 07:38 pm: ||
You won't know about the cylinders until it is disassembled and measured. I would suspect rod bearing problems, probably Babbitt bearings, crank would have to be ground and bearings re poured.
Post Number: 180
|Posted on Sunday, October 21, 2018 - 11:07 pm: ||
I donít see why just that one cylinder couldnít be sleeved. Maybe you will be lucky and it is just that one wrist pin that is bad and making all that noise. It sure did a job on that cylinder.
(I have a Stover. CT2 stationary engine with similar damage, but on that engine there is just a set screw that holds the wrist pin in place and keeps it from scoring the cylinder (or not if that set screw comes loose.)