Southerncannuck 73 #1 Posted November 17, 2016 (edited) My C-125 runs great and performs it's tug duties admirably. Long may it live! But I'm curious about something. It does smoke quite a bit a few seconds after start up and does so for about 30 seconds then for the most part stops. Where could this oil be coming from? I thought that these engines (K301) were splash lubricated and the valves sure don't seem to be in a place where they would drip into the combustion chamber upon shut down. What am I missing? If the rings were shot wouldn't it be smoking all the time? Edited November 17, 2016 by Southerncannuck Share this post Link to post Share on other sites
Achto 29,408 #2 Posted November 17, 2016 2 minutes ago, Southerncannuck said: It does smoke quite a bit a few seconds after start up and does so for about 30 seconds then for the most part stops. Is it a black or a blue smoke? Share this post Link to post Share on other sites
Southerncannuck 73 #3 Posted November 17, 2016 1 minute ago, achto said: Is it a black or a blue smoke? It's blue. Smells oily. Share this post Link to post Share on other sites
Achto 29,408 #4 Posted November 17, 2016 Strange indeed. Like you said oil should not be able to get past the valves while sitting. I wonder if the rings are a little sticky and it's taking a bit for them to expand & seal? This is not always easy, but if you can see the top of the piston. Look to see if it is carbon covered or if it is clean around the outside edges. If there are clean areas around the edges then you have bad rings. If the whole top of the piston is carbon covered then the rings are sealing as they should Share this post Link to post Share on other sites
Southerncannuck 73 #5 Posted November 17, 2016 (edited) What is your opinion on running the engine for 20 minutes or so before the next oil change with a pint of Marvel Mystery Oil in it? Might that help if it turns out to be stuck rings? I don't know this engine's maintenance history but I doubt it was as loved as it is now. Edited November 17, 2016 by Southerncannuck Share this post Link to post Share on other sites
Elkskin's mower junkyard 1,117 #6 Posted November 17, 2016 5 minutes ago, Southerncannuck said: What is your opinion on running the engine for 20 minutes or so before the next oil change with a pint of Marvel Mystery Oil in it? Might that help if it turns out to be stuck rings? I don't know this engine's maintenance history but I doubt it was as loved as it is now. imo just run her. sooner or later they will be fine if they are stuck. majority of my tractors smoke. the ones that smoke heavily get off brand oil others are name brand Share this post Link to post Share on other sites
Achto 29,408 #7 Posted November 17, 2016 (edited) 3 hours ago, Southerncannuck said: What is your opinion on running the engine for 20 minutes or so before the next oil change with a pint of Marvel Mystery Oil in it? This has worked for others in the past. I would not be afraid to try it. You are talking about bleeding a pt of the old oil off then adding back to the full mark with Mavel ? Correct? Edited November 17, 2016 by achto Share this post Link to post Share on other sites
stevasaurus 23,285 #8 Posted November 17, 2016 Here is a picture of what Achto is talking about with bad rings. Here you can see the clean area from 12:00 to about 5:00...bad rings. 3 Share this post Link to post Share on other sites
Achto 29,408 #9 Posted November 17, 2016 Great pic Steve! Perfect example of what most call "piston wash", caused by bad rings. 1 Share this post Link to post Share on other sites
roadapples 6,983 #10 Posted November 17, 2016 If the breather behind the carburetor needs cleaned it will cause some smoking... Share this post Link to post Share on other sites
Southerncannuck 73 #11 Posted November 17, 2016 Thanks everyone, that gives me a good starting point. I've been meaning to yank the head off to peek inside anyway. Share this post Link to post Share on other sites
