Stepney 2,314 #1 Posted May 30, 2017 Hello, all. Well I've had two really neat finds lately.. but that's for another time. One of those machines is a 1970 Simplicity 728 Broadmoor with a vertical 8hp Briggs, generator start.. odd duck. Anyway, she runs incredibly well and so far everything seems to work.. except one thing. This doesn't even have a dip stick, just the oil fill cap which you fill to the top. And it's at the top, level is fine. When running anything over idle, the engine is clean with no smoke, but if you idle it, it absolutely starts pouring blue smoke, until you speed it up again.. then it goes away almost immediately. I've never seen that before.. any ideas, anyone? Share this post Link to post Share on other sites
W9JAB 156 #2 Posted May 30, 2017 Well blue smoke would be oil, and at a low rpm it's pumping oil, them clears up at hi rpm, my guess is a piston ring may be collapsing or staying compressed at low rpm. Share this post Link to post Share on other sites
oldredrider 2,547 #3 Posted May 30, 2017 Check for a semi-clogged breather. At low rpm, crank case pressure may be moving past the rings taking oil with it to the top of the cylinder. Share this post Link to post Share on other sites
slammer302 2,154 #4 Posted May 30, 2017 I have a engine that does the same thing it's just worn out but runs great and it's been this way for going on 10years adding sum Lucas heavy duty oil stabilizer does help. Keep an eye on it spark plugs they will go bad faster with higher levels of oil burning. Share this post Link to post Share on other sites
W9JAB 156 #5 Posted May 31, 2017 I was thinking about this and I remembered some thing about Ohan's, The same motor was used for vertical and horizontal shaft. But when used as vertical there was some mod. to the oil pan or fill tube, I do not have time to research it now, but I'm thinking an oil overfill may be the problem. Share this post Link to post Share on other sites
Stepney 2,314 #6 Posted June 5, 2017 On 5/31/2017 at 10:55 AM, W9JAB said: I was thinking about this and I remembered some thing about Ohan's, The same motor was used for vertical and horizontal shaft. But when used as vertical there was some mod. to the oil pan or fill tube, I do not have time to research it now, but I'm thinking an oil overfill may be the problem. I have no idea honestly. I've had at least 20 Briggs verticals just like this one, they're all the same.. just take the plug out and fill until it overflows. (Well.. it's foolproof?) I'll pull the breather off some time.. but it's probably just tired. Too bad, I've had far worse machines that never smoked. Share this post Link to post Share on other sites