Right at the end of last season my Yanmar 3GM began to act up when starting. Basically I had to crank it for a long time (5 x 30 seconds) to get it going. While cranking white smoke was coming out of the exhaust. Once started it seemed pretty normal. Prior to this it has always started immediately. The only things I can think of are a) something broke or b) the weather was colder and the oil too heavy (I don't actually know what the weight of oil was in it as I did not change it last and its not in the log) I am concerned when we launch I may not be able to start it at all! Thoughts, suggestions, ... Jeff
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joe phibbs
quick question?
Isn't white smoke water condensation? If it is, then that smoke might be seawater aspirated by cranking the engine and water sucked back thru the exhaust into the piston. We have a 2GM20F and procedure for cold start is to close the raw water intake then crank a while with cutoff pulled out, then try to start engine. You will get a dozen folks telling you to check the Mixing U, etc. They are right.
Isn't white smoke water condensation? If it is, then that smoke might be seawater aspirated by cranking the engine and water sucked back thru the exhaust into the piston. We have a 2GM20F and procedure for cold start is to close the raw water intake then crank a while with cutoff pulled out, then try to start engine. You will get a dozen folks telling you to check the Mixing U, etc. They are right.
Have a Yanmar mechanic check it out.
Jeff: I would contact a Yanmar mechanic. This would be a head gasket. White smoke is not good, I would have it checked out before anything gets worse.
Jeff: I would contact a Yanmar mechanic. This would be a head gasket. White smoke is not good, I would have it checked out before anything gets worse.
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Bill O'Donovan
Warning
Keep the raw water intake value off until you get ignition. Otherwise you'll flood the engine and exhaust with water, creating a new problem.
Keep the raw water intake value off until you get ignition. Otherwise you'll flood the engine and exhaust with water, creating a new problem.
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Gary Wyngarden
White Smoke
Jeff, Just went through this with my Yanmar 3gm30F. We'd get white smoke on starting and a small fuel slick on the water and slow to start. This gradually got worse, and I consulted a mechanic. He also discovered a significant amount of crankcase pressure out the breather. Both are symptoms of piston ring seating problems. We proceeded to do temperature tests on each cylinder as well as compression tests and found significant problems with two of the three cylinders. This really upset me as the engine only had 1800 hours and has been very well taken care of by me as long as I've owned the boat. As has been suggested, I'd get to a qualified mechanic ASAP. Gary Wyngarden S/V Shibumi H335
Jeff, Just went through this with my Yanmar 3gm30F. We'd get white smoke on starting and a small fuel slick on the water and slow to start. This gradually got worse, and I consulted a mechanic. He also discovered a significant amount of crankcase pressure out the breather. Both are symptoms of piston ring seating problems. We proceeded to do temperature tests on each cylinder as well as compression tests and found significant problems with two of the three cylinders. This really upset me as the engine only had 1800 hours and has been very well taken care of by me as long as I've owned the boat. As has been suggested, I'd get to a qualified mechanic ASAP. Gary Wyngarden S/V Shibumi H335
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R. Young
Check the Idle
Possible the idle is set too low. This is a mechanical setting so it can eventually slip. At low idle, you will experience the symptoms you describe i.e., cranking and because of little pumping action, superheated exhaust because of little mixing with water yields white smoke. Quick check would be to notch up the rpm just a tad on startup. If that works then check the idle mechanical setting and RPM against specs. R. Young Hunter 37
Possible the idle is set too low. This is a mechanical setting so it can eventually slip. At low idle, you will experience the symptoms you describe i.e., cranking and because of little pumping action, superheated exhaust because of little mixing with water yields white smoke. Quick check would be to notch up the rpm just a tad on startup. If that works then check the idle mechanical setting and RPM against specs. R. Young Hunter 37
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Paul Akers
Think back...
...to what type of maintenance was done to the engine just before the problem started. Did you change the filters? Make any adjustments? White smoke and loss of power while running means air in the fuel lines. Just a thought.
...to what type of maintenance was done to the engine just before the problem started. Did you change the filters? Make any adjustments? White smoke and loss of power while running means air in the fuel lines. Just a thought.
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Tim McCarty
Had similar problems with my 2GM
Check the archives...there is a plethora of info. on starting problems with the Yanmars. I still have problems with cold starting, BUT, once the engine starts, it sounds fine. This spring, when I can hook up a water supply...I will go through my checklist...checking filters, bleeding the fuel line etc... By the way, interesting cold start technique...I'd like to check this out further...let me grab my service manual...
Check the archives...there is a plethora of info. on starting problems with the Yanmars. I still have problems with cold starting, BUT, once the engine starts, it sounds fine. This spring, when I can hook up a water supply...I will go through my checklist...checking filters, bleeding the fuel line etc... By the way, interesting cold start technique...I'd like to check this out further...let me grab my service manual...
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Jeff
Thanks. Will investigate...
Thanks all for the information. I'll be investigating as we start to prepare for launch. As far as I can recall, nothing was done to the engine before this problem started and it really was "all of a sudden".
Thanks all for the information. I'll be investigating as we start to prepare for launch. As far as I can recall, nothing was done to the engine before this problem started and it really was "all of a sudden".
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