That's another good place to check. Would this also explain why it only occurred when the boat was already in higher revs?
What on Earth is going on with my Yanmar 1GM10
- Thread starter Matt Adam
- Start date
I couldn't agree more. I would much rather have a blown transmission than end up with a fire onboard though so it was a rash decision.
Sorry, I must have misunderstood you. I'll add the fuel pump to the list. This week I'm going to break down as much as I can going system to system. Governor first, then fuel pump, then if that all fails, on to the piston rings.
Could be. The governor adjusts the fuel flow to maintain a set RPM, and if it stuck while you were accelerating, it would over speed when you reached that set point. Kind of like in a car of you held the pedal to the floor going up a hill, the engine would race when you crested over the top.
So based on this diagram (which hopefully I posted correctly) I'll probably want to inspect everything from the regulator spring down, right?
From my experience, a broken governor spring would have the reverse effect... the engine should throttle down, not up. Furthermore, there should be a rev limiter which prevents the governor lever from pulling the fuel pump lever too far and putting out too much fuel.
When the OP said he pulled the choke lever, I'm assuming that meant the fuel shut off. Doing that would easily override any tension on the governor spring and bring the fuel control lever back to the point where all the fuel is cut off.
OP also said that oil was splattered all over the bilge. Perhaps the 'runaway' ended when there was no oil left to combust.
When the OP said he pulled the choke lever, I'm assuming that meant the fuel shut off. Doing that would easily override any tension on the governor spring and bring the fuel control lever back to the point where all the fuel is cut off.
OP also said that oil was splattered all over the bilge. Perhaps the 'runaway' ended when there was no oil left to combust.
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Thing is, there was still oil left in the engine after things settled. So maybe I overfilled the case with oil and that exacerbated things? Also I still haven't identified the source of the oil spray. That part also worries me.
Is it possible that the oil could be from out of the transmission from the high RPM shifts, rather than from the engine itself? What's your transmission fluid level now?
Yeah, that could be possible. I need to check the levels when I go back down to the boat tomorrow evening. I didn't see any oil on the engine or transmission itself though. Obviously it's got to come from somewhere.
I asked a mechanic about oil leakage past the rings being the cause. He replied that if even a quarter of the oil needed to cause a runaway was leaking past the rings there would be quite a cloud of blue smoke coming from the exhaust. This would have been present weeks before the incident or if it was a broken oil ring then the blue cloud would be there every time the engine was run after the incident. Oil leakage from worn or broken rings doesn't just start and stop.
His first thought was malfunctioning governor. He said he had seen this often and it was always the governor.
He also recommended getting a mechanics opinion before arbitrarily deciding on an expensive ring job.
Hope this info help,
Chris
His first thought was malfunctioning governor. He said he had seen this often and it was always the governor.
He also recommended getting a mechanics opinion before arbitrarily deciding on an expensive ring job.
Hope this info help,
Chris
I am learning the ropes on my first sailboat, a 1985 Starwind 27 with a Yanmar 1GM10 diesel. I am slowly learning.
I had a runaway over the weekend. I had just changed the oil after replacing the exhaust elbow. Everything was looking great until a few minutes. I tried running full throttle (3,000 rpm) after it warmed up - I read that Yanmars need to go full throttle to clean out.
The speed maxed out about 3,500 rpm at dock in neutral. Turned out a lot of white smoke. Choking the fuel supply had no effect. The white smoke increased. This lasted about 2 minutes.
I was fortunate that one of the old hands from a few slips over came to my rescue and told me about shutting off the air supply. The engine shut down.
I found this thread and was able to confirm that I had overfilled the oil - Clear oil is hard to see in dim light.
I changed the oil and filter again and carefully checked the levels.
My problem now is that I can't restart the engine. I have tried bleeding the fuel. I get fuel under pressure at the fuel filter but can't seem to get it at the injector. Could I have damaged the injector? I have a new injector on order. Is there someplace else I could have damaged?
Any help greatly appreciated. I'll buy the beer in the Caribbean if i make it there in retirement. LOL
I had a runaway over the weekend. I had just changed the oil after replacing the exhaust elbow. Everything was looking great until a few minutes. I tried running full throttle (3,000 rpm) after it warmed up - I read that Yanmars need to go full throttle to clean out.
The speed maxed out about 3,500 rpm at dock in neutral. Turned out a lot of white smoke. Choking the fuel supply had no effect. The white smoke increased. This lasted about 2 minutes.
I was fortunate that one of the old hands from a few slips over came to my rescue and told me about shutting off the air supply. The engine shut down.
I found this thread and was able to confirm that I had overfilled the oil - Clear oil is hard to see in dim light.
I changed the oil and filter again and carefully checked the levels.
My problem now is that I can't restart the engine. I have tried bleeding the fuel. I get fuel under pressure at the fuel filter but can't seem to get it at the injector. Could I have damaged the injector? I have a new injector on order. Is there someplace else I could have damaged?
Any help greatly appreciated. I'll buy the beer in the Caribbean if i make it there in retirement. LOL
It sounds like engine oil was in the crankcase vent hose that goes to the intake manifold. When the boat was tilted the oil ran into the intake and the engine ran a way. That happens to my engine.
Check the fuel shut off lever on the engine, it might be stuck.
I doubt it's the injector.
Does the engine have compression?
I doubt it's the injector.
Does the engine have compression?
In many cases the crankcase breather goes back to the intake. So oil picked up into the breather could get sucked back into the air intake and provide the fuel needed for combustion.
It would stop the engine but the valves could strike the top of the piston and cause major damage. Best to block the air intake.
Thanks for that info! Certainly not the way I want to stop my engine...
what causes that? i Can open the levers when trying to start the engine with no damage?
Greg
Actually, I don't know. It is what Yanmar says in their operators manual. So I think they should know. Doesn't seem like a great thing to engineer into their engine though......... Also, I think Nigel Calder says the same thing in his book. I have great respect for his work.