I ordered a new kill switch from Torreson today and some other Yanmar 2QM15 panel parts. Jeremy, the parts guy, asked how I have been shutting down the engine if mine was broken. I have been shutting the engine down by reducing the throttle until it stalls. He said the kill switch should be used and a low idle should never shut it down. He said I should have the idle reset... The engine experiences a (i) rough idle (ii) hard starting and (iii) some black smoke (especially at startup). Reading other postings and Calder I think indicates either a problem with the fuel injectors and/or the need for valve adjustment. Believing that a valve adjustment to be relatively simple I think I can check that myself. I'm afraid to screw with the injectors -- I think I'm over my head with that. Any thoughts?
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Sir Charles:
If you are going to pay to have the injectors checked you might just as well have the mechanic do the valve adjustment too. If they are going to go through a diagnosis on what is wrong with your engine, they need to check the valve clearance too. The valves on a 2GM is suppose to be done every 500 hours (probably the same on your engine). I think that the idea of an engine not shutting down with a low idle has more to do with safety thank anything. Be sure that you check out the mechanic before you hire him. I recommend a certified Yanmar specialist. I have had several friends that used a "Diesel Mechanic" and have had the work re-done.
If you are going to pay to have the injectors checked you might just as well have the mechanic do the valve adjustment too. If they are going to go through a diagnosis on what is wrong with your engine, they need to check the valve clearance too. The valves on a 2GM is suppose to be done every 500 hours (probably the same on your engine). I think that the idea of an engine not shutting down with a low idle has more to do with safety thank anything. Be sure that you check out the mechanic before you hire him. I recommend a certified Yanmar specialist. I have had several friends that used a "Diesel Mechanic" and have had the work re-done.
Valve adjustment, injectors and timing
It can never hurt to check and readjust the valves. When so doing, take note of clearance before adjusting. If the gap is loose, you could have wear on the operating side and if tight you might have seat erosion. If the clearance is at zero, you may have burned valves. If you have maintained clean fuel, injectors seldom cause problems. They do sometimes accumulate soot at the discharge that affects the spray pattern, which is critical. Of greater concern is the injection timing. We have seen many times that a hard starting engine is repaired by resetting the injection timing. We have also smoothed the operation of the Q series engines by adjusting the timing of injection. This is not an easy process, requiring carefull and accurate measurement and the removal of the injection pump to change shim thickness which controls the timing. You should probably start with the relatively simple valve clearance check (you may need a gasket). Then remove the injectors and have a reliable injector shop check them out (new parts required for reinstallation). If the problems aren't gone, get an experienced Yanmar mechanic to check and adjust the injection timing. Another check that should be made is the compression pressure. This requires a good tester, designed for diesel and in good operation condition. You should get readings above 350 PSIG. If less, confirm the gauge accuracy and be prepared to overhaul.
It can never hurt to check and readjust the valves. When so doing, take note of clearance before adjusting. If the gap is loose, you could have wear on the operating side and if tight you might have seat erosion. If the clearance is at zero, you may have burned valves. If you have maintained clean fuel, injectors seldom cause problems. They do sometimes accumulate soot at the discharge that affects the spray pattern, which is critical. Of greater concern is the injection timing. We have seen many times that a hard starting engine is repaired by resetting the injection timing. We have also smoothed the operation of the Q series engines by adjusting the timing of injection. This is not an easy process, requiring carefull and accurate measurement and the removal of the injection pump to change shim thickness which controls the timing. You should probably start with the relatively simple valve clearance check (you may need a gasket). Then remove the injectors and have a reliable injector shop check them out (new parts required for reinstallation). If the problems aren't gone, get an experienced Yanmar mechanic to check and adjust the injection timing. Another check that should be made is the compression pressure. This requires a good tester, designed for diesel and in good operation condition. You should get readings above 350 PSIG. If less, confirm the gauge accuracy and be prepared to overhaul.
I was taught to kill the engine by stalling it...
... and it always has been shut off that way from day one (since it's the only way). Now I need a "kill switch" instead?!
... and it always has been shut off that way from day one (since it's the only way). Now I need a "kill switch" instead?!
MDR George,
Geo: Who taught you that trick? Must have been the guy that sold you your first diesel engine. We need to hear more about this. Are you telling us that your engine does NOT have a fuel shut off (aka kill switch)? Which engine/which boat?
Geo: Who taught you that trick? Must have been the guy that sold you your first diesel engine. We need to hear more about this. Are you telling us that your engine does NOT have a fuel shut off (aka kill switch)? Which engine/which boat?
Right on both counts... 1977/78 Yanmar SB8.
Thanks! (I assume you'll tell me where how to wire one in, I hope...) MDR George
Thanks! (I assume you'll tell me where how to wire one in, I hope...) MDR George
MDR George.
I am not very familiar with your engine BUTTTT, I must assume that there is some sort of fuel shut off on the engine. Normally this has a cable on it that runs from the engine to the Yanmar panel. You should have some sort of a hole in your boat near the Yanmar panel that has a hole for the cable. This cable (when pulled) will shut off the flow of fuel at the engine. We re-routed our fuel shut off from the cockpit to the top of the engine compartment. These cables tend to corrode easily. When you are in a salt water environment they corrode quicker. We use a Morse cable that I installed 10 years ago. It works as good today as the day I installed it, but it is now out of the elements. This is an easy thing to do once you find the lever for the fuel shut off. Let me know if I can help. I'll be glad to post a picture on the Photo Forum of my end result. Don't know if I can be of much help as to part numbers. Gordon can point you in the direction to the lever and some part numbers too.
I am not very familiar with your engine BUTTTT, I must assume that there is some sort of fuel shut off on the engine. Normally this has a cable on it that runs from the engine to the Yanmar panel. You should have some sort of a hole in your boat near the Yanmar panel that has a hole for the cable. This cable (when pulled) will shut off the flow of fuel at the engine. We re-routed our fuel shut off from the cockpit to the top of the engine compartment. These cables tend to corrode easily. When you are in a salt water environment they corrode quicker. We use a Morse cable that I installed 10 years ago. It works as good today as the day I installed it, but it is now out of the elements. This is an easy thing to do once you find the lever for the fuel shut off. Let me know if I can help. I'll be glad to post a picture on the Photo Forum of my end result. Don't know if I can be of much help as to part numbers. Gordon can point you in the direction to the lever and some part numbers too.
Diesels not all created equal
All diesel engines are shut down by removing the supply of fuel. The method of stopping the fuel is not always the same. The early Yanmars used the throttle cable to stop the engine, there is a detent at idle speed and the throttle handle is moved beyond the detent to shut off the fuel. Many engines have a pull cable that stops the fuel supply. Some have a solenoid that is actuated by a push button, shutting off the fuel. Some have a solenoid that is actuated when the switch is turned on and it stays energized until the switch is turned off, which stops the fuel. I'm sure there are other methods but the goal is the same, make it quiet.
All diesel engines are shut down by removing the supply of fuel. The method of stopping the fuel is not always the same. The early Yanmars used the throttle cable to stop the engine, there is a detent at idle speed and the throttle handle is moved beyond the detent to shut off the fuel. Many engines have a pull cable that stops the fuel supply. Some have a solenoid that is actuated by a push button, shutting off the fuel. Some have a solenoid that is actuated when the switch is turned on and it stays energized until the switch is turned off, which stops the fuel. I'm sure there are other methods but the goal is the same, make it quiet.
My only fuel shutoff is the petcock threaded onto
the top of the fuel tank. One turns the valve handle 90-degrees to shutoff fuel flow. (I generally do this after having turned off the engine prior to leaving the boat). You're suggesting that it better to kill fuel flow to the engine this way while the engine is idling until it dies, as opposed to closing the throttle?
the top of the fuel tank. One turns the valve handle 90-degrees to shutoff fuel flow. (I generally do this after having turned off the engine prior to leaving the boat). You're suggesting that it better to kill fuel flow to the engine this way while the engine is idling until it dies, as opposed to closing the throttle?
Hey George! Me Too!
I have a YSB 12. To shut it down I pull the throttle cable and stall the engine. Like you, I have no solinoid, nor do I have a cut off switch. I was instructed by a Yanmar mechanic that that is how it works, and is supposed to work. Don't be alarmed. You're shutting off your engine just like everybody else...by depriving it of fuel.
I have a YSB 12. To shut it down I pull the throttle cable and stall the engine. Like you, I have no solinoid, nor do I have a cut off switch. I was instructed by a Yanmar mechanic that that is how it works, and is supposed to work. Don't be alarmed. You're shutting off your engine just like everybody else...by depriving it of fuel.
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