I've been reading the post on the "Diesel Bug" which got me thinking about my own boat. I had a technician look at my one cylinder Yanmar that he could not get to work although it does turn over. The diesel fuel has been sitting for several years in the tank, I did add some new fuel to the tank but neglected to remove the old fuel. I wonder if the engine won't start because of old fuel. The tech. seemed to think it may need a total overhaul however he may not have realized that old fuel had been stored in the fuel tank. Any thoughts appreciated, I'm think of draining the fuel adding a biocide and new diesel fuel.
Speaking of diesel fuel...
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mostlikely it's the fuel
The cool thing about desiel, other then they have a better air-fuel mixture (better gas mileage) is that they don't need a spark to run. So as long as the cylinder has ok pressure (rings or valves aren't totally blown) then it should start if a) cranks fast enough to get the pressure b) in cold weather it needs some kind of heat primer (some prime the fuel: fuel heater, and some prime the cylinder: glow plugs) so if the glow plugs are working in cold weather c) good fuel. I once saw desiel fuel so old that I was able to take a burning newspaper and throw it into a bucket of it and it didn't burn...just put out the flame like water. So...normal temp you just need compression and good fuel.
The cool thing about desiel, other then they have a better air-fuel mixture (better gas mileage) is that they don't need a spark to run. So as long as the cylinder has ok pressure (rings or valves aren't totally blown) then it should start if a) cranks fast enough to get the pressure b) in cold weather it needs some kind of heat primer (some prime the fuel: fuel heater, and some prime the cylinder: glow plugs) so if the glow plugs are working in cold weather c) good fuel. I once saw desiel fuel so old that I was able to take a burning newspaper and throw it into a bucket of it and it didn't burn...just put out the flame like water. So...normal temp you just need compression and good fuel.
Diesel
You will need to get all the old fuel out of the system. All the way to the injectors. So system needs to be bled. Be sure to replace the filters, including the one on the engine. If the engine turns over and feels like it has good compression, it will run with good fuel in it. The Yanmars are almost indestructible.
You will need to get all the old fuel out of the system. All the way to the injectors. So system needs to be bled. Be sure to replace the filters, including the one on the engine. If the engine turns over and feels like it has good compression, it will run with good fuel in it. The Yanmars are almost indestructible.
two things
1) Yanmars do not have glow plugs nor fuel preheaters. 2) "diesel bugs" are not bugs at all but algae that grows in the water in the tank. There must be water present for it to grow. No water, no algae. If you have it it will show up in your filters, but its too late at that point 'cuz it will already be in your injectors.
1) Yanmars do not have glow plugs nor fuel preheaters. 2) "diesel bugs" are not bugs at all but algae that grows in the water in the tank. There must be water present for it to grow. No water, no algae. If you have it it will show up in your filters, but its too late at that point 'cuz it will already be in your injectors.
Steve
I'm not so sure your right there. The instructions on my boat says to turn the key to the left for 7 seconds, then to the right to start. That 7 seconds is to warm something up (I've been meaning to check but keep forgetting). Diesel engines need heat and compression and fuel to fire. When the engine is running it generates it's own heat. On days where the temp is above 70* the compression from starting is enough heat. When it's cold, diesel engines need something to heat up the fuel so it can fire. I haven't checked to see what I have, but I must have something unless Yanmars has discovered how to build diesel engines that no other manufacture has learned yet. Oh yeah...some engines have either (SP?) that gets injected for the intual starting but that's not a common starting method.
I'm not so sure your right there. The instructions on my boat says to turn the key to the left for 7 seconds, then to the right to start. That 7 seconds is to warm something up (I've been meaning to check but keep forgetting). Diesel engines need heat and compression and fuel to fire. When the engine is running it generates it's own heat. On days where the temp is above 70* the compression from starting is enough heat. When it's cold, diesel engines need something to heat up the fuel so it can fire. I haven't checked to see what I have, but I must have something unless Yanmars has discovered how to build diesel engines that no other manufacture has learned yet. Oh yeah...some engines have either (SP?) that gets injected for the intual starting but that's not a common starting method.
Diesel will not easily ignite
A correction below on another post - diesel fuel does not easily ignite like gasoline does. Diesel self combusts under pressure and heat. That is the built-in safety factor of having diesel onboard - it is not very flamable unless under presuure so throwing a burning newspaper into a bucket of diesel will unlikey ignite.
A correction below on another post - diesel fuel does not easily ignite like gasoline does. Diesel self combusts under pressure and heat. That is the built-in safety factor of having diesel onboard - it is not very flamable unless under presuure so throwing a burning newspaper into a bucket of diesel will unlikey ignite.
Wrong and right
Yes, it's not like gas, but I use diesel all the time on the farm to burn fallen trees. Yes, it needs heat...what do you think a flame generates?
Yes, it's not like gas, but I use diesel all the time on the farm to burn fallen trees. Yes, it needs heat...what do you think a flame generates?
I think I should clarify
As I said in another thread, for a diesel engine to fire, you need compression and heat and fuel. For Diesel to burn, you just need heat (dont' believe me...take a stick and dip it in diesel and put a ligher to it...it will burn). Now a match or cigerette thrown into a bucket of diesel will not do anything, but a burning newspaper will because it has a lot more heat. Also, Diesel fumes don't catch like gas fumes do too, so that's why diesel is so much safter then gas.
As I said in another thread, for a diesel engine to fire, you need compression and heat and fuel. For Diesel to burn, you just need heat (dont' believe me...take a stick and dip it in diesel and put a ligher to it...it will burn). Now a match or cigerette thrown into a bucket of diesel will not do anything, but a burning newspaper will because it has a lot more heat. Also, Diesel fumes don't catch like gas fumes do too, so that's why diesel is so much safter then gas.
Diesel and fire.
When I was in the service, we used to dispose of unservicable ammunition (mainly small arms) by burning in a pit with diesel fuel. It takes alot to ignite diesel fuel. We used a black powder charge with six minutes of time fuze. Most of the time, it worked, but on occassion, it failed. And this was in the desert where the temperature was well over 70.
When I was in the service, we used to dispose of unservicable ammunition (mainly small arms) by burning in a pit with diesel fuel. It takes alot to ignite diesel fuel. We used a black powder charge with six minutes of time fuze. Most of the time, it worked, but on occassion, it failed. And this was in the desert where the temperature was well over 70.
Cetane rating decreases with age
You can add cetane boosters but I agree that the best thing would be new fuel. My Volvo MD11C doesn't have a heating device. It does have a cold start device that injects more fuel. But on cold days I have found that if I direct warm air from a small electric heater at the air intake that the engine starts much more quickly. When the air is above 70 the engine starts very quickly. I only use the heater if the temperature was near freezing the night before. You may want to check the injectors and the compression before you do any major work. Tom
You can add cetane boosters but I agree that the best thing would be new fuel. My Volvo MD11C doesn't have a heating device. It does have a cold start device that injects more fuel. But on cold days I have found that if I direct warm air from a small electric heater at the air intake that the engine starts much more quickly. When the air is above 70 the engine starts very quickly. I only use the heater if the temperature was near freezing the night before. You may want to check the injectors and the compression before you do any major work. Tom
diesel engine
Hi, Diesel engines, although simple from an electrical standpoint (no spark, timing, points, etc.) are still pretty complicated. Yes, all you need is fuel and compression, but making sure you have fuel (in the right amount and at the right time) and compression (also the right amount) is not so simple. Otherwise why would every third post be about engines? As others wrote, you need to do a few things before you know if the motor is ok or not. Do a compression test in the engine. Your rings, valves, pistons, head gasket, etc. ma y be bad. If those items are not in good condition your engine won't run. If the compression test shows that the engine internal are OK, then you can work on the fuel problem. Remove all the old fuel. Then change the fuel filters. Then bleed the fuel lines. Then see if the fuel injector and injector system are working. Now you may be able to start the engine. Good luck! Barry
Hi, Diesel engines, although simple from an electrical standpoint (no spark, timing, points, etc.) are still pretty complicated. Yes, all you need is fuel and compression, but making sure you have fuel (in the right amount and at the right time) and compression (also the right amount) is not so simple. Otherwise why would every third post be about engines? As others wrote, you need to do a few things before you know if the motor is ok or not. Do a compression test in the engine. Your rings, valves, pistons, head gasket, etc. ma y be bad. If those items are not in good condition your engine won't run. If the compression test shows that the engine internal are OK, then you can work on the fuel problem. Remove all the old fuel. Then change the fuel filters. Then bleed the fuel lines. Then see if the fuel injector and injector system are working. Now you may be able to start the engine. Good luck! Barry
links
Some excellent Diesel Fuel Information resources: ”Long Term Storage of Diesel Fuel”
from BP Australia) http://www.bp.com.au/fuelnews/ADF1402.pdf 6-12 months at temps of 30* C or higher or 12 months or longer at 20 degrees C or LOWER An excellent article !!! “Diesel Fuel - Fungal Contamination”: http://www.bp.com.au/fuelnews/ADF1502.pdf This deals specifically with diesel fuel used in boats See also: BP Australia - Fuel News Topics http://www.bp.com.au/products/fuelnews/topics.asp Including “Common Diesel Problems” (1) http://www.bp.com.au/fuelnews/ADF0907.pdf (2) http://www.bp.com.au/fuelnews/ADF1006.pdf (3) http://www.bp.com.au/fuelnews/ADF1107.pdf and more ...
Some excellent Diesel Fuel Information resources: ”Long Term Storage of Diesel Fuel”
from BP Australia) http://www.bp.com.au/fuelnews/ADF1402.pdf 6-12 months at temps of 30* C or higher or 12 months or longer at 20 degrees C or LOWER An excellent article !!! “Diesel Fuel - Fungal Contamination”: http://www.bp.com.au/fuelnews/ADF1502.pdf This deals specifically with diesel fuel used in boats See also: BP Australia - Fuel News Topics http://www.bp.com.au/products/fuelnews/topics.asp Including “Common Diesel Problems” (1) http://www.bp.com.au/fuelnews/ADF0907.pdf (2) http://www.bp.com.au/fuelnews/ADF1006.pdf (3) http://www.bp.com.au/fuelnews/ADF1107.pdf and more ...- Status