Re: yanmar YSM8..injector pump?

Assuming you didn't post this to get product shoved your way, let me see if I can get you some advice. You must realize that the injector pump is designed to push a miniscule amount of fuel, but under very high pressure... As such, you will NOT see any significant volume when looking at the output while cranking, rather trickle or even just a few drops should be expected. I am not familiar with Yanmar that much, but I believe the YSM8 is a single cylinder engine so it's injector pump would push just a single miniscule "squirt" of diesel and then only once every other revolution. A very small amount indeed. With all air removed from the high pressure side however, this little squirt gets pushed to extreme pressure - higher than 10,000 psi - which is necessary to lift the needle in the injector against a heavy spring, thus atomizing the tiny squirt into the cylinder in order for it to autoignite and fire up the engine. Your engine probably uses less than .75 gallon per hour running at 3,000rpm - 1,500 squirts per minute or 90,000 squirts per hour, so a single push by the injector pump puts out approximately .75/90,000 or 0.0000083 gallon... A mere drip. Yes, the injector pump may be faulty in my opinion unlikely. I would eliminate any and all possibility of air traveling through the system first, then check the injector itself - if it is not atomizing the fuel the engine will not start. A weak or broken spring, or a worn seat will foul it up. could be worthwhile to replace that first - if it wasn't that you'll still have it as a spare. Hope this helps,

Thank you for the detailed reply. (I know it takes time to type insightful comments, so I am grateful) I can try another injector. This one is a new, aftermarket, that supposedly has 100% success rate. That assurance, plus availability convinced me to buy it. Yes, the exit of the injector pump displays the behavior you described. And while I’m not soliciting product, yes, I did get an offer of some, but it’s to be expected. I read it as “I’ll help diagnose and if you need an injector pump, I have one” because Joe is very knowledgeable also! : ) However, he also suggested some other, more laborious investigation, that while maybe necessary and certainly possible causes, are beyond the scope of my abilities/resources at this time. (tools, time, $$ for a haul-out, etc) Cylinder wall, con-rod, bottom end, liner, etc. And, again, finding an interested, reasonable mechanic to help me on-site, has been to no avail. I did have the 2 valves replaced, seats reground for the single cylinder head and he tested the springs for “in spec”. I can and will make one last attempt at a fuel bleed from the ‘racor’ on down and then…not sure, try another injector? (yes, trying to minimize how much ‘bit$’ I randomly throw at it without knowing what ailment I am trying to cure, other than ‘won’t start’) Next option? For Sale: Cute Cal 2-25 in Monterey, in excellent condition, setup for single-handing, needs engine work Thanks. ..tom From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] Sent: Tuesday, July 05, 2016 7:23 AM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] Re: yanmar YSM8..injector pump? Assuming you didn't post this to get product shoved your way, let me see if I can get you some advice. You must realize that the injector pump is designed to push a miniscule amount of fuel, but under very high pressure... As such, you will NOT see any significant volume when looking at the output while cranking, rather trickle or even just a few drops should be expected. I am not familiar with Yanmar that much, but I believe the YSM8 is a single cylinder engine so it's injector pump would push just a single miniscule "squirt" of diesel and then only once every other revolution. A very small amount indeed. With all air removed from the high pressure side however, this little squirt gets pushed to extreme pressure - higher than 10,000 psi - which is necessary to lift the needle in the injector against a heavy spring, thus atomizing the tiny squirt into the cylinder in order for it to autoignite and fire up the engine. Your engine probably uses less than .75 gallon per hour running at 3,000rpm - 1,500 squirts per minute or 90,000 squirts per hour, so a single push by the injector pump puts out approximately .75/90,000 or 0.0000083 gallon... A mere drip. Yes, the injector pump may be faulty in my opinion unlikely. I would eliminate any and all possibility of air traveling through the system first, then check the injector itself - if it is not atomizing the fuel the engine will not start. A weak or broken spring, or a worn seat will foul it up. could be worthwhile to replace that first - if it wasn't that you'll still have it as a spare. Hope this helps, --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

No worries - as an ex marine engineer and diesel mechanic with an office job, I actually enjoy talking diesel engines... It sounds like you have done a lot of work already, but one thing missing (unless I overlooked it) is reference to a compression check... Did you have the valves re-seated because of a bum compression check? From: TomDressler <tb… [at] verizon.net> To: Cal_Boats <Ca… [at] yahoogroups.com>; dutchessc22 <du… [at] aim.com> Sent: Tue, Jul 5, 2016 10:41 am Subject: RE: [Cal_Boats] Re: yanmar YSM8..injector pump? Thank you for the detailed reply. (I know it takes time to type insightful comments, so I am grateful) I can try another injector. This one is a new, aftermarket, that supposedly has 100% success rate. That assurance, plus availability convinced me to buy it. Yes, the exit of the injector pump displays the behavior you described. And while I’m not soliciting product, yes, I did get an offer of some, but it’s to be expected. I read it as “I’ll help diagnose and if you need an injector pump, I have one” because Joe is very knowledgeable also! : ) However, he also suggested some other, more laborious investigation, that while maybe necessary and certainly possible causes, are beyond the scope of my abilities/resources at this time. (tools, time, $$ for a haul-out, etc) Cylinder wall, con-rod, bottom end, liner, etc. And, again, finding an interested, reasonable mechanic to help me on-site, has been to no avail. I did have the 2 valves replaced, seats reground for the single cylinder head and he tested the springs for “in spec”. I can and will make one last attempt at a fuel bleed from the ‘racor’ on down and then…not sure, try another injector? (yes, trying to minimize how much ‘bit$’ I randomly throw at it without knowing what ailment I am trying to cure, other than ‘won’t start’) Next option? For Sale: Cute Cal 2-25 in Monterey, in excellent condition, setup for single-handing, needs engine work Thanks. ..tom From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] Sent: Tuesday, July 05, 2016 7:23 AM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] Re: yanmar YSM8..injector pump? Assuming you didn't post this to get product shoved your way, let me see if I can get you some advice. You must realize that the injector pump is designed to push a miniscule amount of fuel, but under very high pressure... As such, you will NOT see any significant volume when looking at the output while cranking, rather trickle or even just a few drops should be expected. I am not familiar with Yanmar that much, but I believe the YSM8 is a single cylinder engine so it's injector pump would push just a single miniscule "squirt" of diesel and then only once every other revolution. A very small amount indeed. With all air removed from the high pressure side however, this little squirt gets pushed to extreme pressure - higher than 10,000 psi - which is necessary to lift the needle in the injector against a heavy spring, thus atomizing the tiny squirt into the cylinder in order for it to autoignite and fire up the engine. Your engine probably uses less than .75 gallon per hour running at 3,000rpm - 1,500 squirts per minute or 90,000 squirts per hour, so a single push by the injector pump puts out approximately .75/90,000 or 0.0000083 gallon... A mere drip. Yes, the injector pump may be faulty in my opinion unlikely. I would eliminate any and all possibility of air traveling through the system first, then check the injector itself - if it is not atomizing the fuel the engine will not start. A weak or broken spring, or a worn seat will foul it up. could be worthwhile to replace that first - if it wasn't that you'll still have it as a spare. Hope this helps, This email has been checked for viruses by Avast antivirus software. www.avast.com

Thanks. I had the valves replaced because as I watch the intake side, I saw fuel spraying back into the intake port, when the valve was supposed to be closed. The disassembly confirmed that both valves were not sealing. And inspection of the block revealed some possible gasket leakage at the exhaust side. I have not done a “compression check”. While I am familiar with gasoline , 4 stroke and 2 stroke engines, the diesel, no-plug system is new to me, other than knowing they use, fuel, air, compression and heat of the system to ignite. From: du… [at] aim.com [mailto:du… [at] aim.com] Sent: Tuesday, July 05, 2016 8:23 AM To: tb… [at] verizon.net; Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: yanmar YSM8..injector pump? No worries - as an ex marine engineer and diesel mechanic with an office job, I actually enjoy talking diesel engines... It sounds like you have done a lot of work already, but one thing missing (unless I overlooked it) is reference to a compression check... Did you have the valves re-seated because of a bum compression check? From: TomDressler < <mailto:tb… [at] verizon.net> tb… [at] verizon.net> To: Cal_Boats < <mailto:Ca… [at] yahoogroups.com> Ca… [at] yahoogroups.com>; dutchessc22 < <mailto:du… [at] aim.com> du… [at] aim.com> Sent: Tue, Jul 5, 2016 10:41 am Subject: RE: [Cal_Boats] Re: yanmar YSM8..injector pump? Thank you for the detailed reply. (I know it takes time to type insightful comments, so I am grateful) I can try another injector. This one is a new, aftermarket, that supposedly has 100% success rate. That assurance, plus availability convinced me to buy it. Yes, the exit of the injector pump displays the behavior you described. And while I’m not soliciting product, yes, I did get an offer of some, but it’s to be expected. I read it as “I’ll help diagnose and if you need an injector pump, I have one” because Joe is very knowledgeable also! : ) However, he also suggested some other, more laborious investigation, that while maybe necessary and certainly possible causes, are beyond the scope of my abilities/resources at this time. (tools, time, $$ for a haul-out, etc) Cylinder wall, con-rod, bottom end, liner, etc. And, again, finding an interested, reasonable mechanic to help me on-site, has been to no avail. I did have the 2 valves replaced, seats reground for the single cylinder head and he tested the springs for “in spec”. I can and will make one last attempt at a fuel bleed from the ‘racor’ on down and then…not sure, try another injector? (yes, trying to minimize how much ‘bit$’ I randomly throw at it without knowing what ailment I am trying to cure, other than ‘won’t start’) Next option? For Sale: Cute Cal 2-25 in Monterey, in excellent condition, setup for single-handing, needs engine work Thanks. ..tom From: <mailto:Ca… [at] yahoogroups.com> Ca… [at] yahoogroups.com [ <mailto:Ca… [at] yahoogroups.com?> mailto:Ca… [at] yahoogroups.com] Sent: Tuesday, July 05, 2016 7:23 AM To: <mailto:Ca… [at] yahoogroups.com> Ca… [at] yahoogroups.com Subject: [Cal_Boats] Re: yanmar YSM8..injector pump? Assuming you didn't post this to get product shoved your way, let me see if I can get you some advice. You must realize that the injector pump is designed to push a miniscule amount of fuel, but under very high pressure... As such, you will NOT see any significant volume when looking at the output while cranking, rather trickle or even just a few drops should be expected. I am not familiar with Yanmar that much, but I believe the YSM8 is a single cylinder engine so it's injector pump would push just a single miniscule "squirt" of diesel and then only once every other revolution. A very small amount indeed. With all air removed from the high pressure side however, this little squirt gets pushed to extreme pressure - higher than 10,000 psi - which is necessary to lift the needle in the injector against a heavy spring, thus atomizing the tiny squirt into the cylinder in order for it to autoignite and fire up the engine. Your engine probably uses less than .75 gallon per hour running at 3,000rpm - 1,500 squirts per minute or 90,000 squirts per hour, so a single push by the injector pump puts out approximately .75/90,000 or 0.0000083 gallon... A mere drip. Yes, the injector pump may be faulty in my opinion unlikely. I would eliminate any and all possibility of air traveling through the system first, then check the injector itself - if it is not atomizing the fuel the engine will not start. A weak or broken spring, or a worn seat will foul it up. could be worthwhile to replace that first - if it wasn't that you'll still have it as a spare. Hope this helps, _____ <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> Avast logo This email has been checked for viruses by Avast antivirus software. <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> www.avast.com --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Hmmm... sounds like the engine has been under duress at least at some time and for some reason: Non-seating valves, exhaust gasket leak... I believe this is a raw water cooled engine, no? (Here I am thinking of calcified cooling passages with subsequent cylinder liner and head overheating)... Either way, with "issues" all surrounding the cylinder, I am leaning more and more towards lack of compression as the cause of your non-start. Compression check can be done by removing the injector - if it comes in at less than 300 PSI, with your valves already serviced, you'd be looking at either a bad head gasket or worn/broken piston ring(s) - the latter would result in blow-by into the crankcase. I am surprised that whoever did the disassembly for the valves didn't follow through with a compression check. From: TomDressler <tb… [at] verizon.net> To: dutchessc22 <du… [at] aim.com>; Cal_Boats <Ca… [at] yahoogroups.com> Sent: Tue, Jul 5, 2016 11:41 am Subject: RE: [Cal_Boats] Re: yanmar YSM8..injector pump? Thanks. I had the valves replaced because as I watch the intake side, I saw fuel spraying back into the intake port, when the valve was supposed to be closed. The disassembly confirmed that both valves were not sealing. And inspection of the block revealed some possible gasket leakage at the exhaust side. I have not done a “compression check”. While I am familiar with gasoline , 4 stroke and 2 stroke engines, the diesel, no-plug system is new to me, other than knowing they use, fuel, air, compression and heat of the system to ignite. From: du… [at] aim.com [mailto:du… [at] aim.com] Sent: Tuesday, July 05, 2016 8:23 AM To: tb… [at] verizon.net; Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: yanmar YSM8..injector pump? No worries - as an ex marine engineer and diesel mechanic with an office job, I actually enjoy talking diesel engines... It sounds like you have done a lot of work already, but one thing missing (unless I overlooked it) is reference to a compression check... Did you have the valves re-seated because of a bum compression check? From: TomDressler <tb… [at] verizon.net> To: Cal_Boats <Ca… [at] yahoogroups.com>; dutchessc22 <du… [at] aim.com> Sent: Tue, Jul 5, 2016 10:41 am Subject: RE: [Cal_Boats] Re: yanmar YSM8..injector pump? Thank you for the detailed reply. (I know it takes time to type insightful comments, so I am grateful) I can try another injector. This one is a new, aftermarket, that supposedly has 100% success rate. That assurance, plus availability convinced me to buy it. Yes, the exit of the injector pump displays the behavior you described. And while I’m not soliciting product, yes, I did get an offer of some, but it’s to be expected. I read it as “I’ll help diagnose and if you need an injector pump, I have one” because Joe is very knowledgeable also! : ) However, he also suggested some other, more laborious investigation, that while maybe necessary and certainly possible causes, are beyond the scope of my abilities/resources at this time. (tools, time, $$ for a haul-out, etc) Cylinder wall, con-rod, bottom end, liner, etc. And, again, finding an interested, reasonable mechanic to help me on-site, has been to no avail. I did have the 2 valves replaced, seats reground for the single cylinder head and he tested the springs for “in spec”. I can and will make one last attempt at a fuel bleed from the ‘racor’ on down and then…not sure, try another injector? (yes, trying to minimize how much ‘bit$’ I randomly throw at it without knowing what ailment I am trying to cure, other than ‘won’t start’) Next option? For Sale: Cute Cal 2-25 in Monterey, in excellent condition, setup for single-handing, needs engine work Thanks. ..tom From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] Sent: Tuesday, July 05, 2016 7:23 AM To: Ca… [at] yahoogroups.com Subject: [Cal_Boats] Re: yanmar YSM8..injector pump? Assuming you didn't post this to get product shoved your way, let me see if I can get you some advice. You must realize that the injector pump is designed to push a miniscule amount of fuel, but under very high pressure... As such, you will NOT see any significant volume when looking at the output while cranking, rather trickle or even just a few drops should be expected. I am not familiar with Yanmar that much, but I believe the YSM8 is a single cylinder engine so it's injector pump would push just a single miniscule "squirt" of diesel and then only once every other revolution. A very small amount indeed. With all air removed from the high pressure side however, this little squirt gets pushed to extreme pressure - higher than 10,000 psi - which is necessary to lift the needle in the injector against a heavy spring, thus atomizing the tiny squirt into the cylinder in order for it to autoignite and fire up the engine. Your engine probably uses less than .75 gallon per hour running at 3,000rpm - 1,500 squirts per minute or 90,000 squirts per hour, so a single push by the injector pump puts out approximately .75/90,000 or 0.0000083 gallon... A mere drip. Yes, the injector pump may be faulty in my opinion unlikely. I would eliminate any and all possibility of air traveling through the system first, then check the injector itself - if it is not atomizing the fuel the engine will not start. A weak or broken spring, or a worn seat will foul it up. could be worthwhile to replace that first - if it wasn't that you'll still have it as a spare. Hope this helps, This email has been checked for viruses by Avast antivirus software. www.avast.com This email has been checked for viruses by Avast antivirus software. www.avast.com