I'm still trying to figure out an engine problem. I replaced a Perko fuel seperator with a Racor several months ago on my 3GMF and added a bulb between the fuel tank and the Racor. Never had an issue with stalling or losing power before that day. Since then she's had problems losing RPM's (only) while motoring and occassionally stalling. I've replaced fuel lines and filters and (visually) checked many times for leaks. The problem does not occur in the slip or at slow motoring speeds but only while motoring above 1500 RPM. When she does stall I can usually just start her right back up without having to bleed her. Everyone I speak to including Yanmar mechanics say it sounds like air is in the system but I can't figure out where it's coming from. Is there something I can do to verify if this is the problem? Thanks, Joe Mullee
- Status
AIR ?????
The way this thing runs and then quits it does sound like air in the fuel system. But I find this hard to accept if it starts back up after quitting. If it gets enough air in the fuel system to make the engine stall, I seriously doubt it will restart without bleeding. The 3GM in my boat will not start with only a tiny burp of air in front of the injector pump. My inclination would be to look for a fuel blockage of some sort. Maybe a stopped up vent line to the tank. Have you tried it without the primer bulb. These things have check valves in them, and even new ones have screwed up. I may be totally wrong, but thats certainly the direction I would start looking.
The way this thing runs and then quits it does sound like air in the fuel system. But I find this hard to accept if it starts back up after quitting. If it gets enough air in the fuel system to make the engine stall, I seriously doubt it will restart without bleeding. The 3GM in my boat will not start with only a tiny burp of air in front of the injector pump. My inclination would be to look for a fuel blockage of some sort. Maybe a stopped up vent line to the tank. Have you tried it without the primer bulb. These things have check valves in them, and even new ones have screwed up. I may be totally wrong, but thats certainly the direction I would start looking.
Sounds like you answered your own queston.
If you had no problem until you added the Racor and the bulb they have to be the source. I'd plumb around the Racors and bulb and give it a test run. If the problem goes away, the Racor, bulb or their installation is the problem.
If you had no problem until you added the Racor and the bulb they have to be the source. I'd plumb around the Racors and bulb and give it a test run. If the problem goes away, the Racor, bulb or their installation is the problem.
Sure
Disconnect the fuel line at the fuel pump and blow the fuel in the line back to the tank (a small pump or air hose works just fine). Close the fuel shut-off valve at the fuel tank. Apply a small amount of air pressure to the open end. With a spray bottle of soapy water spray every connection in between checking for bubbles. In normal operation this is the suction side of the fuel line and therefore you would not see any leaks. By applying air pressure and soapy water they all become visible.
Disconnect the fuel line at the fuel pump and blow the fuel in the line back to the tank (a small pump or air hose works just fine). Close the fuel shut-off valve at the fuel tank. Apply a small amount of air pressure to the open end. With a spray bottle of soapy water spray every connection in between checking for bubbles. In normal operation this is the suction side of the fuel line and therefore you would not see any leaks. By applying air pressure and soapy water they all become visible.
What did you use on the threads?
What did you use on the threads to seal the joints? If you used teflon tape you shouldn't have. The diesel fuel breaks down the tape which can cause leaks and or blockages. Not sure why you installed the bulb but it would be the first thing I removed or bypassed to troubleshoot.
What did you use on the threads to seal the joints? If you used teflon tape you shouldn't have. The diesel fuel breaks down the tape which can cause leaks and or blockages. Not sure why you installed the bulb but it would be the first thing I removed or bypassed to troubleshoot.
Sorry you are having to be the guinea pig Joe
I am still holding off installing mine ( that is my story and I am sticking to it!) I agree with plumbing around the filter first and see if everything runs alright- you might want to run out of a new fuel container with fresh fuel for this- if everything runs fine I would go back to running thru the filter and take the bulb out of the line. It sounds like one or the other. Good luck- Post your findings PLEASE!
I am still holding off installing mine ( that is my story and I am sticking to it!) I agree with plumbing around the filter first and see if everything runs alright- you might want to run out of a new fuel container with fresh fuel for this- if everything runs fine I would go back to running thru the filter and take the bulb out of the line. It sounds like one or the other. Good luck- Post your findings PLEASE!
Maybe not
the air. With my Yanmar or my old westerbeke on my Cal, if any air is in the system, it will not run until I bleed it. Sounds like something else, but that is just my opinion. I am not familiar with the bulb as I do not incorporate one between my tank and Racor. Good Luck and let us know Greg
the air. With my Yanmar or my old westerbeke on my Cal, if any air is in the system, it will not run until I bleed it. Sounds like something else, but that is just my opinion. I am not familiar with the bulb as I do not incorporate one between my tank and Racor. Good Luck and let us know Greg
Stalling 3GMF
I have a 1986 Cal33 with the 3GMF in it. Last year I had the same type of problem. I also installed the primer bulb the year before but that was not a problem, it makes it real easy to get the air out of the system. The real problem was the fuel tank. I pulled it out of the boat and had it cleaned out plus it had a screen at the bottom of the pickup tube. I had the screen removed. It shouldn't be there anyway. I also replaced the fuel lines from the tank to the Racor filter. I increased the fuel line size slightly to 5/16 hose. This solved the stalling problem. I suspect you could have this same clogged fuel tank problem. Then I got some slow fuel leaks, so over last winter I replaced all the metal fuel lines and bleeder screws on the engine right up to the injector pump. No more leaks. She runs like a new engine. I didn't stop there, I had the engine pressure checked to be sure the engine is sound after 20 years. It is! Then they checked my fuel injectors and found one not so good one so all the injectors were replaced. I did this just for some piece of mind over the coming years. Still runs like a new engine. I also replaced/beefed up the battery cables from the starter to the battery switch and then on to the new car starter battery. She cranks like a mother now. I did this before all the fuel problems. Best of Luck, Chuck
I have a 1986 Cal33 with the 3GMF in it. Last year I had the same type of problem. I also installed the primer bulb the year before but that was not a problem, it makes it real easy to get the air out of the system. The real problem was the fuel tank. I pulled it out of the boat and had it cleaned out plus it had a screen at the bottom of the pickup tube. I had the screen removed. It shouldn't be there anyway. I also replaced the fuel lines from the tank to the Racor filter. I increased the fuel line size slightly to 5/16 hose. This solved the stalling problem. I suspect you could have this same clogged fuel tank problem. Then I got some slow fuel leaks, so over last winter I replaced all the metal fuel lines and bleeder screws on the engine right up to the injector pump. No more leaks. She runs like a new engine. I didn't stop there, I had the engine pressure checked to be sure the engine is sound after 20 years. It is! Then they checked my fuel injectors and found one not so good one so all the injectors were replaced. I did this just for some piece of mind over the coming years. Still runs like a new engine. I also replaced/beefed up the battery cables from the starter to the battery switch and then on to the new car starter battery. She cranks like a mother now. I did this before all the fuel problems. Best of Luck, Chuck
Fuel Pick Up Tube Was My Problem
I experienced the same symptoms with my 2GM20F. Mechanics and friends all thought it was an air leak somewhere in the system. Finally decided to polish the fuel and on entering the tank I discovered the fuel pickup tube was square on the bottom and a sag in the plastic fuel tank top was permitting the tube to rest flush on the bottom. After a period of running it was trying to suck a vacuumn. Made a diagonal cut on the tube end so it can continue to rest on the bottom and problem was solved. Took me several months and three tows before I found my solution. Good luck.
I experienced the same symptoms with my 2GM20F. Mechanics and friends all thought it was an air leak somewhere in the system. Finally decided to polish the fuel and on entering the tank I discovered the fuel pickup tube was square on the bottom and a sag in the plastic fuel tank top was permitting the tube to rest flush on the bottom. After a period of running it was trying to suck a vacuumn. Made a diagonal cut on the tube end so it can continue to rest on the bottom and problem was solved. Took me several months and three tows before I found my solution. Good luck.
Check the bulb
As others have suggested, check the squeeze bulb. I had a similar problem on a previous boat. I had installed a squeeze bulb on my fuel system. It worked well for the first season but the second year the engine would loose power intermittently at 1,500 - 2,000 RPM. The engine quit entirely one day and after extensive trouble shooting at anchor, I removed and bypassed the bulb and the engine ran fine. It turned out that a piece of the valving mechanism inside the bulb had come loose and would float around and occasionaly block the fuel flow. Perhaps your problem is something simple like a bulb that is installed backwards so that the check valves close at higher RPM and stop the fuel flow.
As others have suggested, check the squeeze bulb. I had a similar problem on a previous boat. I had installed a squeeze bulb on my fuel system. It worked well for the first season but the second year the engine would loose power intermittently at 1,500 - 2,000 RPM. The engine quit entirely one day and after extensive trouble shooting at anchor, I removed and bypassed the bulb and the engine ran fine. It turned out that a piece of the valving mechanism inside the bulb had come loose and would float around and occasionaly block the fuel flow. Perhaps your problem is something simple like a bulb that is installed backwards so that the check valves close at higher RPM and stop the fuel flow.
FWIW
A few years ago I changed my Racor filter. After about 20 hrs of motoring, I was motor-sailing back to Martha's Vineyard from Nantucket. My engine coughed and spewed white smoke (it was smoke since I was able to watch it drift away over the water), but didn't stall, just lost rpm's for a short while. I was told by a reputable mechanic, on this board, that it was an air bubble. I have since changed it without a problem, yet.
A few years ago I changed my Racor filter. After about 20 hrs of motoring, I was motor-sailing back to Martha's Vineyard from Nantucket. My engine coughed and spewed white smoke (it was smoke since I was able to watch it drift away over the water), but didn't stall, just lost rpm's for a short while. I was told by a reputable mechanic, on this board, that it was an air bubble. I have since changed it without a problem, yet.
Yanmars are quite 'forgiving' when sucking air ...
It really takes a LOT of air to stall a Yanmar. Possible causes of 'gross' air leaks 1. Compression fittings (used with copper fuel lines) are NOTORIOUS air leakers. Compression fittings are simply not designed to be opened/reused, their design is for 'one tightening only' then the tube should be trimmed or cut back a NEW ferrule installed and then retightened. Double flared fittings avoid the 'problems' of compression fittings that 'let go' when the 'dimpled' copper under the compression ferrule releaves itself of the stress. 2. Roy makes a valid point but also too many boat builders put a coarse screen over the dip tube if it it gets partly blocked the system will run at higher vacuum (differential pressure) thus promoting 'air leakage'. Ditto with a tank vent mounted externally on a boat that has an insect nest built inside it. 3. The flat gaskets, etc. used on Racors and the engine 'guard' filter need to be installed 'wetted' with fuel oil. If installed 'dry' then can often allow air to bypass the gasket (but not oil). 4. Rarely but can happen the diapharagm of a lift pump will develop a pin hole and depending on the exact location (has to do with hydrodynamics) will either pump a teeny amount of fuel into the crankcase and will suck air from the crankcase throiugh the diaphragm on the 'return stroke'. My recommendations to you are: A. remove and reinstall all the filters, this time installing all the gaskets and O-rings .... wetted with fuel oil. B. remove any compression fitting that you previoiusly removed and check for CRACKS in the ferrules and seal nuts .... if you find any ferrules that 'easily fall off', trim the copper back and reinstall with a NEW ferrule onto previously uncompressed copper line C. Check the tank vent, the dip tube, etc. for obstruction D. Check lift pump for rupturing diaphragm (pin holes developing). E. Temporarily add a 12v electric fuel pump (compatible with #2 oil / diesel fuel) and temporarily run the system as a PRESSURE FEED system. If that works successfully ... you DO have an air leak so re-examine all the filter housing for cracks (at the fitting connection ports), then begin to change all the compression fittings for new .... if the boat is OLD consider to replace the old copper (reactive with fuel oil) line; preferably with double flared stainless steel, etc. Adding 12v pump at the tank-end of the circuit will greatly aid in bleeding the entire delivery system: filters/line/lift pump, etc. .... and can be left 'silent' in-line and onstream without 12v energization .... and the system will NOT be adversely affected; plus you can energize that pump in place of a broken lift pump. If you need to find a leak, simply energize the 12v pump with the engine OFF and simply wait an hour or so, then look for the 'wetspot' resulting from the 'leak'. F. Install a 'bubble trap' in the fuel line between the lift pump and the injector pump .... simply a small filter housing (same as the engine 'guard filter' housing) but install it UPSIDE-DOWN. Being upside down (and initially FILLED with oil) will trap the air bubbles (by gravimetric separation of the oil/air) that are being pulled into the system. You will need to install a clear Tygon, etc. plastic tube and small valve to the (now) top of the bowl (in its inverted position) and simply purge the air from the inverted bowl when you see air in the vertical 'pig-tail' on the bowl. My 'bets' (in order of typical occurance) is that you inadventantly 'ripped' a filter gasket when you installed. Next bet is - cracked a compression fitting or filter housing connection port. Use proper 5 sided 'fitting wrenches' on fittings and NOT 2 sided common 'box' wrenches. Next ... if the boat is 'old', corroded copper fuel line with small pin-hole. Partly blocked tank vent or dip tube. IF that 'squeeze bulb' is made of BUNA or Neoprene Rubber get RID of it and change to one made of EPR (EthylenePropyleneRubber) or better EPDM (EthylenePropyleneDiamineMonomer) which are MORE compatible with fuel oil than Neoprene or Buna used in GASOLINE service. Hope this helps.
It really takes a LOT of air to stall a Yanmar. Possible causes of 'gross' air leaks 1. Compression fittings (used with copper fuel lines) are NOTORIOUS air leakers. Compression fittings are simply not designed to be opened/reused, their design is for 'one tightening only' then the tube should be trimmed or cut back a NEW ferrule installed and then retightened. Double flared fittings avoid the 'problems' of compression fittings that 'let go' when the 'dimpled' copper under the compression ferrule releaves itself of the stress. 2. Roy makes a valid point but also too many boat builders put a coarse screen over the dip tube if it it gets partly blocked the system will run at higher vacuum (differential pressure) thus promoting 'air leakage'. Ditto with a tank vent mounted externally on a boat that has an insect nest built inside it. 3. The flat gaskets, etc. used on Racors and the engine 'guard' filter need to be installed 'wetted' with fuel oil. If installed 'dry' then can often allow air to bypass the gasket (but not oil). 4. Rarely but can happen the diapharagm of a lift pump will develop a pin hole and depending on the exact location (has to do with hydrodynamics) will either pump a teeny amount of fuel into the crankcase and will suck air from the crankcase throiugh the diaphragm on the 'return stroke'. My recommendations to you are: A. remove and reinstall all the filters, this time installing all the gaskets and O-rings .... wetted with fuel oil. B. remove any compression fitting that you previoiusly removed and check for CRACKS in the ferrules and seal nuts .... if you find any ferrules that 'easily fall off', trim the copper back and reinstall with a NEW ferrule onto previously uncompressed copper line C. Check the tank vent, the dip tube, etc. for obstruction D. Check lift pump for rupturing diaphragm (pin holes developing). E. Temporarily add a 12v electric fuel pump (compatible with #2 oil / diesel fuel) and temporarily run the system as a PRESSURE FEED system. If that works successfully ... you DO have an air leak so re-examine all the filter housing for cracks (at the fitting connection ports), then begin to change all the compression fittings for new .... if the boat is OLD consider to replace the old copper (reactive with fuel oil) line; preferably with double flared stainless steel, etc. Adding 12v pump at the tank-end of the circuit will greatly aid in bleeding the entire delivery system: filters/line/lift pump, etc. .... and can be left 'silent' in-line and onstream without 12v energization .... and the system will NOT be adversely affected; plus you can energize that pump in place of a broken lift pump. If you need to find a leak, simply energize the 12v pump with the engine OFF and simply wait an hour or so, then look for the 'wetspot' resulting from the 'leak'. F. Install a 'bubble trap' in the fuel line between the lift pump and the injector pump .... simply a small filter housing (same as the engine 'guard filter' housing) but install it UPSIDE-DOWN. Being upside down (and initially FILLED with oil) will trap the air bubbles (by gravimetric separation of the oil/air) that are being pulled into the system. You will need to install a clear Tygon, etc. plastic tube and small valve to the (now) top of the bowl (in its inverted position) and simply purge the air from the inverted bowl when you see air in the vertical 'pig-tail' on the bowl. My 'bets' (in order of typical occurance) is that you inadventantly 'ripped' a filter gasket when you installed. Next bet is - cracked a compression fitting or filter housing connection port. Use proper 5 sided 'fitting wrenches' on fittings and NOT 2 sided common 'box' wrenches. Next ... if the boat is 'old', corroded copper fuel line with small pin-hole. Partly blocked tank vent or dip tube. IF that 'squeeze bulb' is made of BUNA or Neoprene Rubber get RID of it and change to one made of EPR (EthylenePropyleneRubber) or better EPDM (EthylenePropyleneDiamineMonomer) which are MORE compatible with fuel oil than Neoprene or Buna used in GASOLINE service. Hope this helps.
Responses
There are some good responses on here, and most make good sense. Particularly ones concerning the fuel line pickup in the tank. The fact remains that if you were to get enough air in the system to cause the engine to stall, it would not restart. The Yanmars will digest some air and keep running, as Paul stated, but they will not start with air in the system. A few weeks ago I had a problem with mine. It would run forever with no problems. But once it was shut down it would not restart without bleeding the system all the way to the injectors. I finally found a pin hole in the fuel line close to the tank, which allowed it to suck air into the line. The leak was not large enough to cause the engine to quit running, or cause any problem. But the tiny air bubbles in the line would accumulate in a high spot once the engine was shut down, and then as soon as they hit the injector pump on restart, that was the end till the system was once again bled. Also as stated, the squeeze bulbs are for the most part not made for diesel, and the little check valves in them are prone to failure. I am pretty sure that your problem is fuel starvation, not air in the system. Your description sounds much more like a fuel tank pickup tube that is partly clogged or a vent line that is clogged. But since your problems started with the installation of the new filter and bulb, I would certainly start looking at these two items. I would run the engine till it starts to stall, or stalls, then loosen the filler cap on the tank and see if that cures the problem. If that cures it the vent line is clogged, if it doesn't the vent is OK. That is by far the simplest cure to try, and always start with the easiest and simplest cure. Many times we don't see the forest for the trees.
There are some good responses on here, and most make good sense. Particularly ones concerning the fuel line pickup in the tank. The fact remains that if you were to get enough air in the system to cause the engine to stall, it would not restart. The Yanmars will digest some air and keep running, as Paul stated, but they will not start with air in the system. A few weeks ago I had a problem with mine. It would run forever with no problems. But once it was shut down it would not restart without bleeding the system all the way to the injectors. I finally found a pin hole in the fuel line close to the tank, which allowed it to suck air into the line. The leak was not large enough to cause the engine to quit running, or cause any problem. But the tiny air bubbles in the line would accumulate in a high spot once the engine was shut down, and then as soon as they hit the injector pump on restart, that was the end till the system was once again bled. Also as stated, the squeeze bulbs are for the most part not made for diesel, and the little check valves in them are prone to failure. I am pretty sure that your problem is fuel starvation, not air in the system. Your description sounds much more like a fuel tank pickup tube that is partly clogged or a vent line that is clogged. But since your problems started with the installation of the new filter and bulb, I would certainly start looking at these two items. I would run the engine till it starts to stall, or stalls, then loosen the filler cap on the tank and see if that cures the problem. If that cures it the vent line is clogged, if it doesn't the vent is OK. That is by far the simplest cure to try, and always start with the easiest and simplest cure. Many times we don't see the forest for the trees.
Fuel strainer in tank
Joe Sorry to hear you are still having problems. Make sure that all the hoses are in perfect condition and that the hose clamps are tight. I have had it on a new beneteau that the fuel supply hose fitting was not tight and let in air when the engine was in gear but it was fine when out of gear due to movement of the engine. Make sure the hoses are not too short and pinching when the engine moves. Only fit one hose clamp if the barbed section is short as two clamps can work against each other and cause a leak. It may be starvation. There is a small mesh strainer inside to riser pipe in the fuel tank. I had this block up in mine with debris from the fuel and it gave similar effects as you describe. Why it should occur just after fitting the new filter is strange. To remove it you have to take off the hose just after the shut off valve on top of the tank. Unscrew the valve assembly from the top of the tank and the pipe should come out. The mesh is up inside the pipe. If thats clear then it may be the small secondary fuel filter that is on the side of the engine just after the lift pump. It may also be the lift pump itself. I replaced mine as the seats were damaged. To get access to this its best to remove the side panel which is held in with just a few screws. I got mine from Go2 marine for about $100. Good luck Richard
Joe Sorry to hear you are still having problems. Make sure that all the hoses are in perfect condition and that the hose clamps are tight. I have had it on a new beneteau that the fuel supply hose fitting was not tight and let in air when the engine was in gear but it was fine when out of gear due to movement of the engine. Make sure the hoses are not too short and pinching when the engine moves. Only fit one hose clamp if the barbed section is short as two clamps can work against each other and cause a leak. It may be starvation. There is a small mesh strainer inside to riser pipe in the fuel tank. I had this block up in mine with debris from the fuel and it gave similar effects as you describe. Why it should occur just after fitting the new filter is strange. To remove it you have to take off the hose just after the shut off valve on top of the tank. Unscrew the valve assembly from the top of the tank and the pipe should come out. The mesh is up inside the pipe. If thats clear then it may be the small secondary fuel filter that is on the side of the engine just after the lift pump. It may also be the lift pump itself. I replaced mine as the seats were damaged. To get access to this its best to remove the side panel which is held in with just a few screws. I got mine from Go2 marine for about $100. Good luck Richard
Yanmar Primer Bulb
Tell me about the "primer bulb", as I have not used one on my 1979 Yanmar 2QM20F!
Tell me about the "primer bulb", as I have not used one on my 1979 Yanmar 2QM20F!
Tom, about the primer bulb...
This is an outboard primer bulb that I have installed in line between the fuel pump and the secondary filter on my yanmar diesel. It aids in bleeding the the fuel system as the little primer lever on the fuel pump is hard to reach and doesn't push a lot of fuel. It would also serve as a emergency hand opperated fuel pump.
This is an outboard primer bulb that I have installed in line between the fuel pump and the secondary filter on my yanmar diesel. It aids in bleeding the the fuel system as the little primer lever on the fuel pump is hard to reach and doesn't push a lot of fuel. It would also serve as a emergency hand opperated fuel pump.
A Few More Questions
Air in the system: The last time out (3 days ago) I stalled three times when I was at 50-90% throttle. Each time I was able to restart without bleeding the engine. When I motored at 25-40% throttle I did not have the problem. This leads me to believe my problem is something other than air in the system. Fuel blockage: The fuel blockage never happened in the six years before I changed filters. I will check this but because it was never a problem before I have to think it's unlikely to develope just as I change filters. Question #1 - Location: Previously when I had the old Perko it was located directly in line with the fuel pump. That is, if you drew a straight line from the fuel tank to the engine the Perko was placed directly in that line. The Racor Series 230 is too big to fit where the Perko was located. I had to move it to the other side of the engine box and run the line from the fuel tank to the Racor and then back to the engine. I probably addded 4 feet of additional fuel line with several twists and turns. Could the problem be that the fuel pump isn't strong enough to draw the fuel the extra distance with efficiency? Question #2 - Size: Is the Racor 230 too big? It's rated for 30 GPH and I'm now using a 30 micron filter. From what I can read it appears many other boaters use the Racor 110 which is smaller. Could that bigger Racor associated with the extra distance to the fuel pump be the cause of any starvation? As always, thanks for all the advice. Every answer received is a good one which helps me think this thing through until the problem is solved. I'll be heading to the boat again tommorow and will use the suggestions here to help me figure this thing out. Joe Mullee
Air in the system: The last time out (3 days ago) I stalled three times when I was at 50-90% throttle. Each time I was able to restart without bleeding the engine. When I motored at 25-40% throttle I did not have the problem. This leads me to believe my problem is something other than air in the system. Fuel blockage: The fuel blockage never happened in the six years before I changed filters. I will check this but because it was never a problem before I have to think it's unlikely to develope just as I change filters. Question #1 - Location: Previously when I had the old Perko it was located directly in line with the fuel pump. That is, if you drew a straight line from the fuel tank to the engine the Perko was placed directly in that line. The Racor Series 230 is too big to fit where the Perko was located. I had to move it to the other side of the engine box and run the line from the fuel tank to the Racor and then back to the engine. I probably addded 4 feet of additional fuel line with several twists and turns. Could the problem be that the fuel pump isn't strong enough to draw the fuel the extra distance with efficiency? Question #2 - Size: Is the Racor 230 too big? It's rated for 30 GPH and I'm now using a 30 micron filter. From what I can read it appears many other boaters use the Racor 110 which is smaller. Could that bigger Racor associated with the extra distance to the fuel pump be the cause of any starvation? As always, thanks for all the advice. Every answer received is a good one which helps me think this thing through until the problem is solved. I'll be heading to the boat again tommorow and will use the suggestions here to help me figure this thing out. Joe Mullee
Double check your work
Joe, double check all your work, especially the additional section of fuel line you added. You mentioned lots of twists and turns, make sure you don't have any kinks or other restrictions to the fuel flow. While you probably could have used the smaller filter I would think using the next size up isn't the problem. Is it located in a place where you could watch it while someone else drove the boat? This way when you got to the stalling point you could see if the bowl in the filter looks starved for fuel. I would think that your problem is directly related to the changes you made. That's not to say something else could have failed simultaneously. I've had that happen. I did battle with a similiar problem when my boat was new. Simliar symptoms in that it wouldn't run well above 1500 rpm and would sometimes stall. It turned out to be my fuel pump was bad. Wired in a new one and as soon as I put power to it you could hear the difference. I would still do a thorough check of your work before you start replacing parts that were fine before your retrofit. Two rules of thumb I've learned in 38 years in a services led business, 1. if it's not broken, don't fix it, 2. if it broke right after you did something to it then it's most likely something you did, not a part failure. Good luck and keep us posted. Mike
Joe, double check all your work, especially the additional section of fuel line you added. You mentioned lots of twists and turns, make sure you don't have any kinks or other restrictions to the fuel flow. While you probably could have used the smaller filter I would think using the next size up isn't the problem. Is it located in a place where you could watch it while someone else drove the boat? This way when you got to the stalling point you could see if the bowl in the filter looks starved for fuel. I would think that your problem is directly related to the changes you made. That's not to say something else could have failed simultaneously. I've had that happen. I did battle with a similiar problem when my boat was new. Simliar symptoms in that it wouldn't run well above 1500 rpm and would sometimes stall. It turned out to be my fuel pump was bad. Wired in a new one and as soon as I put power to it you could hear the difference. I would still do a thorough check of your work before you start replacing parts that were fine before your retrofit. Two rules of thumb I've learned in 38 years in a services led business, 1. if it's not broken, don't fix it, 2. if it broke right after you did something to it then it's most likely something you did, not a part failure. Good luck and keep us posted. Mike
Ditto on double checking your work .....
Recheck/retighen ALL the tube fittings and the filter gaskets. Also, if you are operating your Racor with an installed vacuum gauge, and because your Racor is apparently greatly oversized and because you are using a 30uM cartridge that doesnt have much flow restriction through the filter media ....... ...... IF the racor vacuum gage is reading any noticeable vacuum, then you may have a restriction between the filter and the tank. What usually happens especially if the length of the tube is long or the tube drops to a horizontal level lower than the filter ... rust particles and soft (goo) partciles agglomerate can easily form a 'cake' in the low section of the tube, thus eventually blocking it. This is not uncommon. So if the vacuum reading when the engine is near full throttle is reading moderate or higher vacuum ... there IS a restriction between the tank and filter set. Such high vacuum conditions will allow air to get sucked through the compression fittings OR across the flat gaskets / o-rings in the filter housings. A good stiff wire run through the tube will usually dislodge any 'cake' of particles.
Recheck/retighen ALL the tube fittings and the filter gaskets. Also, if you are operating your Racor with an installed vacuum gauge, and because your Racor is apparently greatly oversized and because you are using a 30uM cartridge that doesnt have much flow restriction through the filter media ....... ...... IF the racor vacuum gage is reading any noticeable vacuum, then you may have a restriction between the filter and the tank. What usually happens especially if the length of the tube is long or the tube drops to a horizontal level lower than the filter ... rust particles and soft (goo) partciles agglomerate can easily form a 'cake' in the low section of the tube, thus eventually blocking it. This is not uncommon. So if the vacuum reading when the engine is near full throttle is reading moderate or higher vacuum ... there IS a restriction between the tank and filter set. Such high vacuum conditions will allow air to get sucked through the compression fittings OR across the flat gaskets / o-rings in the filter housings. A good stiff wire run through the tube will usually dislodge any 'cake' of particles.
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