All that work to get an early splash. Couple of warm days with south breezes and I cannot leave the slip. No engine because no waterpump. The old Jabsco(2760-003) started leaking and I do not have the seals to rebuild it. I did this a few years ago but I think the bearings might be a problem. If the shaft is wobbling then how long can the seals last? This appears to be a very weak link on the old Yanmar(2QM20F). The pump is the pedestal type, two bolt holes just two inches apart. It seems like too much stress from the belt around the crank and alternator for such a small mounting. On the other hand it has performed flawlessly for the five years I have owned her. . . until now. Has anyone replaced this pump with a newer and better model? In the catalogs it looks like Johnson might have a replacement. The problem is bolting it down and still having the pulley(4") line up with the alternator and crank. I'll be calling Torresen later today, they provided the original rebuild kit. What about a backup? Has anyone installed an electric pump nearby that could be used in an emergency?
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2QM 20
Ed, I haven't had that pump problem yet but would like to be prepared. Please let us know your solution.
Ed, I haven't had that pump problem yet but would like to be prepared. Please let us know your solution.
Solution is $$$.
Just got off the phone with DEPCO, see related link. I should have waited for more help from all of you but I am too impatient. I bought a new 2760($221) and a kit for the old one($30.) He said he got thirty 2760s delivered and had one left! Says they are a good pump and I should stick with it. Still thinking about an electric backup. (If you cannot open PDFs(Acrobat) then just www.depcopump.com)
Just got off the phone with DEPCO, see related link. I should have waited for more help from all of you but I am too impatient. I bought a new 2760($221) and a kit for the old one($30.) He said he got thirty 2760s delivered and had one left! Says they are a good pump and I should stick with it. Still thinking about an electric backup. (If you cannot open PDFs(Acrobat) then just www.depcopump.com)
Over the alternator, too?
My pump sits on it's own mount, and uses it's own belt. The alterntor has it's own pulley. This little pump doesn't need much belt tension to pump and not have the belt slip, unlike the alternator. I can't imagine the little 3/8" or so bronze shaft and small bearings holding up to the same loads as the alternator, even in you just have the old 35 amp standard one. I would seriously consider putting the new pump, whatever one you end up using, on it's own pulley and belt.
My pump sits on it's own mount, and uses it's own belt. The alterntor has it's own pulley. This little pump doesn't need much belt tension to pump and not have the belt slip, unlike the alternator. I can't imagine the little 3/8" or so bronze shaft and small bearings holding up to the same loads as the alternator, even in you just have the old 35 amp standard one. I would seriously consider putting the new pump, whatever one you end up using, on it's own pulley and belt.
on the 2qm15.....
I have the 2qm15, and my water pump belt only runs the water pump. The drive wheel doubles up two belts though, one for the water pump, one for the alternator. With this set up, the alternator belt is tensioned by the alternator, and the water pump belt is tightened by the the water pump. Some mechanics say they both need to be tight, but a very trustworthy and knowledgeable Yanmar mechanic told me it is not as vital to have the water pump belt as tight as the alternator belt. Obviously, it needs to be tight enough to run the pump without slipping, but less tension may solve your problem. I am assuming you have a similar set up, sorry for making you read this if yours is set up differently. Good luck!
I have the 2qm15, and my water pump belt only runs the water pump. The drive wheel doubles up two belts though, one for the water pump, one for the alternator. With this set up, the alternator belt is tensioned by the alternator, and the water pump belt is tightened by the the water pump. Some mechanics say they both need to be tight, but a very trustworthy and knowledgeable Yanmar mechanic told me it is not as vital to have the water pump belt as tight as the alternator belt. Obviously, it needs to be tight enough to run the pump without slipping, but less tension may solve your problem. I am assuming you have a similar set up, sorry for making you read this if yours is set up differently. Good luck!
Gene and Brian.
Wish it were true. My crank pulley only has one belt groove. Your setup would be perfect. Maybe I can find a Yanmar crank wheel. Then I will have to offset the waterpump somehow to line up the belt. Is there no end to boat projects!!
Wish it were true. My crank pulley only has one belt groove. Your setup would be perfect. Maybe I can find a Yanmar crank wheel. Then I will have to offset the waterpump somehow to line up the belt. Is there no end to boat projects!!
Ed, get off your band wagon.
Ed: Get off your band wagon. <g> If you did not have boat projects what would you do. You tackle those big projects like the NFM ports. Big holding tanks etc etc. Retirement is just around the corner, what will you do for those 8-10 hrs. every day? (Boat Projects, that is what you will do). I presume that you are going to install the new pump and rebuild the old one for a back up. That is not a bad idea. For $30 you have a B/U water pump. Be sure to test it before you need it. PS: How many DAYS do you have left before the big 'R'.
Ed: Get off your band wagon. <g> If you did not have boat projects what would you do. You tackle those big projects like the NFM ports. Big holding tanks etc etc. Retirement is just around the corner, what will you do for those 8-10 hrs. every day? (Boat Projects, that is what you will do). I presume that you are going to install the new pump and rebuild the old one for a back up. That is not a bad idea. For $30 you have a B/U water pump. Be sure to test it before you need it. PS: How many DAYS do you have left before the big 'R'.
Work days?
With the freefall of my savings there may never be a retirement. But the plan is to subtract May 1 from December 31 to get the answer. Not sure about testing it but the old one will have to be the backup. After reading what Gene and Brian wrote maybe I created my own problem. Remember that new higher amp alternator I installed? Well I actually installed it with LESS belt tension. I have always worried about the load on the waterpump so I thought I was lessening it. But when I watched the engine run there was a slight oscillation of the belt. The belt was tracking OK but you could see it moving down and up a quarter of an inch. But then the engine has been run less than thirty minutes with this alternator. So who knows?
With the freefall of my savings there may never be a retirement. But the plan is to subtract May 1 from December 31 to get the answer. Not sure about testing it but the old one will have to be the backup. After reading what Gene and Brian wrote maybe I created my own problem. Remember that new higher amp alternator I installed? Well I actually installed it with LESS belt tension. I have always worried about the load on the waterpump so I thought I was lessening it. But when I watched the engine run there was a slight oscillation of the belt. The belt was tracking OK but you could see it moving down and up a quarter of an inch. But then the engine has been run less than thirty minutes with this alternator. So who knows?
SPARE PUMPS
Ed: The ultimate solution to carrying spares: Just tow a whole 'nother boat and you'll have a spare everything. I too have gone the backup pump route. My 3QM30 has the same jabsco water pump which has a bad habit of eating impellers. I broke down and bought a duplicate from West Marine, a rebuild kit, 4 spare impellers, and also had a spare mounting bracket made (which craked under the strain). I put the new one on the motor, and rebuilt the old one (seals gasket, impeller). The bearings appeared to be in good shape, but the seal would "weep" a couple of drops a minute before rebuilding. I can now tell by the sound when the impeller starts going.
Ed: The ultimate solution to carrying spares: Just tow a whole 'nother boat and you'll have a spare everything. I too have gone the backup pump route. My 3QM30 has the same jabsco water pump which has a bad habit of eating impellers. I broke down and bought a duplicate from West Marine, a rebuild kit, 4 spare impellers, and also had a spare mounting bracket made (which craked under the strain). I put the new one on the motor, and rebuilt the old one (seals gasket, impeller). The bearings appeared to be in good shape, but the seal would "weep" a couple of drops a minute before rebuilding. I can now tell by the sound when the impeller starts going.
Two Comments
Ed: the electric backup idea definitely will work - used a 12 volt Water Puppy from west marine for about 10 hours, worked fine, used the pump for washdown duty the rest of the time. Second, am I understanding that for the 2&3QM series I will have trouble finding new or rebuilt water pumps that replace my original? By the way, I have 2QM15, belt runs somewhat more slack than alternator belt generally, don't have any problems with belt wear or pump leakage (knock on wood).
Ed: the electric backup idea definitely will work - used a 12 volt Water Puppy from west marine for about 10 hours, worked fine, used the pump for washdown duty the rest of the time. Second, am I understanding that for the 2&3QM series I will have trouble finding new or rebuilt water pumps that replace my original? By the way, I have 2QM15, belt runs somewhat more slack than alternator belt generally, don't have any problems with belt wear or pump leakage (knock on wood).
Good to hear.
That's what I had in mind Jim, have to be careful with volume. The Jabsco is rated at around 4 GPM at 2100 RPM. From what I found at DEPCO the 2760 is still their workhorse. If that is what you have then the pumps and the parts are readily available. It sounds like you have the double pulley and two belts, the ideal arrangement. I wonder if my crank pulley has two grooves and I just never noticed it? Maybe I can bolt something on the front if not. Or just install a new 3GM30.
That's what I had in mind Jim, have to be careful with volume. The Jabsco is rated at around 4 GPM at 2100 RPM. From what I found at DEPCO the 2760 is still their workhorse. If that is what you have then the pumps and the parts are readily available. It sounds like you have the double pulley and two belts, the ideal arrangement. I wonder if my crank pulley has two grooves and I just never noticed it? Maybe I can bolt something on the front if not. Or just install a new 3GM30.
Don't laugh about a spare boat
One of the Ginzburgs, the one who published the avante guard Screw magazine, used to say he kept a spare Rolls Royce to cannablize parts and kept them in the trunk of the first Rolls. He really came to detest the Rolls, which is solace for the rest of us.
One of the Ginzburgs, the one who published the avante guard Screw magazine, used to say he kept a spare Rolls Royce to cannablize parts and kept them in the trunk of the first Rolls. He really came to detest the Rolls, which is solace for the rest of us.
Ed, only one groove on mine !
Ed, I checked the pics that I have of my 2QM and can only see one groove. I have the same belt mounting as you have. Have you noticed any significant engine loading with the new higher amp alternator ? Richard H37C Rhapsodie
Ed, I checked the pics that I have of my 2QM and can only see one groove. I have the same belt mounting as you have. Have you noticed any significant engine loading with the new higher amp alternator ? Richard H37C Rhapsodie
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My 3QM-30 has only one groove on the crank sheave also, but there are three tapped holes in the face. I checked with Yanmar (2 distributors) today looking for a bolt-on sheave, but got nowhere. My engine has after-market fresh water cooling, and the same Jabsco pump is run by the same single belt. In order to tension the belt adequately to run the 105-A alternator, the pump is squeezed almost into the crank pulley! The side-loading this produces is also bad; it would be a lot better to drive the water pump off the other side of the crank and on its own belt. If anyone finds such a sheave, please post to this list. By the way, I replaced the thoroughly trashed Jabsco this year.
My 3QM-30 has only one groove on the crank sheave also, but there are three tapped holes in the face. I checked with Yanmar (2 distributors) today looking for a bolt-on sheave, but got nowhere. My engine has after-market fresh water cooling, and the same Jabsco pump is run by the same single belt. In order to tension the belt adequately to run the 105-A alternator, the pump is squeezed almost into the crank pulley! The side-loading this produces is also bad; it would be a lot better to drive the water pump off the other side of the crank and on its own belt. If anyone finds such a sheave, please post to this list. By the way, I replaced the thoroughly trashed Jabsco this year.
Tapped holes?
That is good news Dave. I have noticed those holes but never checked them for threads. Should not be that difficult to find something to bolt on there. Then make a better mounting bracket to get the pump lined up and all done. The new bracket will have to have slotted holes in order to have adjustment for belt tightening. Richard, since I only went from a 35 amp to 55 amp I doubt that I will notice a difference. Especially since my batteries are always fully charged and I only motor the fifteen minutes each direction on the river. But I would guess Dave must notice that 105A alternator. Again, though, if the batteries are charged then there is no load.
That is good news Dave. I have noticed those holes but never checked them for threads. Should not be that difficult to find something to bolt on there. Then make a better mounting bracket to get the pump lined up and all done. The new bracket will have to have slotted holes in order to have adjustment for belt tightening. Richard, since I only went from a 35 amp to 55 amp I doubt that I will notice a difference. Especially since my batteries are always fully charged and I only motor the fifteen minutes each direction on the river. But I would guess Dave must notice that 105A alternator. Again, though, if the batteries are charged then there is no load.
Electric?
Curious regarding an electric back-up. Would you have to be very careful about operation separate from the engine running to avoid flooding the engine? If it comes on with the ignition, you would have to make sure you started the engine immediately. Seems like it might make a viable back-up, but maybe a dangerous primary. Dan Jonas (S/V Feije II)
Curious regarding an electric back-up. Would you have to be very careful about operation separate from the engine running to avoid flooding the engine? If it comes on with the ignition, you would have to make sure you started the engine immediately. Seems like it might make a viable back-up, but maybe a dangerous primary. Dan Jonas (S/V Feije II)
Engine damage?
You could be right Dan. You are thinking that with no exhaust pressure the water might back up onto the exhaust valves? Could happen. It would definitely be for emergency only. In fact you could use a bilge pump. Let the water from the inlet go into the bilge and hook the bilge pump hose to the engine. Might be too much capacity, 2000 GPH is about 34 GPM. Versus 4 GPM? Guess not.
You could be right Dan. You are thinking that with no exhaust pressure the water might back up onto the exhaust valves? Could happen. It would definitely be for emergency only. In fact you could use a bilge pump. Let the water from the inlet go into the bilge and hook the bilge pump hose to the engine. Might be too much capacity, 2000 GPH is about 34 GPM. Versus 4 GPM? Guess not.
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