That can be frustrating and for me it did take several tries. One thing I did that helped was I applied a small amount of grease to the key and that helped "stick" it in place while I put it all together. You could potentially use another light temporary adhesive to hold it in place, but for me the grease was something that was safe for the system and gave it just enough stick to get it together.
I very much appreciate your posting. The 4.5 that I have had dislodged a piece of its impeller, sending it up just to the top of the copper tube/ rubber grommet at the intake of the water jacket, where it promptly melted, and occluded the water delivery tube! Wow! Who knew with "nano" tech you could get outboard motors to cream themselves like that! ?!? But seriously, I wonder if some kind of VERY low temperature melting "grease" might be a good idea if new impeller doesn't see like INSTANT H2O?
Hi, I think that the Mariner 4 is basically the same? Either way thanks so much for your informative videos, they take away most of the the 'scary bits'. . . If they are similar, I wonder and hope that you might have a video dealing with the gear oil/lubricant and how to replace it. - - Keep up the good work - - Best regards, Dave.
By the way, on my 1998 Merc 5hp, and others with a similar build, the drive shaft can be a real bugger to get back into place. The reason for this is that the drive shaft tends to miss the tube that it's supposed to go into. This is made worse by the task of aligning the shift shaft with the shift shaft clamp. This process causes the drive shaft to go in at an angle. When the drive shaft misses the tube, it will go up into the housing to the SIDE of the tube. Then it will go no further when the lower end has about two inches to go before the two halves are mated. If this is happening to you, I suggest you take a flashlight and carefully make sure the end of the drive shaft is heading toward the tube while aligning the shift shaft. I finally gave up and took the shift shaft clamp OFF and just concentrated on getting the drive shaft where it belonged. I was able to attach the clamp with a pair of needle nose pliers through the side port that is provided for loosening the clamp. I Hope this makes sense. It will to anyone who has spent the hours of frustration that I did trying to figure out why my drive shaft would not go all the way in!
Just as you said, It could really be either of those two. Clog, or Impeller. I would heck for clogs first as the clog is the cheaper fix of the two. Check the pickup screen/pipe and see if it is all clear. If you pull junk out of it and it gets all better, then free fix. But if there is no visible clog you may want to open it up and check the impeller. (or if there is an internal clog.)
Good question. I used some grease to hold the key in place. Any sticky or semi-sticky substance could work. As for which I stuck the key too, If I remember right I stuck the key to the shaft and then slid the impeller over it.
Thank you for the level of detail in where the little parts go...I needed that. Apparently I'm missing the top o-ring...I assume that's not such a big deal if I don't have it?
Sparkplug. I cant say what is holding it up. I would suggest though trying to operate the shift lever in all positions while you disassemble to see if a specific setting (neutral, reverse, or forward) might free it up, in case your shifting shaft is keyed.
great video helped alot! got mine back together but have no visible "tattle tail stream"... i made sure the copper pipe is seated..... i think the water should be coming out of the rear center hole on the bottom cowl?
I cant say for certain, but it sounds likely that the shaft itself or the linkage was rotated perhaps 180 degrees when assembled. Cause it is just inverted right?. But that is just a guess, sounds like something simple in the linkage that still works but is just rotated or backwards.
Man, you have no idea how much this video helped me!! Thanks so much!!! I'm about to try and change the oil in the lower unit. Do you know how, or what kind of oil to use? Thanks so much!!
1. How do you align the splines on the shaft with the power head? 2. How do you get the pick up tube to go into the water outlet on the impeller housing? These can be tricky things if you don't know how
unwinsis I dont recall any issue getting the spines to align. I do recall some fiddling to get the tube to line up during final assembly. I didnt have a firm method. It was more tilting and slowly putting them together until it all fit. It took multiple tries.
Far Reach Engineering I'm having a lot of trouble, can't get it to close tight and even when the the shafts are in enough to engage, its always in forward gear no matter where you put the shifter
unwinsis I dont have a direct answer, But a couple things you might try as options. Your shift lever and the transmission shaft itself may be out of sync. That being like the lever is in forward, but the shaft is set in reverse. You might want to try setting either your lever or the the transmission itself to a different position. For instance you should be able to rotate the transmission selection shaft by hand. It should rotate one direction for forward. The other direction for reverse. Once you confirm where you are on the transmission. match that position on the lever and then assemble. For instance try neutral on the lever and neutral on the transmission. Forward and Forward. Backward and Backward.
+unwinsis I'm sure you've figured it out by now, but here's the issue I had. On my 1998 Merc 5hp, and others with a similar build, the drive shaft can be a real bugger to get back into place. The reason for this is that the drive shaft tends to miss the tube that it's supposed to go into. This is made worse by the task of aligning the shift shaft with the shift shaft clamp. This process causes the drive shaft to go in at an angle. When the drive shaft misses the tube, it will go up into the housing to the SIDE of the tube. Then it will go no further when the lower end has about two inches to go before the two halves are mated. If this is happening to you, I suggest you take a flashlight and carefully make sure the end of the drive shaft is heading toward the tube while aligning the shift shaft. I finally gave up and took the shift shaft clamp OFF and just concentrated on getting the drive shaft where it belonged. I was able to attach the clamp with a pair of needle nose pliers through the side port that is provided for loosening the clamp. I Hope this makes sense. It will to anyone who has spent the hours of frustration that I did trying to figure out why my drive shaft would not go all the way in!
If you don't see water of some sort coming out of the engine, then that is a problem. Might also want to insure the water intake is not plugged. but either way you need at least some level of water running through. and Thanks.
Hey, I have a 4.5 hp longshaft of similar age.. your video was the closest I could find to something I could use for refrence... do you know if my engine is the same what year is yours?
Sorry to say I dont recall the year. There are a lot of mercury fans out there. They might be able to spot it, or tell you more about your engine if you post a picture. I would imagine that if it is also a mercury of similar era and size it would have a similar water pump housing setup, with just different size impeller based upon hp output.
Nice video thanks. I bought a used 1960's Mercury 7.5hp and just fired it up today on a lake....soon as I started it up, the pee hole was putting out water for about 5 seconds. After that, there is a tiny trickle coming out and I ran it for a while. Do you think that is a clog or impeller? Thanks
Hey far reach, just wanted to thank you since I have the same exact outboard motor and I need to do my impeller asap. But I have a couple questions... 1 did you have to drain the lower gear oil? To do the impeller? And how the heck do you shut off the motor because it doesn't have a killswitch?!?!
No. I did not have to drain the lower gear oil to change the impeller. If you have the same engine, you wont need to either. The pump is not housed within the gear oil As for shutting off the motor just turn on the choke. That will cut the engine. Thanks for the positive comments. Hope this helps;
Nothing special that I can think of as a tip on that part. Other than perhaps having a helper do the assembling so that you can try to gauge if the pipe is lining up or not. Dont want to force it shut if it is not lined up correctly. I do recall I used my fingers to hold it near the target by feel while assembling, but there always was a point were I had to let go, pull out my hand and give it a try and see if it fit. It definitely took more than one try to get it lined up right.
Thanks for the zip tie trick.....i just did it on an old Mercury 9.8 (model 110) BUT i stumbled upon a problem when i reinstalled the lower unit.......now my gears are really weird because when i put it in reverse on the lever it´s in forward position at the prop and forward on the lever makes it go in reverse at the prop,neutral works fine.Do you have any idea why it does that?I have tried different positions but the shift shaft has only one way to fit(neutral)
Hey, Question, I put the new impeller in and started up the engine, it was just pushing air up top so i took apart the lower unit again and the new impeller that I put in was destroyed. Have you seen this? 1) what was the easiest way you got the old one off? I had to drill my first one out? 2) when your impeller sits in the grove is it completely center in the pump or did it sit to one side?
Make sure when you start the engine that it is in the water when you start pulling the cord. If water doesnt get into the pump before it really starts up, it will just have dry friction heating up the rubber pump and it will over heat the rubber and the impeller will fail. as for the two points: 1. I used paint can openers. They have a 90 degree hook which i could use to pull up the impeller in line with the shaft. 2. it will sit to one side of the housing.
Far Reach Engineering Thanks! Was able to get it working. Fit perfect the 2nd time and spit water. Question, what is the tube on the starboard side of the engine for. The tube that I am questioning is the one right next to the drain port that spits out the water. The openings are tiny and there isn't much going through there. Per the diagram online that I saw, it is called a bleed hole/bleed drain.
what is the serial number on the motor? I have a 4hp with a 3534018 serial and I'm trying to make sure i get the write impeller. I already tried one, but I don't think it was the right one. Also, there was no "key." Suggestions?
FarReachFR, From the video, is that a late 60's Merc 39? I have a '68 Merc 39 I am trying to get the water pump replaced, but it is giving me a lot of issues binding up. I removed the two bolts that hold on the lower unit, and it slid down about a eighth of an inch or so. It now hangs up on the shifter rod somehow, do you have any thoughts or recommendations as to what it could be? Thanks, sparkplug781.
hm. that is a tough one. Hard for me to say. Not sure the space or elements involved. But first, if it is not interfering with anything else, I would consider just leaving it and buying a new one.
Myself I purchased the impeller parts at my local Mercury dealer. Might want to check to see if there are any local to you, or if there is a marina that might be able to order one in. Ebay, is my favorite for odd parts.
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thanks for the reply. Found out a couple days ago it was a clog. Running like a champ.
That can be frustrating and for me it did take several tries. One thing I did that helped was I applied a small amount of grease to the key and that helped "stick" it in place while I put it all together. You could potentially use another light temporary adhesive to hold it in place, but for me the grease was something that was safe for the system and gave it just enough stick to get it together.
Great explaning the process im needing how to get at the lower. Unit as well. Your daghter likes to help cute.
I very much appreciate your posting. The 4.5 that I have had dislodged a piece of its impeller, sending it up just to the top of the copper tube/ rubber grommet at the intake of the water jacket, where it promptly melted, and occluded the water delivery tube! Wow! Who knew with "nano" tech you could get outboard motors to cream themselves like that! ?!? But seriously, I wonder if some kind of VERY low temperature melting "grease" might be a good idea if new impeller doesn't see like INSTANT H2O?
Hi, I think that the Mariner 4 is basically the same? Either way thanks so much for your informative videos, they take away most of the the 'scary bits'. . . If they are similar, I wonder and hope that you might have a video dealing with the gear oil/lubricant and how to replace it. - - Keep up the good work - - Best regards, Dave.
By the way, on my 1998 Merc 5hp, and others with a similar build, the drive shaft can be a real bugger to get back into place. The reason for this is that the drive shaft tends to miss the tube that it's supposed to go into. This is made worse by the task of aligning the shift shaft with the shift shaft clamp. This process causes the drive shaft to go in at an angle. When the drive shaft misses the tube, it will go up into the housing to the SIDE of the tube. Then it will go no further when the lower end has about two inches to go before the two halves are mated. If this is happening to you, I suggest you take a flashlight and carefully make sure the end of the drive shaft is heading toward the tube while aligning the shift shaft. I finally gave up and took the shift shaft clamp OFF and just concentrated on getting the drive shaft where it belonged. I was able to attach the clamp with a pair of needle nose pliers through the side port that is provided for loosening the clamp. I Hope this makes sense. It will to anyone who has spent the hours of frustration that I did trying to figure out why my drive shaft would not go all the way in!
Just as you said, It could really be either of those two. Clog, or Impeller. I would heck for clogs first as the clog is the cheaper fix of the two. Check the pickup screen/pipe and see if it is all clear. If you pull junk out of it and it gets all better, then free fix. But if there is no visible clog you may want to open it up and check the impeller. (or if there is an internal clog.)
Good question. I used some grease to hold the key in place. Any sticky or semi-sticky substance could work. As for which I stuck the key too, If I remember right I stuck the key to the shaft and then slid the impeller over it.
Thanks for de video , been a great help with usefull tip's
Thank you for the level of detail in where the little parts go...I needed that. Apparently I'm missing the top o-ring...I assume that's not such a big deal if I don't have it?
Sparkplug. I cant say what is holding it up. I would suggest though trying to operate the shift lever in all positions while you disassemble to see if a specific setting (neutral, reverse, or forward) might free it up, in case your shifting shaft is keyed.
great video helped alot! got mine back together but have no visible "tattle tail stream"... i made sure the copper pipe is seated..... i think the water should be coming out of the rear center hole on the bottom cowl?
Thank you for your video
I cant say for certain, but it sounds likely that the shaft itself or the linkage was rotated perhaps 180 degrees when assembled. Cause it is just inverted right?. But that is just a guess, sounds like something simple in the linkage that still works but is just rotated or backwards.
Man, you have no idea how much this video helped me!! Thanks so much!!!
I'm about to try and change the oil in the lower unit. Do you know how, or what kind of oil to use? Thanks so much!!
Hmm, i did replace the impeller, but no water coming out the Mercury 4.5 HP.
The old impeller was damaged, but all parts were there and removed.
1. How do you align the splines on the shaft with the power head?
2. How do you get the pick up tube to go into the water outlet on the impeller housing?
These can be tricky things if you don't know how
unwinsis I dont recall any issue getting the spines to align. I do recall some fiddling to get the tube to line up during final assembly. I didnt have a firm method. It was more tilting and slowly putting them together until it all fit. It took multiple tries.
Far Reach Engineering I'm having a lot of trouble, can't get it to close tight and even when the the shafts are in enough to engage, its always in forward gear no matter where you put the shifter
unwinsis I dont have a direct answer, But a couple things you might try as options. Your shift lever and the transmission shaft itself may be out of sync. That being like the lever is in forward, but the shaft is set in reverse. You might want to try setting either your lever or the the transmission itself to a different position. For instance you should be able to rotate the transmission selection shaft by hand. It should rotate one direction for forward. The other direction for reverse. Once you confirm where you are on the transmission. match that position on the lever and then assemble. For instance try neutral on the lever and neutral on the transmission. Forward and Forward. Backward and Backward.
+unwinsis I'm sure you've figured it out by now, but here's the issue I had. On my 1998 Merc 5hp, and others with a similar build, the drive shaft can be a real bugger to get back into place. The reason for this is that the drive shaft tends to miss the tube that it's supposed to go into. This is made worse by the task of aligning the shift shaft with the shift shaft clamp. This process causes the drive shaft to go in at an angle. When the drive shaft misses the tube, it will go up into the housing to the SIDE of the tube. Then it will go no further when the lower end has about two inches to go before the two halves are mated. If this is happening to you, I suggest you take a flashlight and carefully make sure the end of the drive shaft is heading toward the tube while aligning the shift shaft. I finally gave up and took the shift shaft clamp OFF and just concentrated on getting the drive shaft where it belonged. I was able to attach the clamp with a pair of needle nose pliers through the side port that is provided for loosening the clamp. I Hope this makes sense. It will to anyone who has spent the hours of frustration that I did trying to figure out why my drive shaft would not go all the way in!
Yes, now I have. Maybe there is a leak between exhaust and water compartment. The gases are pushing the water back I think. Could that be the problem?
If you don't see water of some sort coming out of the engine, then that is a problem. Might also want to insure the water intake is not plugged. but either way you need at least some level of water running through. and Thanks.
Hey, I have a 4.5 hp longshaft of similar age.. your video was the closest I could find to something I could use for refrence... do you know if my engine is the same what year is yours?
Sorry to say I dont recall the year. There are a lot of mercury fans out there. They might be able to spot it, or tell you more about your engine if you post a picture. I would imagine that if it is also a mercury of similar era and size it would have a similar water pump housing setup, with just different size impeller based upon hp output.
Nice video thanks. I bought a used 1960's Mercury 7.5hp and just fired it up today on a lake....soon as I started it up, the pee hole was putting out water for about 5 seconds. After that, there is a tiny trickle coming out and I ran it for a while. Do you think that is a clog or impeller? Thanks
Hey far reach, just wanted to thank you since I have the same exact outboard motor and I need to do my impeller asap. But I have a couple questions... 1 did you have to drain the lower gear oil? To do the impeller? And how the heck do you shut off the motor because it doesn't have a killswitch?!?!
No. I did not have to drain the lower gear oil to change the impeller. If you have the same engine, you wont need to either. The pump is not housed within the gear oil As for shutting off the motor just turn on the choke. That will cut the engine. Thanks for the positive comments. Hope this helps;
guyzag1 unplug the fuel line will also die the engine out
Nothing special that I can think of as a tip on that part. Other than perhaps having a helper do the assembling so that you can try to gauge if the pipe is lining up or not. Dont want to force it shut if it is not lined up correctly. I do recall I used my fingers to hold it near the target by feel while assembling, but there always was a point were I had to let go, pull out my hand and give it a try and see if it fit. It definitely took more than one try to get it lined up right.
Hey I just did this on the same motor but I don't think I'm getting the water pipe back into the pump housing hole...any tips on that part?
Thanks.
You know what size was the small oring On the top?
Thanks for the zip tie trick.....i just did it on an old Mercury 9.8 (model 110) BUT i stumbled upon a problem when i reinstalled the lower unit.......now my gears are really weird because when i put it in reverse on the lever it´s in forward position at the prop and forward on the lever makes it go in reverse at the prop,neutral works fine.Do you have any idea why it does that?I have tried different positions but the shift shaft has only one way to fit(neutral)
Hey, Question, I put the new impeller in and started up the engine, it was just pushing air up top so i took apart the lower unit again and the new impeller that I put in was destroyed. Have you seen this?
1) what was the easiest way you got the old one off? I had to drill my first one out?
2) when your impeller sits in the grove is it completely center in the pump or did it sit to one side?
Make sure when you start the engine that it is in the water when you start pulling the cord. If water doesnt get into the pump before it really starts up, it will just have dry friction heating up the rubber pump and it will over heat the rubber and the impeller will fail. as for the two points:
1. I used paint can openers. They have a 90 degree hook which i could use to pull up the impeller in line with the shaft.
2. it will sit to one side of the housing.
Far Reach Engineering Thanks! Was able to get it working. Fit perfect the 2nd time and spit water. Question, what is the tube on the starboard side of the engine for. The tube that I am questioning is the one right next to the drain port that spits out the water. The openings are tiny and there isn't much going through there. Per the diagram online that I saw, it is called a bleed hole/bleed drain.
Dan M I don't know why but on a bigger engine I grease up the impeller maybe you should do the same here .
what is the serial number on the motor? I have a 4hp with a 3534018 serial and I'm trying to make sure i get the write impeller. I already tried one, but I don't think it was the right one. Also, there was no "key." Suggestions?
FarReachFR, From the video, is that a late 60's Merc 39? I have a '68 Merc 39 I am trying to get the water pump replaced, but it is giving me a lot of issues binding up. I removed the two bolts that hold on the lower unit, and it slid down about a eighth of an inch or so. It now hangs up on the shifter rod somehow, do you have any thoughts or recommendations as to what it could be? Thanks, sparkplug781.
I have exactly the same problem. 3 times over!! Any ideas?
Where do you order an impeller for this motor I have the same one
If you could send me a link, you would be a life saver.
And also how do you get the top o ring out if it gets stuck up in the power head
hm. that is a tough one. Hard for me to say. Not sure the space or elements involved. But first, if it is not interfering with anything else, I would consider just leaving it and buying a new one.
Another thing where can you buy the parts
Myself I purchased the impeller parts at my local Mercury dealer. Might want to check to see if there are any local to you, or if there is a marina that might be able to order one in. Ebay, is my favorite for odd parts.
Ok thanks I got the part and got back together working great thanks for the video
Great!
Why don't any of these videos show how to get the impeller in over the key? It's an absolute pig!
I think you should use Rogaine LMAO.