73 Honda CB750 Custom Build Part 18 - Oil Pump

cb750 heart surgery welcome to hack a week yep heart surgery on the cb750 the heart of any engine is the oil pump and right here I have the oil pump to this engine every engines life depends on the oil pump the oil needs to circulate through all the bearings and that's the oil pumps job is to regulate the oil flow through the entire engine there are some things in here called pressure relief valves and they have a lot to do with when the oil is cold or hot etc there's some rings in here that need to replace and there's also a pump like a rotary pump that has well it has some specifications and if it's worn past those it won't pump properly and it won't make the proper pressure that is also a very important aspect of what an oil pump does is making the proper pressure if it's too low it's not going to be able to keep up with the demand of the engine and the friction and the heat buildup that's the whole idea behind lubricating an engine is to fight all that heat from friction and the wear on the parts so come on down here a little closer and we'll tear into this oil pump here it is it's not beating right now this is the heart this is the oil pump this gets turned by the internal gearing and the transmission of the bike and that's what turns this and it turns a rotary vane in here we'll take that apart in a minute and you can see just what makes the oil move there's a screen on the bottom where the oil gets picked up this filters out any chunks of anything that might get in here and cause damage or get into the oil galleries we don't want that that could potentially plug up an oil passage there's pressure relief valves here and here we'll get into those in a minute there's an o-ring in there we're going to replace where it bolts to the engine there are three oil passages here each one of those has an o-ring and a sleeve that goes in there and it's held on by three bolts now this portion right here will come off from the base and there's a small gasket or a thin I should say paper gasket that goes between the rotary section and the base of the pump so we need to take out four screws two of them are here two of them are here underneath the screen I've got some pieces of aluminum angle stock on my jaws and my vise so I don't damage anything on the pump and I'm going to just gently clamp this in there now this screen will pop out you can use a small narrow blade screwdriver you could use a pick anything like that you just basically need to get in on the edge and just gently lift up and it should pop out of there this one's been in there for a while so it might need just a little bit of persuasion but it should come out try not to damage this in the process I'm not sure if this part is even still available from some of the Honda parts houses but we've got to get it off so do my best to take it out of there without hurting anything and it's a little tricky it's not really wanting to move too much right now but we'll get there right angle pick might be the call shove that down in here between the housing and the edge and just pry there goes and it didn't do too much damage to it that should be okay I can straighten that out it's bent just a little bit right there I can straighten it out with the players and easily reuse this no sweat now there's four screws that need to be taken out I'm going to use a bit from my impact driver set this is a impact driver set when you strike on this it has a cam inside that will quickly rotate and the shock of the hammer blow will knock them loose but I'm not going to use that I'm gonna see if I can get it like this yeah these aren't too bad I can get these by hand slip this off it's got a couple of little alignment pins right there but there's that gasket I was talking about you can see it right there just a thin paper one so we'll go ahead and replace that but now we can take this section out of the vise and we'll flip it this way now we're going to pull off this part of the housing by the way some of the screws on Japanese motorcycles are what are called JIS screws that's Japanese industry standard this is a Phillips this is a standard Phillips head it's got more of a radius in these corners right here a JIS screw looks more like this it's got a really sharp angle on those corners so when you look at the screw that you're going to take off take a close look at it because regular Phillips won't quite fit into a JIS screw so if you notice that going on you're taking stuff apart stop and go buy yourself a good set of JIS screwdriver bits before we move on any further I want to show you the breakdown of what this pump is all about here's a picture from the Honda manual so if you want to pause maybe do a screenshot capture that if you don't have manual there's your parts breakdown let me zoom in here on the pieces and the numbers on the bottom anyway there it is so this is what we're going to go by what we're going to take apart right now is this section right here so here we go let's just see if maybe we can get this with the ratchet yep I can get these loose okay now this top portion she'll just pop it off and indeed it does there we are there's the heart of the pulse right there rotating yes now let me zoom you in really tight here and explain how one of these pumps works now here's the deal it comes in here where there's a large opening and then what goes on is great at this point you see as I'm rotating around this side we'll be getting larger that's taking up oil right now now there's a piece down on the bottom blocking any further oil from coming in as it rotates around this cam is going to try to close up against here because of the way it's offset now it can go out through the other side as this closes up so see that hole is closing up and squishing the oil out the other side meanwhile over here this hole is getting bigger so it's sucking up some oil carries that much all the way across to the other side squishes it out the other side so as it rotates around it's sucking it up carrying it across the partition squishing it out the other side that's how most of these rotary oil pumps work now where the ware comes in over time is on these two parts because they're always rubbing against each other right here there's a really tight tolerance between that lobe and that lobe and there's a speck in the book where you put a feeler gauge in there to measure the wear on the thing there's also a spec for the the wear on the outer edge so we'll check that out next okay the first one we're going to check is the outer clearance right here between the housing and this outer rotor according to the book it shouldn't be any more than 0.35 millimeters and that would be 13 thousandths of an inch let's see let's just go ahead and try let's try a 4000 so an inch not sure what that isn't metric because it's worn off here but let's just see if we can get that in there wiggle it around a bit barely I can barely get a 4000s in there so that's good to go that clearance is just fine the next clearance we're going to check is the one right here between this lobe and this lobe and it's the same speck it shouldn't be any more than 0.35 millimeter or thirteen thousandths of an inch so let's see let's start out with point zero seven six millimeter which is three thousandths of an inch now the way I found it's best to do this is rotate it back get the feeler gauge started between those two lobes and then rotate up on to it and you should be able to move it back and forth it's feeling to me like that three thousandths just barely fits in there so that's good let's try a four thousands just for the heck of it and that doesn't quite make it so good this oil pump is in great shape very very little we're going on there there's a couple of a rings on these that need to be replaced right here and they seal between this part of the housing and the outer part of the housing if you go looking these up on the early K bikes you'll find that they're they're just not listed they're unavailable well after a little bit of research and some help from the single overhead cam for forum which I will refer to from now on is the sock for forum this part number nine one three zero five four two six zero zero three will work it's four it will come up four I think some of the GL bikes and earlier motorcycles from Honda but it works it's the right size it specs out to the right size and it fits right in there nicely you put it in here and just put it back on there and let's see yep it can definitely feel there's a little bit of interference there it's going to squish that thing just fine so that's the o-ring that you put on there and I've ordered a couple of those up there's an o-ring over on this side too so we need to take this apart and what you have to do is pop this Center rotor out that was screwdriver here should be able to catch it lift it up take that out of there we'll set it here for now and there's a little pin in there that will slide over do you see the pin coming out so it'll come out give yourself enough room here we can go ahead and lift out the other rotor as well I suppose now maybe we don't have to now we'll get in there with some small needle nose pliers and pull that pin out there it is we'll put that over here on top of that rotor and now we can slide this shaft all the way up should be able to anyway there comes so now it's all apart go ahead and take this o-ring off put a new one in its place now it's going to fit a little large but that's okay because it gets squished by this housing right here when it all goes back together so you can see there's two sides of this pump there are two of those same assemblies going on on each side there's one on this side and also one on that side so there's two of those in there let's get this back together make sure the o-ring doesn't get pinched anywhere should go together nice and easy and it does that's all lined up now we can flip all this back over go ahead and put this back in the vise wipe it up now the first thing we're going to do is get that pin back in there so we'll grab that with the needlenose pliers rotate this around where we have room to get the pin in it should be in just far enough where it doesn't poke out the side towards me we'll drop this rotor back in we have to move this around a little bit to do that there we go let's get our other new o-ring drop that on put this back on the other cover a little wiggle there and we're good I think there were a couple of smaller rings inside the unit but they seem to be okay so I left them alone now we'll just go ahead and tighten these up snug get things lined up they're a little bit better now will torque these up to 8 foot pounds or 96 inch pounds using my inch pounds torque wrench let's get them all snug first let's make sure everything is good and not pinching on anything that shouldn't be taking it up a little device pick them up to where the torque wrench clicks eight foot pads now you'll notice I didn't using Loctite on these you don't have to lock tight everything locked tight hasn't been around forever and things stayed together okay without it and these should do just fine there we go that part of the pump has now been redone now let's get back to the housing here we'll lift off this gasket to go ahead and scrape away any gasket material it's on that as well just like we did to the rotor section it all came off pretty easy put all that aside all right let's clean some of this oil off here we're not handling a bunch of greasy mess now we need to get this off we'll go ahead and clamp this up carefully in the vise make sure we're not going to clamp anything critical doesn't have to be screaming tight or anything just snug in there let's get that out of there it's a fourteen millimeter and that's not good that just broke that wasn't very much holding that at all how about that am i glad that happened now and not after I put the bike together you bet your ass I am let's get up close and personal with that I'll show you something I really hope this shows up in the video because right there see that spot that looks kind of dry like there's no oil on it that is the only thing that was still holding this all the way around where it's dark-colored it was cracked somebody over tightened this at some point in time well that kind of sucks that just puts a stop to everything I'm doing right here let's pull that spring out there should also be a little piston down in there let me grab a magnet tool and we're going to pull that out there it is right there see it's got a couple of holes in it the job of this is to bleed off a little bit of pressure as the oil pressure comes up and it maintains the same oil pressure regardless of the temperature and viscosity of the oil that's the idea of a pressure relief valve well now I'm going to get that out of there how do we do that well we just spin it out because fortunately it's not really seized in there well that's just crazy I've got a lot of parts kicking around in these boxes there may indeed be one of those somewhere but I really doubt it and I got a feeling it that's going to be a really tricky part to find let's see which way did that go just like that Wow okay well I want a part son for that in the meantime we can move on all right I've got the housing flipped around here with this side pointing up this is another valve this is called the leak stopper valve pretty sure what this does is if you spring a leak on one of the oil lines the back pressure somehow maybe goes away and stops the flow I'm not sure I have to research that one or maybe if somebody knows about it they can explain it down in the comments let's pull these screws out you can just get the screwdriver on them now whoa Wow just kind of jump right out of my hands there's an o-ring on the backside of this incidentally it's the same sized o-ring as the three o-rings that go on the back of the housing and on all of these o-rings when you see them SPECT out on the parts breakdowns this one's a 15 millimeter by 2.5 millimeter that 15 millimeter dimension is the inside diameter of the o-ring the 2.5 millimeter is the thickness so now you know what all those numbers mean we have a spring we're going to pull out of here a little lightweight spring there's also a piston comes out and there should be a rubber piece of rubber in the end of there it stayed behind let's go ahead get that out of there that piece of rubber goes into the end of this and it seals up against the bottom of that cylinder so that needs to be in good shape and pliable and it is this one's okay I don't need to replace that that still got plenty of life in it so we'll put that aside and we'll get all this cleaned up now with a little bit of parts cleaner and then I get to go on a parts hunt for this little broken sumbitch boy I'm so glad that happened here and now on the bench rather than after the bike was all together because I would have lost all my oil pressure could have happened while I was driving you know of course the oil pressure light would come on but still yeah that's just not a good thought you know losing oil pressure means you're wearing out bearings and such so this is why it's really good to inspect parts before they go back in the engine I am so glad I took this apart and looked at it yeah so that's what you do before you put anything back into the inside of the engine inspect look it over really well and make sure that it's all good before it goes back in no short cuts allowed okay fast forward look at that I found the part there it is it is part number one five one four seven - three zero zero - triple zero and it wasn't that expensive it was maybe seven bucks something like that so got that little sucker let's take that thing out of there and yep it goes right in there screws in there just fine we'll be sure we don't over torque that one huh okay let's put all this stuff back together we'll just do it in a reverse order we get that leak stopper valve put together first let's get this clamped up we're going to drop all this stuff right back in there probably not a bad idea to put a little bit of oil on some of this stuff as I put it back together just so that it's pre lubed a little bit pretty much anything that moves in the motor it's not a bad idea to put a little oil on it just to help it out and this one had the lightweight spring on it and it's got the o-ring on it now this Oh ring these things if you go online and look for these o-rings on the parts breakdown you'll find them they are available they are anywhere between four and six dollars each that's off from most of the Honda websites have a hell of a time getting that one out of there and I look at that price and I said my god that's ridiculous it's just a friggin toe ring why do I have to pay that much money for it well I went to my local old-timey hardware store here Bernie's Hardware here in Aberdeen North Carolina a little town near Pinehurst where I live and they had these o-rings available and you know what they are well let me show you what the price is you see that price how's that let's see should I pay six dollars each or forty-five cents apiece not a real hard decision there so let me get to clean this off a little bit little bit parts cleaner drop another oring in there look at that exactly the same size and because I had the specs from the parts breakdown that I always used I had the exact dimensions and on the little drawer that it came in that's exactly what it was labeled 15 millimeters in diameter so we're going to put this one back together now and those are six millimeter bolts essentially so we can tighten those up do about eight foot pounds maybe a little less I just go by feel on some of this stuff I'm not clicking yet and it's feeling pretty tight and I don't want to chance stripping anything out so I'm going to call that good enough right there it's probably about seven foot pounds okay that takes care of that valve okie dokie we've got this back in the vise and we're going to put a little bit of oil on this pressure relief valve hope it slip and slide a little better drop it in there with the holes going in first put the spring back in and we put our happy little cap on there when it broke before we have to push down on this be careful you don't cross thread it what might actually be a little bit easier is if I just grab a 14 millimeter deep socket and then I can use that to kind of help me get it started not to take the chance on cross threading in there we go I don't have a torque spec on that but tell you what that's not going to be a very tight thing that little bit of metal on there so I'm going to do this one by hand it doesn't have to be really tight and I say that's good enough now if we wanted to check it we could always check what the torque is that I just put on with the torque wrench by backing all the way off to zero since this is an inch pounds torque wrench what's 3 foot-pounds 3 times 12 36 so let's go up to about 40 40 inch pounds and see where that's at okay that's that's 40 inch pounds let's go to 6 foot pounds that would be 72 inch pounds so there's 72 inch pounds that's 6 foot pounds so I'm at 6 let's add another 12 to that seven foot-pounds well okay looks like maybe eight foot-pounds is going to be it there's 85 six seven eight nine ten that's 90 91 92 and 83 92 three ninety four five six 96 inch pounds eight foot pounds so there we go it's just barely turning so eight foot pounds is okay for that whoo all right let's put everything back together we're going to take the pump put it back in the vise and I'm going to wipe that surface clean of any oil and take this section wipe it clean of any oil and we can take the gasket we'll lay it on here like so but that's backwards there we go all the holes need to line up properly I can just look at the bottom of this and tell which way it matches up there's two small holes a big hole etc so that's it that's the way it has to go I can just take a peek underneath and line up those dowel pins through the gasket there we go drop that on now we're going to take these four screws right here that are a little bit dirty because they had some oil on them they were laying on the bench I'm going to clean those off quickly okay let's drop those in those four holes we'll just tighten those up by hand and we'll follow up with the torque wrench torque wrench is still set to eight foot-pounds so we'll just do a cross pattern on these as we tighten them up pigfoot pounds that's that okay last but not least we got the screen to put back on I didn't buy a new one because this one looked like it's totally fine reusable to me so let's see if we can get that back in there I think I can probably just tap it back in place with a dead blow hammer just go around a little at a time work gently yes indeed there we go okay we've got this thing flipped over there's a dowel pin right there one right there and there's one that goes over here but it doesn't really press into that very far so I'll probably put that into the case when I install this but anyway there's three o-rings that go on here one on each one of these like so as I said I'll probably put this one on the bottom of the engine and slide the o-ring over it that's it this thing is rebuilt and ready to go back on to the lower part of the case so let's flip the engine over and install this thing here we are in the bottom of the crankcase again there's a little bit of some gasket material left here I'm going to get that out of the way it's pretty trivial but I want to make sure it's gonna have a really good feel get all that stuff off okay I'm happy with that it wasn't very much all nice and clean now we can put this other dowel pin in right there we'll put the o-ring around that now we're going to drop the oil pump in this gear engages with a gear right here so when you drop it in just pay attention that the gear is engaging okay don't force anything you can always grab the crankshaft and give engine a little bit of a twist just to make sure that everything is okay it looks like it's pretty good right there there goes all of our overhangs are in place now we've got three six millimeter by thirty five millimeter bolts the drop in here let's torque those up to eight foot-pounds just go a little bit snug a lot of time what pounds is not that much now we're ready to put the oil pan out now the oil pan in my mind should be sealed up really well so I'm going to go ahead and put a little bit of the aviation Permatex gasket sealant on there this is optional you know I just default towards adding some because it can't hurt a thing it it's just going to add to the whole process of making sure we don't develop any oil leaks further down the line nice thin coat all the way around I'm going to lay the gasket in there now get the holes lined up same treatment to the oil pan a little bit of gasket sealer all the way around that takes care of that now we'll go ahead and drop this on here let's just give this one more look over everything looks good no chunks of anything in there no no cheerio is hanging out no mouse turds okay now these higher let's see six millimeter by 28 millimeter bolts that go in here there are eight of those that go around the perimeter here let's just get a few of them started here and here there are two different sizes this one gets a six millimeter by 40 millimeter and this one gets a six millimeter by 50 millimeter okay six millimeter bolts anyone want to guess what they torque to that's right eight foot-pounds and we'll do a crosshatch pattern on all of these just gonna follow kind of a make it up myself pattern here five six seven eight nine ten let's check out the oil drain plug here wasn't even tight but it's got a big de Lune when I'm crush washer on there that it looks like it's been used quite a few times for now I'm going to just put this on and tighten it up and once we get a few hundred miles on the bike I'll be changing out the oil anyway and at that point I'll change that to a new one but for now good and snug well that about wraps up the oil pump in oil pan there's a couple of drain plugs that go in here I've got to get the OL rings for those we'll do those later on that takes care of the oil pump and oil pan there's a lot of processes to this whole building of this cb750 isn't there a lot more than I ever realized I've got those oil metering Jets they arrived today in the mail from Mike Rick and thanks a lot for that Mike he's the one that did the head on this and I checked with him look he looked up the records on it it had a mild port job done new valve guides new valves valve job done and that's about it and it's better than it ever was brand new oh there's also valve stem seals installed so that's good big upgrade on the head well that's about it for this week next week we'll get into that hole cam and everything else we'll put those metering valve Zee and get the cam tine and boy we're getting really close now then we can move on to the carburetors pretty soon all right well thanks a lot for watching thanks for the donations and until next time and we'll get the camshaft put on and set the timing on the camshaft but for that Deb times thing I don't know what the hell did I just say

Channel: HackaweekTV

Views: 56,340

Rating: 4.9366088 out of 5

Keywords: electronics, diy, hardware hacking, hackaweek, motorcycles, circuit, automobile, mechanical, cb750, cafe racer, oil pump, honda cb 750, 1973 cb 750, motorcycle, engine, four stroke, 750 four, rebuild, Do It Yourself (Hobby), custom motorcycle, motorcycle build

Id: L-nqD0KxM5E

Length: 35min 50sec (2150 seconds)

Published: Fri Feb 13 2015