FREE SHIPPING ON ALL U.S. ORDERS OVER $39.95*

VIDEO: Triumph 650 Motorcycle Engine Disassembly & Rebuild Part 8

This is the eighth part (check out part seven here) in our extremely popular video series in which Todd Muller, Head Motorcycle Tech here at Lowbrow Customs, disassembles a unit 650 c.c. Triumph motorcycle engine and rebuilds it. In this installment Todd gives you a step by step process on putting your sludge trap plug back into your flywheel, installing your rods back onto the journals using new plain bearings, installing your cams properly, installing your flywheel into the the crank cases and sealing your two crank case halves back together.

Check out the Lowbrow Customs YouTube channel to check out all of our videos. We spend a lot of time and effort creating motorcycle how-to videos, product reviews and event coverage for your enjoyment, please let us know what you think. Click here to subscribe to the Lowbrow Customs YouTube channel and stay in the know!

You can read a full transcription of this video below:

Hey, guys. In this installment of our Triumph 650 Engine Rebuild series, we're going to go ahead and get the crank ready to go in the crankcase and we'll get her installed along with the cams and get her all sealed up. Once that's done, things will go very smoothly.

We got our sludge trap all cleaned out. Well, we have to put the plug back in. Something very important when reinstalling your plug is this plug needs to sit pretty much flush with this surface here. The reason why is because there's an oil hole at the bottom of the threads. If you run the plugin too far, it can block that oil passageway and that is pressurized feed oil, so that could cause a problem.

You want to pay attention when putting this in. You don't want to go below the surface and if you just come on over here, we'll take a look down in the hole in the sludge trap cavity and you'll see that hole that we don't want to block. See it right there, see how it's right at the bottom of the threads? If you were to measure the thickness of this plug as opposed to the depth of where it's at, you would see that putting it too far in can cause a problem.

Okay, we're all clean there. We'll go ahead and just put just a little dab of Loctite on here. We do have a sludge trap plug available on the website that has a hex versus this. If the plug's in good shape, I don't mind reusing it. You may also notice if you are purchasing an aftermarket plug, if you didn't get it from our shop or even if you did get it from our shop, you may want to check how thick it is as opposed to the original stock one.

It should be a nice tight fit like it is. I could see my Loctite spreading around the groove nicely. I just put one drop on there, I didn't glob it on. There are just about there now. Now, that's flush with this, so we're not going to block that internal hall. Got some Loctite on there. The factory, I also put a punch mark on here to keep it from loosening and we'll do the same. You don't have to get crazy there. Okay, plugs in.

Next thing we need to do is we need to make sure the journals are as clean as they can possibly be because that's where the new bearings are going to ride. You really don't want any type of dirt, anything in there. It's got to be nice and clean. I'll take a blue shop towel, a little bit of brake clean. If you're using towels that produce lint or leave residue, you just want to take a look at it before you put your rod on and make sure you're not leaving a piece of something on there. See that? That's got to be as clean as we can get it.

The other thing I didn't say at the beginning but I'll say it now, I like doing this operation, installing the rods and doing the sludge trap in my vise with these soft jaws in here. It just makes it much easier to work with the crank because if you got it on the workbench, it likes to roll around and you'll see in a minute here when we go to put the rods on how much easier it is to have this securely fastened here.

Once again soft jaws, you don't want to put your output shaft on your crankshaft in advice that has grippies or you'll bugger it up. Okay, we got the journals nice and clean. Now remember from earlier when we took the rods off, we marked them with a sharpie, sludge trap out. That means this rod goes on this journal with this facing out. Since I'm ready to put it back on now, I can go ahead and wipe that off or I can do it after I put it on. It really doesn't matter.

Once again, wear patterns. I just like putting things back where they came from. Okay, we've got our new rod bearings. These are what's called a plain bearing. You don't want to open these or mess with them until you're ready to install them. Plain bearing, shell bearing, whatever you want to call it. Once again cleanliness is next to godliness here. You want to keep all this stuff as clean as possible. I believe we did talk about if your standard or oversize, these are going back together standard.

Another important thing in a second here after I install those bearings on this rod, I'm going to use some of this assembly lube before I put it on the journal so that it's got some oil before- when on startup, you don't want to put this on there dry. You don't want any oil on the backside of this bearing. We'll show you here, we'll go ahead and take this cap off. I can see since I wiped that off, there's like some streak marks on here. Once again, that's going to face up on the crank.

Okay, also a good idea to clean those off. Now, it is possible to put this cap on backwards. You may notice there's a groove there and that will locate this bearing. You notice on the bearing, there's that little tang. We'll go ahead and pop one of these in here and show you what it looks like when it's installed. See how the tang meets up with that little slot on the rod cap. Both of those are going to be on the same side. Go ahead and install this other one on the rod.

The other thing I like to do when I'm installing these is sticking up a little bit on that side. I try to get them as even as I can so that when the two go together, it's not going to push it. There we go. You can look down this and see that that rod bearing is even with this surface where are the two pieces meet together. Once again, there's our streak marks. That faces up, both of those are going on the same place like so.

The next thing I want to do is I want to put some assembly lube on here. A nice bead like so. Some on the other one. Now we're ready to put the rod. I'm just going to slip that on like so. Put your cap on like so. These are locking nuts. I'm just going to put a dab of red Loctite on this and then we'll tighten those up evenly. I'm going side to side, kind of getting them cinched down a little bit because we are going to use a torque wrench on them in a sec here.

You always want to make sure that everything's spinning freely as you're going along here, if something's not spinning freely at this point in time, there's a problem. Okay, torque spec on these is 28 foot pounds. I've got my torque wrench set to about 15 for the first. There's 15 on that one. There's 15 on that one. We're still spinning good. I like to bring it down evenly. I don't just want to go 28 on 28 because it's just the way I do it. Just do it this way, it works better. Instead of doing three steps, we'll go up to 28 now because we've got them pretty even. 25, 26, 28.

Okay, we're going to go back and forth now, it's not quite there yet. There she is on that one there. There she is on that one there. There it is. It is spinning nicely. Okay, that's all there is to it. Now we can go ahead and put the other rod on. Once again we marked this out that means it's facing this way, for when we took it off. We still have an old bearing left on here, so we'll get that off here and get this cleaned up. Then, we'll give you some close ups of the new shells on here.

Okay, got the second rod ready to go here. Once again outs facing down, or out- down and out. Once again, both of those lining up.

All right. Time for the torque wrench.

There you go. Making sure it's nice and free. That's it. Flywheels ready to go in the crankcase. Okay, I've got my crankcase on a couple of pieces of wood here. We'll go ahead and take this half off and the reason I put it up on this wood is because once I slip the crankshaft in, the shaft is going to need someplace to go. That's why it's up on the wood. Basically, what I'm going to do is I'm going to go ahead and put the left side bearing on the crank which I've flipped that over in the vise so now the other side is facing up.

I'm going to put the left side bearing on the crank and then I'm going to put the crank in the case. I'm doing it this way because we have the earlier type breather system where we have this pipe and in here is the window. The reason I'm doing it this way is because I have this that engages with the end of the cam and that'll get dropped down in there along with this spring, the end of the intake cam engages this little thing here.

The reason for doing it, putting this side together and then putting that on top is because as you're sliding this piece on, it'll engage with this cam bushing. You have to make sure that the end of this is indexed with these two little tangs on there. If you're doing it the other way around, it's a little bit harder. Later, your crankcase doesn't have this little window thing. All right, left bearing.

When I took this bearing out of the box earlier in the series and in the last part we installed the raise in the case, I basically marked it so I wouldn't have to think about because you don't want to put this on backwards. If you notice, if you look at it, it's different. There's this little portion of the cage here, it's different on this side. I basically marked it in and out. This is going to face in on to the crankshaft and this is going to face out so when it goes into here, that's going to be down like so.

You also may remember how we had to remove this bearing with a puller. Sometimes they slide right on, sometimes they don't. Once again, I've marked it in and out. Not a bad idea if it's going to be a little bit of period between the time you take it apart and put everything back together. Once again, as with any very tightly fitting bearing, you want to get that sucker started as straight as you possibly can and this one acts like it does not want to go on there, that's trying to start.

Well, it looks pretty straight. What we're going to do is we're just going to take a deep socket and we're just going to send it home with this. Once again, any time you're doing something like this to a bearing, inside raise is not going to hurt this. Never pound on the outside of it. I think we need a bigger hammer. There she goes. See, it was tight but not so tight that it didn't go on nicely by just giving it a little help. Okay, bearing seated on there.

One other thing I found sometimes makes this a little bit easier going into that crankcase, rather than trying to muscle this heavy old crank and bring it over here and stick it in there because this bearing has to go in this raise absolutely perfectly straight. If it gets cocked one way or the other, it doesn't want to go together. Basically, I'm going to leave my crank in the vise and I'm going to go ahead and slip this over that because it's much easier to do it that way.

Then, I'll go ahead once this is in there, I'll take the whole thing out of the vise and transfer it over here to the wood in preparation for putting the cams and the other half of the crankcase together. Let's give it a shot and see what happens here. Obviously, the rods have to go through here. It's going but she's a tight one. All right. Looks like she's seated on there. Now, I don't want my rods banging against the crankcase while I move it around, so I have got some pipe insulation here. I'm just going to cut a couple pieces.

Put this over the rods to protect them while we get ready to put the rest of this together here. All right, now we're going to go ahead and transfer this from the vise over to here. Okay, we're going to go ahead and put the cams in now. We'll start with the exhaust cam. There's some lube on there. Okay, that's nice. Obviously, the exhaust cam has where the points go. This is the intake cam. Then let's not forget our breather window. That gets dropped down in there first. We'll put just a little bit of lube on there because we can.

What I'm going to do now is I'm going to go ahead and turn that window so that the tangs are facing like this. I'm going to put the cam in with these, the same. Once again, we'll get some lube on her there. Don't be shy with the assembly lube. Remember everything's all dry. There, I could feel it. I could feel it go down in there and hit those slots, how that's spring loaded now. See, it's hitting the spring and then if you turn it, it's turning that window where I showed you earlier.

Now, it's possible when you go to put the other half on, if everything's not lined up down in that bottom that you could have an issue. There is another way that you can check that is to put a piece of hose on this breather and open and close it using the cam and blow on it. That should let you know that everything's okay there. I can tell that it's it's got that little bit of spring action. It's turning that breather down in the bottom of that hole.

Now, we're ready to go ahead and put some sealer on the crankcase it has and get the other half on there. That will be the crankcase assembly. We'll let it sit on its side here for the glue to cure for about 24 hours. Even though this is non-drying, I still like to let it sit like this for a while because if a little bit of sealer comes out the edges and you flip it up on its side, it can get stuck on here and it makes kind of a mess.

Let's get some sealer on her. I like putting the case sealer on with my finger. Nice even bead. Want her to seal, we don't want to oil the leak out through the crankcase. Careful not to get it too close to into the holes where the through bolts are going to go or then, you'd get it all over your bolts. I'm actually using some Yamabond. We have Threebond 1194 on the website, same-- Basically, just about every manufacturer has their own version of this sealer.

Basically, it's a semi-drying liquid gasket. Used on a lot of different motorcycles on the crankcases. Harley has their own flavor. There's Yamabond, there's Hondabond, you name it. Good stuff, this will do the job. You really don't need to overdo it on this stuff, just want a nice then bead. Once again stay away from the holes. Okay, we've got a nice bead of sealer on both halves of the crankcase. We're going to go ahead and introduce this to this.

The next fun part is the fit of this center bearing too this is generally pretty tight. Kind of like the same as the other side. We're just going to-- Darn it, hang on. There we go. We're going to hope for the best here. So far so good. Looks like it's going into that bearing okay. Our spring actions kind of gone now because the cam's hitting this, but I think we're good there. A little bit of persuasion there. Looks like it's a little bit uneven right there. There she goes. Look at her. Look at her, she's coming together, gang.

Looks pretty good. Okay, I'm not going to mess with my cam just yet. I'm going to start some crankcase bolts and then I'll double check that my cam's good. We'll hope that it's right because if it's not, then it means take it back apart and clean all the sealer off it. We don't want to have to do that. Here's my bolts. Go ahead and start with the stud and I didn't say anything, but I put that stud back in the case. That helps guide the whole thing.

We'll start and get that one on there and then, this long three bolt goes here. Okay, I'm just snugging that up. I'm not cranking anything down. One thing about doing it this way is it's kind of difficult to get these three bolts in, but we'll make it happen here. Okay, now, we have this longest bolt. It's going to go on the top right here because this is the one that also has the exhaust L brackets attached to it. We got just a little gap there, so let's see if she sucks up here. Look at her go. Look at that. It's a beautiful thing. Okay.

We'll go ahead and there's our spring action. I'm pretty confident on my breather installation. We can get to this, let's just move this stuff out of the way. We'll spin it around here. Then we've got one bolt here, one bolt here, one bolt here. Remember when we took it apart, the small hex one goes here for access with a wrench. The longer one goes here. It's spreading in okay, but it's not going by hand like it should so we'll get a ratchet on there.

We did check all our threaded holes on our crankcase before we started assembly, right? Okay, that one. All right, I got the other three in there. We'll go ahead and go around and snug them all down now. Then, once we get them snugged down, before we put the final tighten to them, we just want to give this crank and rods aspin to make sure everything feels beautiful. We still need one for there.

Since these are double-ended, in other words, there's threads on both ends, what I do is as I'm tightening them down, you may need to loosen or tighten one more than the other so that you end up with the same amount showing. It just makes for a neater job, it looks better. See, like this one. This one, I need to throw this one off just a little bit. There we go. In other words, you don't want way more of one sticking out than the other. That's pretty good right there.

Spin around, tighten the other three and then, we're going to give our crank a spin. Okay, yes, look at her go. That's what we want to feel. Nice, easy, round and round she goes. Feels very nice. That means nothing's binding, nothing's caddywhompus, everything's good. Well, now, we'll go ahead and final tighten all of our crankcase bolts. We'll be done with the operation for today. Then, next time, we'll flip her back on our side, start putting our timing gears on, and a whole bunch other parts. [cheers] Hope you enjoyed. See you next time.

Leave a Reply
  •