Topic: Finally putting the engine back together! ...now where do I start?

[drumstyx]

Just received the head, last part I was waiting on, so it's time. I've heard it can be easier to get the top end together first, then build it upside down. Since the bottom half of the crankcase is what came off to open it up, it does seem to make sense to do that. But then, do I torque down to the top end before buttoning up the bottom?

I have the bottom end somewhat together -- that is to say, it's all there, and all the mechanisms and linkages work and are lubed with assembly lube, but it's not bolted up or sealed at all.

Just curious if anyone has any words of advice. I'm sure the various books I have (Hondaman's, Clymer) have at least something to say about it, but I'm definitely interested in experiences.

[540nova]

No one more experienced than Hondaman, follow his book.


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[754]

Start at the bottom, then work up..

[Bodi]

Assemble the bottom cases first upside down - transmission, primary shaft, crank plus primary and cam chain in place, get the case bolts and studs torqued. Flip it over and assemble the top end. I install the alternator, switch wiring, oil pump, shift mechanism, clutch, and side/sump covers last.

[MikeSimon]

I assume the engine is out of the frame. Putting it in, I found it the easiest to lay the engine on the side and then putting the frame on it, rather than trying to hoist the motor in.
This being said, I usually do not assemble components/covers to the engine that could get damaged during this process and can be installed after the engine is in the frame.
Have not tried this on the CB750 as I am not there yet, but it worked well on several other bikes I did.

[PeWe]

Most manuals show as Bodi wrote, upside down. Tighten most of the bolts must be easier too this way.

I have always done it the other way, everything in bottom case, top case with final shaft  hanging in the drive chain oiler plate.
This is a little bit thrilling to be sure that the 3 half rings on clutch trans shaft are located properly and will not fall off when mounting the upper case.
Plus is that the gear shifting mechanism can bet tested before upper case is there.

Clutch can be mounted when engine is in bike and drive chain on, 5:th gear in and easier to torque clutch center nut

Wrap frame around engine is the easy way...

[Bodi]

It doesn't matter which way up it is, whatever's easier. I can't imagine doing the barrels/heads first though, but I suppose it could be done?
An engine stand that lets you spin it is really nice once the bottom cases are together.

[Medyo Bastos]

good work, sounds like you need to have a drink before you do anything else 

[Phinn]

1. Use a good torque wrench.

2. There are two oil seals that should be in place BEFORE you seal the case halves: the large one that goes behind the front sprocket (the "countershaft" seal), and the one toward the front at the end of the crank. It's difficult if not impossible to install those after the case is closed.

[przjohn]

Is there ANY manual that doesn't assemble the bottom end first?