Tilting the engine

[Jukebox Gothic]

I read somewhere on here that its possible to work on the top end of the engine by tilting in the frame. Im just changing the cylinder base gasket and so if its possible to just pivot the engine on the bottom mount this would make things easier. Thanks for any information on this.

[DJM]

I'm interested to hear if anyone has ever done this successfully.

To tilt the engine as you describe you would need to remove or disconnect all of the big stuff, exhausts, air cleaners, or at lease the tubes, drive chain, and gear gear linkage.

You might get away with leaving throttle cables, wiring and clutch cable in place but not much else. You'll need to remove the RH side cover anyway to replace the chain.

Only thing you'll leave in really is the two lower rear engine bolts and you'll need to at least loosen these.

Tilting the engine as you describe involves a serious risk of damage to the front fender, it's doubtful if there is enough space anyway to lift the cylinder head off clear of the long studs

Give your knees a break and get the lump on the bench where you can see what you're
doing.

Incidentally, many years go someone told me that, by turning the whole bike upside down with the wheels facing the sky, it was possible to lift off the lower crankcase and work on the transmission without disturbing the top end of the engine.

I can state categorically that this DOESN'T work, design of the frame and rear engine mounts mean that even with all the bolts removed there isn't enough clearance to separate the two crankcase halves, another lesson learned the hard way!

[G-Man]

Try doing that with a CL77........ :-)

G

[DJM]

G-Man.

The CL77 does have a couple of saving graces.

With care it is possible to remove the top cover from the engine while it's still in place in the frame.

With the top off and more care it's possible to remove and replace the cams, cam sprocket and cam chain too.

The tricky bit is wriggling the cam lobes past the rocker arms, which of course have to stay in place, but it can be done with care.

It's fiddly, but much quicker than removing and replacing the engine to do the job, less chance of damaging the paintwork too.

I did it a few years ago to replace an advance / retard unit (cam sprocket) in an engine which I knew was faulty in an engine in which when I knew everything else was good; otherwise I would have pulled the motor out and taken the opportunity to do a full strip down and inspection.

An option worth knowing about though.

Of course you can't do any of this with a C, CA or CB model.

[Jukebox Gothic]

Thanks for the reply's. I have a CB72 and recently removed the engine and was trying to avoid lining everything up with a full engine removal. I have to replace the cylinder base gasket and thought tilting the engine off the bottom mount with the front on a lift would be easier than trying to move the whole engine around. Chest surgery made this a bit difficult last time and Im working alone.