Topic: CB 750 engine installation on freshly painted frame/ WITHOUT SCRATCHING

[jsaab2748]

This may be old news to some. I learned it here and thought it's worth mentioning. When installing the engine into a freshly
restored frame I found this to be very helpful. First lay the engine on it's side, using cardboard or an old throw rug as padding. Lift the (this is important) TOTALLY BARE frame over the motor, then carefully maneuver it around and onto the motor until all mounting points are lined up. Start as many bolts as you can reach, then turn the whole assy. upright on the padded surface. This proceedure will require a little creativity when building the rest of the bike, suspension, wheels, etc.,
including an extra set of hands, but makes for a flawless engine install when done properly. Doesn't hurt to protect the frame tubes with tape, thin foam etc. before you start too. Much easier to lift a light frame over a motor than a heavy motor onto a frame.

[Hop on a Honda]

This may be old news to some. I learned it here and thought it's worth mentioning. When installing the engine into a freshly
restored frame I found this to be very helpful. First lay the engine on it's side, using cardboard or an old throw rug as padding. Lift the (this is important) TOTALLY BARE frame over the motor, then carefully maneuver it around and onto the motor until all mounting points are lined up. Start as many bolts as you can reach, then turn the whole assy. upright on the padded surface. This proceedure will require a little creativity when building the rest of the bike, suspension, wheels, etc.,
including an extra set of hands, but makes for a flawless engine install when done properly. Doesn't hurt to protect the frame tubes with tape, thin foam etc. before you start too. Much easier to lift a light frame over a motor than a heavy motor onto a frame.

I'll agree wholeheartedly with the above .
but if your in another situation, use  length of clear 1.1/2" inch plastic hose slice it down the middle and cut again to suite the fram section length.
Use Electrical ties to secure the tubes to the frame.
Works a treat.
Dave

[SteveD CB500F]

Is there a best side to lay the engine down?  ie does the frame go over more easily from one direction or the other?

[spitfire]

Hi Steve,
           Am just about to do this, the engine can only go in on one side, if you are sitting on the bike it is the right side, unfortunately it will lay on the nice shiny chrome points cover. I intend to cut some timber to support the engine on the head/barrels and the clutch cover to keep the points cover off the ground. I have carpeted this area of the garage as well (dead posh here) and have an old dented points cover to fit to stop the points getting crunched. Will post some pics of the layout and the "operation", got to pick a day when the wife's out as she panics about my back and I don't want her to see me lift the engine from the bench and lower it on the floor !

Cheers

Den

[SteveD CB500F]

Take lots of pictures!

[Bob Wessner]

I second that. Actually, it would be great if someone were to video their efforts to get it back in the frame. Asking a bit much, huh?

[spitfire]

OK, was very lucky, the 12 year old grandson came around and we did the job in about 15 minutes without a scratch, used 2 house bricks and some pices of wood to support the engine on its side. As an extra precaution covered the one supporting the cylinder head with some carpet. Lifting the frame and aligning the bolt holes was very easy, did not need to protect the frame as it was easy to manoeuver. Highly recommended method, just have the engine bolts ready to go in. See pics.

[spitfire]

More pics

[spitfire]

More

[spitfire]

in place

[spitfire]

final touch, engine bolts

[spitfire]

And finally, thanks to my grandson Dean !

[mcpuffett]

nice pics Den  , keep em coming , nice one to your grandson to ,   mick.

[78 k550]

I knew there was a trick. Thanks for the info. Always nice to have an extra set of hands. I bet he cant wait to ride it one day.

Paul

[Brunow]

Whow thanks! And thank your grandson to! 

[andy750]

Hey great pics and what a great looking engine you have! What did you use to paint it?
Thanks
Andy

[spitfire]

Hi Andy,
           The cylinder head and barrels were removed, soaked in a bath at a local engine shop for 2 days, this got rid of all the oil and dirt plus it softened up the old paint. Then was the long labourious job of removing the old paint and oxidation with a wire brush attached on my Dremel (stainless brush). The crankcases were degreased with kerosene and then treated to the Dremel and wire brush treatment. The head, barrels, oil pan (old one fitted in the photos) oil filter and camcover vent cover were then sprayed with US Automotive (VHT-SP127), and baked in the oven, unfortunately I misread the instruction and baked them for 1 hour at 200c instead of 200f, had to redo them as they went slightly yellow. The crankcases were than masked off and sprayed, did not even try and bake them but the paint was tough enough to withstand handling and oil spills while I put it together. There's another post of mine somewhere with more details and photos.

Cheers

Den

[andy750]

Hey Den, thanks for the info and reply. BTW I just saw your gallery - very cool pics in there of your 70`s days! Very nice!
cheers
Andy

[crazypj]

Anybody else tried it with a complete rolling chassis?
I found its easier to lift engine if frame isn't bare.
Nice looking engine frame combo.

PJ

[chung]

Gentlemen.... and Ladies:
If I had a dollar for every frame that I have seen sawed in half to remove the motor, I'd buy myself a night's worth of drinks. (and I ain't a cheap date lol)
It is a tight fit and does require some finesse but it really isn't Rocket Science to R&R a CB750 engine Assy.
DISCLAMER author has been drinking

#A very little clearance, 1/4 inch or so.
#B no lift point that will give perfect balance for the engine on the jack.

 I'll try to outline it in short fashion, please correct me where needed, I have probably done this at least a hundred times or more but I haven't done it in 4 years now :
#1Remove the Ex studs (duh) and the Oilpan and pump.... The balance point for the complete Engine Assy is somewhere between the front of the Pan and the Oilfilter Boss
#2 Put the bike on the center stand and place the engine on a milkcase next to the bike, lay the padding on the frame.
#3 position the engine as close to the bike as is practical (2X4s are handy for height adj)
#4 lift the engine on a floorjack with the jack being perpendicular to the frame. Lift point will be at or near the alternator.
#5 Someone will need to manually lift the farside of the engine to match the lift from the jack.
#5 Roll the jack Across the bike, Drop the motor and reposition the jack
#6 repeat until you have the engine in position and then lower it into the cradle
#7 and most important PLUMB, LEVEL and TRUE on all axis or you WILL NOT get the motor back into it's home
#8 Add all the stuff that was removed and do a huge smokey burnout to break-in the engine. This happens quickly and if it's gonna break. do it now. Pussyfooting around will not add to the life of the engine, it will only lower the compression and increase the blowby

It's 4:20AM, I have to go outside to take a short "break" now

late

CHUNG
PS.. practice a few times BEFORE you paint everything

[pablo78cb550]

that exactly how i got my 550k motor in. worked perfectly. i thought i'd sound foolish if i post that install.

[seebee750]

I did it my way

[seebee750]

more

[seebee750]

1 more

[seebee750]

(Paint engine and frame first)

Slap the wood to it ,roll it on its side, stand over the engine with the frame and lower the frame. Install all engine bolts, roll it up right.
 Reverse order for engine removal.