Topic: cases stuck together cb500

[haill]

hello trying to get the cases apart on my 71 CB500 have removed all the bolts and followed the Honda manual as to what parts to take off. the cases have a grey gasket compound between the two surfaces which seems to want the top and bottom cases  to stay happily married together. any idea's on breaking up the marriage.
regards from the home wrecker, heart breaker...

[bistromath]

can't recommend this since it's not at all kosher but I took a big wooden dowel and used it as a pry bar between the alternator rotor and the case. not pretty, not recommended, but it worked. you can also get a big rubber mallet and gently thwack the cases around the gasket to try and dislodge them.

[bucky katt]

there is a tool called a case splitter, you might could rent one at a local parts store or tool rental place

[haill]

yes maybe two metal bars placed between the two mounting points at the top and bottom of the motor. then expanding with a clamp till it shears the gasket apart.
Have been doing my share of thwacking with a big rubber mallet but not opening.
did give me time to clean the motor though while waiting for the solution to dawn.
thanks keith

[Kirby]

Haill:  I just did this on my '72 500...I had a seriously siezed motor... no 1 piston welded to its sleeve...destoyed it whilst beating it out so I could get the cylinders off...but my cases came apart fairly easily.  Please recheck all bolts out...tap with a hardwood block and a mallet where ever you can.  Maybe down through cylinders beside the rod ends.  Lay it on its side or hoist it by the upper half, an inch off the workbench, then tap on lower half.  Good luck, Kirby

[gane]

Been there broke that, 1st, recc, research parts book, count upper &lower case bolts & confirm all out. then locate positions of locating dowel pins. and heat general areas lightly (propane is good) 'til spit sizzels on contact.. most cases have prise points (two parallel flats/protrusions) on corresponding case halves... luck G

[bryanj]

Theres a bolt inside the sump pan that gets forgotten, cases always fall apart easy when all bolts out

[haill]

went to sleep woke up and a bolt in sump pump grew in there over night... still cleaning the casing before separating, so things stay clean but that might of been the reason. will give it ago after my coffee and crumpets. thanks very much. Keith

[mystic_1]

went to sleep woke up and a bolt in sump pump grew in there over night...

I hate it when that happens 

Let us know how it turns out.

mystic_1

[haill]

good news the the motor is clean and the cases split apart with some thwacks from the rubber mallet. shown is the primary chain slack in the photos. Is this allot? seems to be. photo also of the cam chain slot where it looks to have removed some aluminum, is it from the factory like this?
to get the primary chain off does one remove the oil pump and drive the primary shaft out with a wooden dowel? don't have the special tool shown in the manual.
thanks for your time and mind. Keith

[haill]

here's the next up date with the case split. the pics show the primary with and without Viagra... or new and old.
the other pic is the grinding of the primary chain into the oil galley of the lower case. looks like it was a ride away from going through or in other words the galley is about this thick. feel somewhat lucky...

[Tnutz]

how many km's on that motor? my rebuilt (rings, stem seals) cb500 has 20000 miles on it.  i sure hope the primary chain doesn't look that bad.  Really wonder why the hell they didn't use a tensioner or have a gear driven one. My GPz1100 was nice cause it was gear driven primary.

[haill]

23000 miles or 37000 kms but the previous owner drove it around most of it's life on 3 cylinders which probably caused it's earlier demise. not sure how long they're supposed to last? but judging by this one, about 5 more minutes...
best thing you could do for yourself is drop your oil pan when your next oil change is due, or if your really worried tomorrow.  have a feel around with your fingers up the track that the primary chain follows along the front of the motor. if you feel any ruff sections in there, your chain has stretched.
the bike is new to me. but when testing after rebuilding everything but the motor, the gears  clunked  when moving between 1st and 2nd. which also could be a sign for you.

[Tnutz]

this one shifts remarkably smooth, (judging by the king and queen seat that was on it, it lived an easy life)  but thats rediculous...30,000 km's and they are stretched beyond service life.

[Tnutz]

i did drop the pan to clean it, but i couldn't feel to much...i do have a spare 550 motor with 48,000km's on it, maybe i should dive in to the bottom end and change the chain for a project.