cb 77 engine stuck???

[brewsky]

L M, the only damaged part i've found thus far is the area where the oil filter shaft goes into the c-case (as shown in the 2 pictures). Oil filter, chain, etc. seem fine. I have not accessed the clutch area yet due to 2 p-h screws that are gouged-out in the c-case cover. as far as "loose" screws i've not come across any of them YET!

Another method is to carefully drill the heads off the screws, pull the case off, then you can remove the leftover studs with vicegrips.
Luckily, there are replacement screws (6mm) available and they aren't subject to the changed thread pitch problem there is with 3,4,5 & 12mm sizes.

[e3steve]

Thank you sir. I'll give that trick-a-try.

Get yourself one of these. Excellent value and works a treat!

[waynew]

thanks fellas! between the 3 methods y'all have mentioned i should have little to no problem.

[brewsky]

There's generally more than one way to skin a cat.

One thing I didn't know for a long time is that phillips screwdrivers and bits are not all the same.

There are old JIS, new JIS, ISO, DIN, and who knows how many other standards out there.

Some phillips drivers are actually designed to "ramp out" in case of excessive torque and that encourages stripping.

The best driver to use is in the OEM tool kit if it is available. If not, make sure the driver you are using matches the fit of the screw exactly....ie goes all the way in the slots with no slack.

For stubborn screws, I use the OEM driver (without handle) and clamp vicegrips to them. I add a little valve grinding compound to the tip to increase "traction" and tap the driver into the screw a couple of times with a hammer. Then give a sharp quick twist while pushing in hard.

Have used the same technique with bits from an impact driver set. Generally they fit more exactly into the screw slot than normal screwdrivers.

[G-Man]

That's the great thing about this forum, learning about everyone's method for solving a problem. I like the valve grinding paste idea, never tried that before.

When I had new Japanese bikes I got some really expensive (worth their weight in gold) Tee handle screwdrivers which worked most of the time. Mine are getting a little worn now so must look out for new ones.

I use a variation of Davo's method but with a small sharp chisel. I create a sharp groove in the edge of the screw head then angle the chisel so that it acts at a tangent to the screw head (near as possible). I'm pretty good at it now but it doesn't work with countersunk screws.

Nowadays, with highly corroded cases, I go straight for drilling the head off. Usually the remaining half of the screw is loose after that.

G

[e3steve]

I'm in total agreement, in every aspect, with both the foregoing posts from Brew & G!

Wayne, if you have the bike's OEM toolkit then that's the driver blade to use (the Phillips 2-point) but it must be in good condition; there's a T-handle in the toolkit to fit over the driver blades, usually a separate item but, in some kits, sometimes is just a slot halfway along in the handle of one of the smaller, pressed steel spanners (wrench). If the tip of the blade is worn then it won't grip in the screw slot (great idea of Brew's, using the valve grinding paste) and the whole wear-cycle goes full circle: the screws start wearing the tip then the tip ruins more screw heads -- and so it goes. Phillips drivers fit the JIS screw heads very well, but if a screw is corroded or stubborn then use the toolkit driver first to break it loose. Snap On Phillips tips have tiny, angled barbs machined into the a/c/w vanes' faces for extra grip.

The Unicorn 2600 Impact Driver from eBay's mrsuperdeals (Rusty Riders) is a great -- and inexpensive -- bit of kit, and the included hardened driver blades fit our screws perfectly

Beware screwdriver tips made by Reed & Prince (45º tip angle -- Phillips is 30º), Pozidriv (extra flutes between the blades' vanes) or GKN SupaDriv (like Pozi but shallower, truncated tip). They definitely will screw up your heads! Pun intended.

[e3steve]

A bit off topic but, just to append, the benefits of an impact driver are manyfold; the grip of the tip of the driver blade is maintained by force of compression; the screw is (hopefully) shocked and turned by the driver's torsional force generated within the very coarse screw mechanism; any corrosion between the bolt and the casing (and the threads) is shocked loose by the impact.

It's an in-expendable tool to have for the disassembly of old motors.