Topic: CB750K4 what did I get myself into?

[BrockCB750]

Yeah have the impact driver, no impact bits for this screw head though. Might try it with a non-impact bit. I will try a little heat later today first. Everything on this bike needs PB Blaster and/or heat and/or impact and/or hammer. haha

Thanks for pointing me to the fastener I was missing.

[RAFster122s]

You realize if you have the right size hex you can cut a section off toake your own bit, then a socket to fit the hex shaft. Typically the screw bit holder pops off to reveal a 1/2 inch drive ...then just pop your socket on and bit in place...

Cheater black pipes can also be used on hex wrenches, but I like impact better as the shock often overcomes any corrosion or bond from dried fluid.

[BrockCB750]

Yep, all those options are on the table. I am in no rush so the plan is to soak, heat and escalate from there.

The fork tubes definitely need to be replaced the rust pitting is deep enough.

I ordered the cheap aluminum 4into1 sun rims as well as tires. They were so inexpensive and with a few people having success I figured they were worth a shot at that price.

Those were the first new parts I have ordered. A lot more coming. The goal this month is to get a rolling frame.

[BenelliSEI]

Get the right bit and an impact gun….. I also suggest you put the spring and cap back on before you hit it. If the inside starts to spin it can make you crazy.

I’ve had a few I actually had to drill the head off, to remove. Fingers crossed.

[newday777]

Yup 6" long 6mm Allen socket driver and a hand impact driver or air impact driver is the way to remove the Allen bolts(be sure you have the springs and top folk tube caps in place to keep pressure on the dampner inside that the Allen bolt screws into)

[BrockCB750]

Well, I don't have the correct tools for the job.

Maybe... maybe this is an excuse to get an air impact... haha.

[Mark1976]

   An air impact is nice, its what we've used for years, but the new battery powered ones are a way better investment. I rarely have to run the air compressor now, which is much better on the power bill. Once in a blue moon do I use air tools, the battery powered ones are just easier.

[calj737]

If you have drained the fluid already, then the most likely method for removing those screws is heat. At least a propane torch, preferably a MAPP gas torch. Direct it onto the screw until it gets red hot. Then use an impact driver to loosen.

[seanbarney41]

   An air impact is nice, its what we've used for years, but the new battery powered ones are a way better investment. I rarely have to run the air compressor now, which is much better on the power bill. Once in a blue moon do I use air tools, the battery powered ones are just easier.

for whatever reason, I have found that electric impacts have too much toque and not enough speed, so if you try the electric first, it will usually spin the whole damper rod whether the spring is still installed or not.  Once that damper rod spins, you WILL have to find a mechanical means of holding it.  A small pneumatic impact zaps those allens out every time...but you gotta try it first!

[Kelly E]

Just drill off the heads of the bolts holding the tubes and slides together. The rest of the bolt will come out with your fingers after you pull it apart. They are grade 10.9 not the standard grade 8.8 bolts when you replace them. I can't remember the thread count.

[70CB750]

Just drill off the heads of the bolts holding the tubes and slides together. The rest of the bolt will come out with your fingers after you pull it apart. They are grade 10.9 not the standard grade 8.8 bolts when you replace them. I can't remember the thread count.

The thread should be M8x1.25.

[BrockCB750]

I bought an allen head bit for my impact screwdriver and tried hammering that allen head screw out. Tons of heat and tons of hammer... I got nowhere. It was about time I got an air compressor. So I got one and an impact... they came right off. No issue at all. haha. Its REALLY nice when you have the right tool for the job.

[PeWe]

You won the fight against the stubborn bolt!

Compressor is a must have anyway

[calj737]

Often there is a copper crush washer there, if so make sure to replace it. Also, upon reinstall, antisieze on that bolt and under the bolt head.

[BrockCB750]

So I have the front wheel, disc, hub, etc. Pulled up the service manual to see how I take this thing apart and the page is missing from EVERY upload. I tried 3 different sources. All missing the page. Can anyone help me find page 132?

[BrockCB750]

Well nevermind futher searching led me to this thread which had a pdf of that page:

http://forums.sohc4.net/index.php?topic=71220.0

[BrockCB750]

Score another one for the impact. Saved me twice now. Look at how bad the corrosion is on this thread. Been slow going waiting for tools and whatnot. Getting very close to actually restoring some part of this motorcycle. haha

[PeWe]

From my reprinted paper version I bought on eBay UK.
Living room version. It will never see dirty fingers. Same with Mark Paris book

I think I have added a missing page before in a thread here.

[BrockCB750]

So every single part of the bike is apart finally. Rear hub took a little time.

So I am not very smart on brakes, particularly drum brakes. The hub has an inner layer that the pads press into. What is the material and should I be careful about how I clean it up?



Also for fun, here is my current pile of stuff I need to haul to the dump:



Not everything there is going but most of it. Those wheels are a very sharp rolling tetanus risk.

Looking at this picture reminded me of another question. If the disc brake measures out okay, what are the chances that it can be resurfaced? Just now thinking about this so probably need to do some more searching around here. Its very old but relative to the rest of the bike can possibly be salvaged.

I am getting so very close to starting to restore the bike. Trying to decide if I want to paint the hubs or just clean them up and then I am going to lace the spokes and drop them off to get the tubes and tires put in.

Timing is perfect, sweated through the late summer getting this rust bucket apart and I can take my time during the winter to get this back together.

[newday777]

Yes you can get the rotor resurfaced. And drilled too if you want.

Godfrey's Garage does it(he's a member here)

And Truedisk does it too
https://truedisk.net/

[BenelliSEI]

The inside of the drum is a cast iron liner. Don’t be afraid to tackle it with a good, course sand paper, then a finer one. That looks pretty greasy, get it really clean before sanding.

[HondaMan]

The front disc is stainless steel (18-8, IIRC) so it should resurface with emery paper on a drill, or the like. They seldom warp: I have not (myself) ever seen a warped one. They are so thick they just never overheat. Later bikes have 1/2 as thick discs, and they do occasionally warp (Yamaha comes to mind).

[BrockCB750]

Nice thanks for the advice on the rotor. I might take stab a cleaning it up myself or get it resurfaced if needed.

I am finally done with pretty much all the dirty jobs except the engine cleanup. But, I may pay someone to blast it for me. Spent a long time in the backyard with a bottle of simple green, the hose and a scrubber pad. Rear hub parts were coated in what I guess is brake dust and chain lube. A little time with the brass wire wheel, a little more scrubber pad and then some prep and I think I will be ready for some more paint.

The best news, the restoration has begun! Primered and applied a few coats of matte black enamel to the front hub. Waiting for it to cure and then finish up with enamel clear.

[BrockCB750]

Front hub got new bearings:





Everything is flush in the hub. The collar has a very slight amount of movement after everything is back together. Scratched near the retaining ring trying to tighten it down but nobody will see that. Need to stake it down but wanted to post pictures just in case someone noticed I did something wrong haha.

[BrockCB750]

One wheel done: