Topic: 1972 CB750 Four K2 -- Rebuilt to NEW OLD STOCK -- PIX ON PAGE 50

[edwardmorris]

Paranoia isn't always a bad thing. This thread scared me like hell http://forums.sohc4.net/index.php?topic=132523.0

Rushed home and washed the frame down, what a nightmare that was. Environmentally friendly cleaner = water and you scrubbing the life out of yourself. Took a very close look for rust holes and for the most part, rust seems to be only on the surface. Checked out the trouble areas where frames rust through and all is good Its the one thing the PO didn't lie about, this must have actually been always indoors. Frame cleaned up nice out of all this, small enough to fit in the back seat of my car when I go to the welder.

[HondaMan]

Paranoia isn't always a bad thing. This thread scared me like hell http://forums.sohc4.net/index.php?topic=132523.0

Rushed home and washed the frame down, what a nightmare that was. Environmentally friendly cleaner = water and you scrubbing the life out of yourself. Took a very close look for rust holes and for the most part, rust seems to be only on the surface. Checked out the trouble areas where frames rust through and all is good Its the one thing the PO didn't lie about, this must have actually been always indoors. Frame cleaned up nice out of all this, small enough to fit in the back seat of my car when I go to the welder.

What happened to the 2 lower steering head frame tubes?

[edwardmorris]

What happened to the 2 lower steering head frame tubes?

PO had chopped them off unfortunately. ilbikes/Gordon hooked me up with a custom kit along with new tubing and angle iron. Just waiting for my preferred welder to free up some time for me to get it installed

[HondaMan]

What happened to the 2 lower steering head frame tubes?

PO had chopped them off unfortunately. ilbikes/Gordon hooked me up with a custom kit along with new tubing and angle iron. Just waiting for my preferred welder to free up some time for me to get it installed

Ah, good. Gordon's kit is trick!

[edwardmorris]

Yep! A bunch of members were helping me out when I was new here and they mentioned I could try Gordon's kit. Since I didn't have the tubing that was chopped, Gordon called me, explained how his kit works AND got me everything I need to make it work on my bike. He also hooked me up with a nice set of  JIS drivers which I think is a must have for anyone working on these machines. What a difference, the rusty cruddy screw came off in one try! Can't thank you guys enough!

[edwardmorris]

Another good thing about the frame scare, look what fell out of it when I turned it upside down! Not sure where it was hidden, its the battery strap. One less thing to buy later.

[calj737]

Edward - before you have that frame welded, have it soda blasted. It will strip to bare metal and done so using non-abrasive media. You can then wash down and wipe the frame with a well-soaked rag with WD-40 until welding. Then, before powder coat or paint, wipe the frame with acetone or denatured alcohol to clean it. Makes everyone's job a lot easier, and your welder can see everything clearly. Besides, he has to grind the factory paint off anyway to weld in the repair areas.

Soda blasting can be done in any temp, outside. It's the bee's knees for cleaning up stuff.

[RRRToolSolutions]

Edward, I'm glad I could help. I knew you were going to like those screwdrivers, the way they fit the screws is so impressive.

I wanted to weigh-in on the welding/blasting/sanding sequence. The person welding the inserts into the frame will need to clean and prepare the areas around the welds. I'd have him get both sides even (identical lengths) and then 1) measure, 2) fit, 3) confirm, then 4) weld. I personally would want to have these welded in first and then blast. You'll want to remove the button bolts from the joints so you don't remove their finish when you blast. All parts of your frame will then be blasted including the new frame joints - ready for fresh paint or powdercoat. If you do blast before welding, be sure you've plugged the tubing so as to prevent the media from getting inside the frame.

I'm looking forward to seeing the end result. Remember, I'll be happy to take a phone call to step through the process of repair. Just PM me for phone details.

Best Regards, Gordon
www.rrrtoolsolutions.com

[edwardmorris]

Thanks Gordon, hopefully if the snow lets up, the weld shop will be open next week and I'll get it done.

Made some more progress today and a tiny bit last night. Was able to take apart rear brake shoes with a homemade stretcher. The brake cam was really jammed in there and didn't look very great. Hopefully it will clean up nice. It all came apart with a bit of whacking with a mallet here and there.

[edwardmorris]

And next, probably the most grueling task so far in the build, those damned old bearings. They DID NOT wanna come out. Casualties include two screwdrivers and a full length of broom stick. But I got them all! I followed the Hondaman's book method, just backwards. I took the left side bearings out first because that's just how it worked out. Drove it out with a screwdriver, but it had to be sacrificed.

[edwardmorris]

The collar ear bent up badly, will have to flatten it out again. Once the left side bearing was out, there was plenty room to insert a wood dowel made out of an old broomstick and just banged it outta there. That particular dowel was destroyed.

[edwardmorris]

Rear wheel was mostly the same story, did it backwards again, lost another screwdriver and dowel. The sprocket holder, one would think this would be easy, turned out to be the worst. Dowels didn't cut it, so had to use a ratchet extension padded with shop towel to bang it out of there. Pix and post make it sound quick and easy but believe me, this was a PITA and took me a good three hours to get them all out. Then again, I don't entirely know what I'm doing Shop towel art resulted.

[Terry in Australia]

I haven't bought Mark's book mate, but that doesn't look like a good way of removing wheel bearings. Check this "tool" out, it takes around 10 minutes to make, and will remove your wheel bearings in around 30 seconds each.

I didn't want to destroy the wheel bearings in my wheel, and with this tool you you won't damage the bearings, and you can re-use them if you need to. Cheers, Terry.

http://www.instructables.com/id/2-Motorcycle-Wheel-Bearing-Puller/

[edwardmorris]

I haven't bought Mark's book mate, but that doesn't look like a good way of removing wheel bearings. Check this "tool" out, it takes around 10 minutes to make, and will remove your wheel bearings in around 30 seconds each.

I didn't want to destroy the wheel bearings in my wheel, and with this tool you you won't damage the bearings, and you can re-use them if you need to. Cheers, Terry.

http://www.instructables.com/id/2-Motorcycle-Wheel-Bearing-Puller/

Thanks for the tip Terry, but I managed to pull all of mine out intact, except for one which i got really frustrated with (tools are a different sad story ). I was planning on throwing these away anyway since they weren't rolling as smooth and had a lousy "step" here and there in the revolution. I looked at the tool DIY you posted and at the very end it has this.

"DISCLAIMER: THIS WILL DESTROY THE BEARINGS. NEVER APPLY FORCE TO THE INNER BEARING RACE WHEN TRYING TO SEAT THE OUTER BEARING RACE OR VICE VERSA. THIS DESTROYS BEARINGS. DO NOT USE THIS TOOL TO INSTALL NEW BEARINGS.

Destroying the old bearings doesn't matter as the whole reason to remove bearings is to replace them."

Anyway, what I do have ideas for is a DIY bearing driving tool, I'll post pix when I rig it up and BEFORE I use it just to make sure my shiny new SKFs aren't destroyed during installation. I went with the 2RS replacements just so I don't ever have to do this again.

[Terry in Australia]

No worries mate, I didn't read the disclaimer, but that makes sense, "side-loading" bearings isn't a good thing, even though my bearings came out in perfect condition and I'd have no hesitation re-using them.

The point I was really trying to make is that the removal process you used that you said took you several hours is about the worst I've seen, and if it's in Mark's book, well that's another reason for me not to buy it. With the tool in the link I posted, it's truly a 5 minute job.

There's no trick to replacing the bearings, so don't bother making a special tool, all you need is a similar sized socket to the OD of the bearing so that you can tap the bearing in evenly.

If you really want to make it easy, put your bearings out in the snow for a few minutes, and if you can get your hub to room temperature, the icy cold bearings will need very little persuasion to go back in. Cheers, Terry.  

[edwardmorris]

No worries mate, I didn't read the disclaimer, but that makes sense, "side-loading" bearings isn't a good thing, even though my bearings came out in perfect condition and I'd have no hesitation re-using them.

The point I was really trying to make is that the removal process you used that you said took you several hours is about the worst I've seen, and if it's in Mark's book, well that's another reason for me not to buy it. With the tool in the link I posted, it's truly a 5 minute job.

There's no trick to replacing the bearings, so don't bother making a special tool, all you need is a similar sized socket to the OD of the bearing so that you can tap the bearing in evenly.

If you really want to make it easy, put your bearings out in the snow for a few minutes, and if you can get your hub to room temperature, the icy cold bearings will need very little persuasion to go back in. Cheers, Terry.

Cool. There are still more to pull when I get to the crankcase, maybe I'll give it a try. Thanks for the temp diff tip as well, I've read about people doing that for driving in bushings and such, makes sense it would simplify bearing installs too. As for the bearing driver, it is supposed to help reduce the side-loading during installs but I suppose there are simpler ways.

I really hope I didn't discredit Hondaman's work here. His book has a LOT more than just this. It helped me because I'm not privy to any special tools and I was planning on replacing them anyway. The similar size OD to tap new ones in is what Hondaman suggests as well for installing new ones. It took ME three hours because I'm so green. I'm sure any seasoned vet would have got them out quicker

[Terry in Australia]

No worries mate, Mark's book is probably mandatory reading for CB750 noobs, but there have been a few errors picked up by some of the more experienced members here, so it doesn't hurt to ask a question if you're still not sure.

I only discovered the special bearing removal "tool" by searching the 'net, or else I would probably have been flogging them out like you had to. I've since bought a puller set that works just like the tool in the link, but with a little more elegance. Once you're hooked on motorcycles, you can never have too many tools..........

[Tews19]

Continue your progress buddy! You have really taken the bull by the horns on this...

[edwardmorris]

This is why Mark was nicknamed the superhero "Hondaman". He called it.

So the internal frame coating from Eastwood showed up today and I was ready to treat the frame today, especially the tubing that was cut and left exposed to the elements. Before I did that, I decided to drill those "Quiet Memo" holes that are missing on my early K2 frame and there it was! A giant puddle of water right as I set the frame down. I did exactly what Mark described, drilled a 7/32" hole a few inches away from where the engine mount pegs are, at the lowest point in the frame. I can't for the life of me imagine how this water got in there? I picked up the frame and shook it, and even more water started pouring out. Did that for about 5 mins and looked like it had stopped. Then lifted it over my head, dodging all the obstacles and making my way to the workbench. I set it down and bam! more dripping. I shook it some more and just decided to leave it overnight so the last of it can drain out and the frame can dry up before I spray on the coating.
After that, I'll make the counterpart holes to these by the gusset plates.

[calj737]

If you can, blow air into the frame from above and force more water out or assist in the drying before treating the frame.

[edwardmorris]

If you can, blow air into the frame from above and force more water out or assist in the drying before treating the frame.

HA, I forgot to mention I did do that for a bit, and also, I set it in front of my propane tank heater in the garage to toast it up. Checked this morning before heading to work, seems to have dried out pretty nicely. Will post later today when I do the eastwood treatment.

[greenjeans]

Keep it going.   Things always take longer the first time at least with a motorcycle restoration.  Welcome to the addiction.

[edwardmorris]

Done with the Eastwood treatment, frame is all ready to go to the weld shop. The extended nozzle isn't the longest one, since its designed for car frames which have several openings and a lot better reach. To ensure coverage, I oversprayed till it was running, I shook the frame with this goo in it to make sure it gets into every nook and cranny. Started with the backbone, followed by the smaller tubing, and finally the down pipes. Don't have the pic but I sent the nozzle down both ends, front and back and sprayed liberally, turned the frame upside down, then let the excess run out.

[edwardmorris]

Here is a before and after. Hopefully this is enough to stop the internal rusting.

[Kickstart]

I'm impressed with your thoroughness.  Nice work!

What is the specific eastwood product you're using?... I might do the same thing with my frame.