Topic: Alan's CB750 K8

[Alan F.]

Today I gave the cylinder studs and the exhaust studs a shot of PB Blaster, and left them to sit. Then I tore down that set of spare forks. Had to drill out the damper rod bolts at the bottom since they just wanted to spin with a wrench on them. I got them apart though. Unfortunately they're not in better shape than the set that came with the bike so I'll be using those with the new lower triple since the lower bearing race had already been removed. I'll get those together tomorrow.

[Alan F.]

I didn't get the forks together, 5 hours of driving everyone to places they needed to go ate up all of my energy.
I did however manage to order up Hondaman's 750 book, that should drop the number of my questions way down.

[Alan F.]

I just called up to ask about my Partzilla order. 2 items were on hold, available on the 22nd, 5 DAYS AGO. That was 5 DAYS AGO and no email, no communication of any kind, and they already took my money, what gives I ordered these on the 18th, 9 DAYS AGO!

For comparison my order from 4into1 placed on the 18th and shipped on the 20th is scheduled to arrive tomorrow. My order from Randakks (billed as Dime City Revival) placed on the 18th arrived on the 23rd.

After just six minutes on hold Partzilla told me that I was #140 in their call queue, so I chose the option to have them call me back. Seriously? I'm getting pretty bent out of shape, likely I shouldn't be considering the state things are in,  but I have an engine to build here so I'm chomping at the bit i guess.

Don't order from Partzilla if you're in a hurry i guess is the take away here. The Dime City group which includes Z1, Dime City, Mike's XS and probably a few others was just fast.
4into1 was fast too, the delay there is UPS which I can cope with much easier because UPS has always been crap. I quote Deadpool's comentary on wearing the Brown Pants.

[Alan F.]

My 4into1 order arrived this afternoon. 

Around 4pm Partzilla called and offered to upgrade my order with Expedited Shipping! But they don't expect my order to ship for ANOTHER SIX DAYS, June 1.

Uhhhhhggg!     

[seanbarney41]

Really, the only #$%*ty thing about Partzilla is they don't tell you what is going on.  When they list an oem honda (or worse yet, Suzuki!) part as available, all that means is some Honda parts dealer somewhere has it, even if they are really getting it from CMS in the Netherlands or Bob's Cycle Supply in Bum#$%* Wyoming that has not even shown up for work in 2 weeks let alone answered the telephone if it works.  So when you order oem from them, it often has to get shipped to them and then shipped out to you.  For whatever reason, most other online oem dealers either tell you the full situation, or have it drop shipped directly to you.  If you don't like this situation, try getting oem parts for any other brand of 50 year old bike.  You mostly just won't.  Now during coronavirus, the whole thing is, of course, magnified.  Up until very recently, basically nothing was leaving Japan, period.

[Alan F.]

Yup, I hear ya loud and clear. I guess I'll start replating hardware and lacing wheels...

[Alan F.]

I've been cleaning up nuts and bolts with an acetone soak for a few days followed by a few days soaking in 5% white vinegar.
I don't have any pictures of those steps, sorry it's a dirty process. I'll get some before and after pics at the polishing step.

For cleaning parts I soak parts in regular acetone bought by the gallon can and for de-rusting I soak parts in regular 5% white vinegar from the grocery store. To keep these from evaporating in the basement with the dehumidifier running I use shallow plastic containers from Dollar Tree (not sure if they're a national chain or not) I can't seem to find the ones I use on their website but they're over a foot long, about a foot wide, 3" deep, made of translucent plastic and they have lids that snap on. Like the name brand Gladware. Anyway these are dirt cheap and are resistant to acetone, I left parts soaking for 2 days.

Then I ran my accumulated nuts and bolts through my DIY Zinc plating process. Lots of people do this differently and there seems to be no real "right way" unless you're a professional I suppose.
I finished up at about 9:30 last night and gave everything another acetone rinse before laying the parts out to dry on clean paper towels overnight. At about 5 this afternoon I tossed half of it into my vibratory polisher with corn cob pet bedding, I'll check on it at the 2 hour mark in about 15 minutes and take some photos.

On another note, since I'll be adding exhaust spigots so I can run the Kerker pipe from my K3, I was able to successfully remove all 8 exhaust studs from the cylinder head without breaking any. A few days ago I gave them all a shot of PB Blaster and that did the trick. One thing I recommend is that you scratch around each stud with a pick before spraying the studs, my head had been painted by the PO and a couple of the stud threads seemed to my eye to be sealed by the paint.

Brb, gonna check the polisher. Hold my beer.

[Alan F.]

Ok, 2 hours in the polisher won't be enough.

This is what parts were looking like after plating:



And after 2 hours in the polisher with corn cob:


While scooping out the contents of the polisher I found a stud and nut from another project, this is the finish I'm waiting for on this batch of parts:



For comparison here are the dirty, rusty exhaust studs that I removed earlier today:

[Alan F.]

Today I took the tarp off the engine and started removing studs with the double nut method. The first and seventh ones were just stuck and wouldn't budge.

I really don't want to break anything so I added some heat and some more heat, not to the stud only the case, enough to get some oil smoke out of the cases but it still wouldn't budge with the double nut. Ok one more shot of PBB then it was time for double visegrips down low, Bingo! Both studs out easier than I would have imagined.


Next I wanted to clean some of the crap out of the threads, I remembered reading that you can make a thread chaser by cutting a slot at the end of a stock stud then bending it 90 degrees in a bench vise, so that's what I did.

I thought it worked pretty well.



I cleaned the thread chaser slot and each stud hole with a compressed air can, it was just enough. I also took off the kickstart lever and wrapped the cases back up in the tarp and bunjied it tight. I won't open that back up until my new primary chain tensioner eventually arrives from Partzilla....

I've got nuts and bolts in the polisher to check on, more updates to come.

[Stev-o]

Nice thread cleaning trick!

[Alan F.]

Thanks Steve.

Some pics of my first batch of parts out of the vibratory polisher, not perfect, not new, but they're clean and won't rust easily or quickly.







Bigger items I just touched with Scotchbrite:


I even plated the exhaust collars:

[Alan F.]

When I bought the HF vibratory polisher I used the 15% off coupon and used the savings to buy a timer to plug it in to.
This way I can not only time my polishing runs for consistency, but I can keep from pissing off my neighbors by running the thing well inside regular hours. This afternoon I took a look and called that run complete.



Then I set up my grinder with a wire wheel that I'd picked up at a flea market a few years back for $2, it took the clearcoat right off of my fork lowers and I started polishing with black emery:

I'll give them each some more time tomorrow to polish out some more pits, but I probably won't move to a finer polish on these.

[Alan F.]

I spent some more time on the fork lowers today. In the previous photo you can see the orange peel texture, I wet sanded most of that off with 400 grit:

And then set up the polisher with black emery:

Then another touch of the polisher with brown tripoli on another wheel:

[Alan F.]

Better photos

[Alan F.]

I'm back to work this week so it's been a slow one for progress here. This afternoon I painted the lower triple with black Appliance Epoxy, and the upper triple, handlebar clamps, bolts and top steering nut with what was labeled Flat Black Enamel but it looked plenty glossy to me while wet.
I'll get some photos in the morning and we can figure it out then.

[Alan F.]

Since I got called back to work I haven't had much time for this project so today I'm making some progress.

I want this thing to roll so I'll be bolting on the old rusty wheels/tires until I get the other set of wheels ready.


The top triple I painted last night dried flat after all, not perfect but I'll run with it. The lower triple I sprayed with glossy Appliance Epoxy, it came out ok too.

I'm still trying to figure out what resolution photos I can link to and which I need to upload so they don't look stupid, I think I've got it now.

[Alan F.]

Ok, steering bearings. I cheaped out and bought Rising Sun tapered roller Steering bearings, it's a complete kit with seals and all so why not?
I knocked out the old races from the frame neck:

My notes from calculating which spacer to use on the steering stem:
'Frame neck inside measures 6-3/8" between the steps that the bearing seats will seat against.
New top bearing and race are 9/16" high
New bottom bearing and race 9/16" high
Old bottom bearing with both races and balls
Measures 3/4" high
Stem is 7" from the very bottom to the bottom of the first step smaller where the top bearing fits on.
3/4" - 9/16" = 3/16"
A 3/16" spacer will be needed beneath new bottom bearing 3/16" = .187" = 4.75mm
The Rising Sun kit includes a 3/16" spacer, I placed it on the steering stem, inner diameter fits good. I followed it with the lower seal (which adds only about .030") greased the seal, packed the bearing, and drove the bearing into place (all at room temperature) with a correct inner diameter aluminum bushing I made on my lathe and a length of square tube steel stock. I drove until I could no longer turn the 3/16" spacer, then gave it a few more wacks.'


Then I tapped the lower race into the bottom of the frame neck as far as I could get it using a hammer and brass drift, put the top race in as far as it goes with a hammer and block of wood, when fully seated the top race sticks out a few mm from the neck.
Then I placed the upper bearing on the steering stem, threaded on the nut and turned the lower triple lock to lock to help set that lower race, it goes pretty deep. Eventually I was limited in travel by the steering stops... a fine progress report, then a little while longer and the bottom race was set. Then I popped on the top triple and its nut. No grease in the upper bearing for now, and no seal, this will all come off when the frame goes on its side to slip it over the engine.

[Alan F.]

Forks are reassembled, and back on the bike, rusty front wheel makes it a roller!
It's been a long time, I think I've got the forks on the wrong sides... 

[seanbarney41]

Yeah you do

[Alan F.]

Oh well, I guess I'll leave it this way until it's time to lay the frame over the engine.

[Alan F.]

I brought out an old tank that I'd picked up from another member years ago, it's full of varnish and rust, has some light dents and chips but seems solid enough otherwise.


I also bolted on the rusty rear fender and perched a CB400T seat on top, it doesn't fit, I could probably adapt it, but I'm not inclined to.



What does one do for a seat when using an early K tank on a late K frame? Just use a stock seat and move the hinges and latch backward to close the gap between the seat and tank?

I suppose I could use an early seat pan if I would be relocating hinges and latch anyway. The thing that I'm curious about is what to do about the extra bit of rear fender that new becomes exposed. There will probably be a larger gap between grab bar and seat I suppose.

[Desert-SOHC]

No help on the seat, I used all K8 stuff on mine, but someone will know.  It's comin right along though.

[Alan F.]

Thanks, I'd like to get more done today but we're catching up on stuff around the house so far. Maybe I'll get my K3 wheels out later and start on those bearing retainers.

[Alan F.]

Haven't had much chance to get back to this bike between the heat and work. I woke up to an email that partzilla is finally shipping me the second of the two cam chain roller pin rubbers, it should arrive this week. I guess I better make sure everything is ready to go back together.

[Alan F.]

Had some free time this afternoon so I flipped over the K8 engine to have a look at the oil pump screen and primary chain tensioner. One look at the oil pan and another piece of the PO puzzle fell into place. The oil pan had been black powdercoated, poorly, just like the valve cover, oil filter housing and primary sprocket cover. The kid I bought it from said he had tried his hand at DIY powdercoating... so I guess he's the one who went wild with the blue silicone on all of the gaskets...as evidenced by the powdercoated oil pan and blue silicone on both sides of the gasket.

I cleaned all that off, smoothed some burrs and reassembled dry with an OEM gasket. Torqued the 6mm bolts to 8 ft/lbs, replaced the drain plug crush washer and torqued it to 25 ft/lbs.

Oil pump screen had some crap on it, crunchy and brown like maybe it was old sealer of some kind, gone now. Primary tensioner was surprisingly soft and supple, likely not the Factory unit and I'm happy with that.