My Nighthawk: 750SC

[mk3brent]

Anyone know where I can find replacements for these?

They're the rubber booties that go to the sliders.

Don't know if I could go w/o them, but would like to have them nice and new.

[mk3brent]

Cleaned up the rear brake, and am getting ready to paint.

Going to finish cleaning up the calipers, and install the pistons and seals.
(Forget about my last question about those rubber sleeves, turns out there's a set in the rebuild kit I bought months ago.)

[shinyribs]

You take the best pictures! At first I thought you were stealing images from a sale site,then I realized that you just take really good pictures!lol


You're making good progress man!

Oh,can't help ya on the rubbers. Sorry,but no clue there. Good luck!

[mk3brent]

Haha, thanks.

Photography is a hobby of mine.
More photos to come once the bike is put together.
I'm trying to document the whole thing the best I can.


Last night I spent a good hour trying to find the correct caliper brackets for this bike.
I have the left side, but the right side was missing.

I found something that looks like it matches, so I bought one.

I don't know how many dual pot calipers brackets Honda made, but I'm sure it's "a lot" and "complicated."

I'm working on the rear wheel, but I think I'll throw the rear suspension and swingarm back on to get the bike rolling out of the garage to get some sun.

[mk3brent]

Got a couple more things accomplished.

I thought I had some new pistons for the calipers, but sadly do not.
I cleaned the old ones to the best of my ability, however they have been sitting for so long, I'm afraid they might have an issue with the pitting.

I will still install them, and test them to find out.

[shinyribs]

I may have some pistons for those calipers. I'll dig them out and get some measurements.

[mk3brent]

Everyone likes pictures, ja?

Got a couple more things done when I got home from work today.

Popped out all the shims to measure them.
I'll calculate the correct clearance shims later though.

I started work on the seat.

Since the 900F tank wasn't meant for this frame, I had to do some modifications.

I chopped the center section of the 750SC frame, and left some of the pipe there to bridge to later.

I plan on bolting down the tank, then making the seat padding flow into the lines of the bike.

Anyway, here are some shots.

I also got a nice photo of the swingarm after I painted it.
I'll probably buff it to shine even more.











My trusty porti-band:










Look at them liiiiines.

[mk3brent]

Cleaned up 4-into-1.

[TOOLS1]

mk3brent wrote

Cleaned up 4-into-1.

Is your OCD under control? You have the worst case I have ever seen.
TOOLS

[mk3brent]

My OCD knows no bounds!


Here's proof:

Cleaned up the rear suspension, and re-coated the exhaust clamps.

[mk3brent]

FedEx dropped off the front tire this morning.
Waiting on the rear now.

[mk3brent]

Did my valve clearance calculations.

Is there anything wrong with going to the tighter end of the tolerance?
I am intending on starting tight, as the parts wear I'll have more room to go.

I know that with heat, shooting for .060mm may force me out of tolerance once hot... So maybe shooting for that is a bad idea.

Anyway, I did make the spreadsheet, so I can easily modify my target to get my new shim sizes quickly.

What do you think?

[mk3brent]

Just a couple more pictures:





Time to clean up the garage, it's getting messy.

[mk3brent]

I needed shims, so I decided to cannibalize the locked up 750 I had to pull out of the bike in the beginning.

After getting the cams out, and the shims, I thought I might just take the head off to see what's wrong in there.


I guess the previous owner put rust in there.
Did a really good job too, cause this thing is sstttuuuck.

[seestheday]

I don't know about nighthawks but the dohc cb 750s need to be with 0.004 and 0.006 INCHES. 0.06 mm is too tight for our bikes. Nighthawks might be different, I just don't know.

[mk3brent]

If I use the chart, and compare it to my calculations the real clearances using nominal shims is pretty spot on.
.06 - .13mm

Check out this spreadsheet.
I added a section for nominal sized shims and their result clearance. Should be pretty good here, around .08 to .10mm



I'll repost this, but it says .06mm to .13mm.

[mk3brent]

Anyone have a picture of this bracket on their dual pot calipers?

I got the correct mounting bracket, and need to order the special pin bolts when I saw this guy.

I don't know yet where it's supposed to go.
I'll have to find it in the FSM maybe.

[mk3brent]

Putting new seals back in the calipers.

Also the pistons.

[shinyribs]

I reeeeally like that seat! And seeing your motor made me cringe! Was that water standing in it or some sort of pentrant you are using?

Looks like you didn't need caliper pistons after all...so I don't feel so bad about flaking out and totally forgetting to look for you.

[mk3brent]

No worries, friend.
I knew they were the right size, I was concerned with the pitting on them.
I think they'll be fine, but I'm an engineer by profession so I'm one of those overly cautious folks.


I mic'd out the valve shims I got from the seized 750, but didn't find a 3.15mm. Going to have to order some on fleabay.

As for the standing water, that's actually diesel and marvel mystery oil.
Had I known what was really inside the cylinders, perhaps I would have saved 5 ga of the mixture for something more exciting.