Topic: Project 2501 Mk. II - 1977 CB750F2

[Floshenbarnical]

Plastic swingarm bushings??? And no, the bushings dont fit quite right and need to be honed. How should I hone them?

Finally got the frame tail shortened and welded and made pretty yesterday. Will give the correct clearance for the rear tire

[Honda Hansel]

Hi
Swing arm bushings
You need to use a Micrometer to check the shaft

My shaft was deformed on both ends from being torqued in the frame
The shaft ends was ever so slightly deformed and would not fit the shaft
Cleaned them in the Lath and the result turned out just great
It only takes 0.001" of a inch to make it not fit proper

[Floshenbarnical]

Time to find someone with a lathe

[BenelliSEI]

Or take the bushing and shaft to a machine shop.

[Floshenbarnical]

I'll make some calls today.

Yesterday I took my frame back to my friend's shop and he welded the tray I fabricated to the underside of the frame rails. Now I have a relatively dry electrical compartment and enough space for a small tool bag!

[Floshenbarnical]

One of these days I'll figure out how to upload pictures to this forum. Until then, we have the power of imagination.

So I'm balls deep into stripping the frame. Fun fact: if you walk into Walmart and ask where the strippers are at, you'll get some funny looks. Aircraft Stripper is THE BOMB for paint stripping. It does in 20 mins what other strippers do in 24 hours. I exercised extreme caution and fully suited up for application/ removal with wire wheel on drill.

Goodness gracious, I wish I'd just taken it to the sandblaster in town. But NO, I had to "save money" and do it the hard way. Even with all the brushes and gallons of aircraft stripper there are so many damned nooks and crannies on the frame that it's just slow progress.

The Comstars, on the other hand, are most definitely getting blasted. There's no way I'll reach the backs of those stars without blast media.

[newday777]

If you are talking about posting pictures from your smartphone with too big of file, open up your photos, screenshot the pictures you want to post, then crop the excess screenshot to what you want to show.
The screenshot reduces the picture size and should fit the parameters of the forum.

[willbird]

If you are talking about posting pictures from your smartphone with too big of file, open up your photos, screenshot the pictures you want to post, then crop the excess screenshot to what you want to show.
The screenshot reduces the picture size and should fit the parameters of the forum.

Kinda clunky but you can just email the picture to yourself as an attachment and often the email ap will offer to reduce the image size for you. personally I just use imgur and crop for content then scale 800 wide for forums. It has been some time since I did that work on the imgur page though.

[Floshenbarnical]

Thanks for the advice everyone. I'm on it. I have a new phone that takes nice pictures so hopefully i can make it work.

I went ahead and just ordered a replacement OEM swingarm off eBay. Like the one I have, it also needs stripping and refinishing BUT it still has the brackets for the chain guard, which is good because my welder friend is away for a few weeks and I want to make progress. This also gives me a little longer to get my bushings honed (why does that sound dirty?).

Chain guard is on the way. I got it for $10 on eBay and needs some TLC. I plan on chopping it down a bit to make it less bulky while still fulfilling its function.

[Floshenbarnical]

Got wheels back from the blasters and got them painted. Looking really good. Semi-gloss Duplicolor black. Looking forward to getting the bearings in and having a rolling chassis!

[Floshenbarnical]

Engine is upside-down. Hondaman was right - the neutral switch was buggered and has been replaced, with a new o-ring. I examined the bottom case seam with a flaslight and a q-tip. It's bone-dry with no signs of tool marks. So I'm going to leave it closed for now. I did notice a small burr on the bottom of the stator gasket mating surface on the engine itself. So I'm going to very carefully homogenize the surface. 2 questions:

1. Who makes the best engine-case gaskets? I'm not splitting the cases. I have used paper gaskets from vintagecb750 before an"d they seem "fine"

2. What is the thread + pitch for the case bolts e.g. stator cover? I need to helicoil two holes, one for the transmission cover and one for the clutch cover.

[willbird]

Engine is upside-down. Hondaman was right - the neutral switch was buggered and has been replaced, with a new o-ring. I examined the bottom case seam with a flaslight and a q-tip. It's bone-dry with no signs of tool marks. So I'm going to leave it closed for now. I did notice a small burr on the bottom of the stator gasket mating surface on the engine itself. So I'm going to very carefully homogenize the surface. 2 questions:

1. Who makes the best engine-case gaskets? I'm not splitting the cases. I have used paper gaskets from vintagecb750 before an"d they seem "fine"

2. What is the thread + pitch for the case bolts e.g. stator cover? I need to helicoil two holes, one for the transmission cover and one for the clutch cover.

Most of those bolts I have bought to replace stock with allen bolts are M6x1.0

Bill

[Floshenbarnical]

Well, life has obviously gotten in the way of some stuff. FINALLY got all the paint off the engine, really masked it up rather handsomely, and put 3 good coats of paint on the underside.

Then I'll flip it and paint the topside after 7 days. That's the waiting period right, to prevent alligatoring with the Duplicolor?

Then it'll go back in the frame and we'll be a step closer to victory! All the covers are polishing up very nicely!

[BenelliSEI]

I do the back end before I put it pack in the stand for “top and bottom” in one shot. I do a couple of fairly light coats, just enough to get good coverage. I usually wait 4-5 days and that seems to be long enough. Definitely wait, or you may get that dreaded reaction!

[Floshenbarnical]

I do the back end before I put it pack in the stand for “top and bottom” in one shot. I do a couple of fairly light coats, just enough to get good coverage. I usually wait 4-5 days and that seems to be long enough. Definitely wait, or you may get that dreaded reaction!

You mean you do a couple of light coats and then wait 4-5 days to put on the final coat?

Thanks for the help brother. Post divorce I’m doing all this in my dining room, which my gf can’t say #$%* about because it’s not her place I’d rather macguyver it in my dining room than be married to my ex and have my old garage, that’s for sure. It does however mean I have to be careful about scratching floors etc.

I was going to black out the entire motor but I was so impressed by your restoration in the other thread that I’ve gone aluminum silver on the body of the engine and am currently using the Caswell 3-stage to get a mirror finish on my side covers so far the stator and clutch covers look like glass, the points cover is a cheap and #$%* steel one, as is the clutch mechanism cover. So for now I’ll tidy those up and have them be silver, and will get some nice Yamiya ones to polish when I have a bit more cash.

It’s been worth the effort! It’s looking wonderful, night and day difference. I’ll sure be proud riding round with this in the frame

[BenelliSEI]

Because the back face of the engine is hard to paint, I usually do it first. Two or three fairly light coats, a few minutes apart. If I have a helper around, bolt it to the stand quickly and do the rest the same way. The stand really helps, so I can start with the engine upside down, then swing it upright for the final coats.

I try and do this outside, in good weather. If I decide it needs better coverage, or find an area I’ve missed, then I wait 5-7 days to make sure the fresh paint doesn’t “melt” the earlier coats.

[Floshenbarnical]

Absolutely. I wiped it down w acetone and painted the underside last Tuesday. I flipped it and wiped it down again today and will start painting when I’ve had my breakfast.

Somewhat annoyingly I scraped off a tiny sliver of paint on the underside near the neutral switch but I’ll wait until the motor is back in the frame and just spot paint it. I’m sure once the engine has had a few heat cycles the paint will adhere better.

Now I just need to take the chrome off of this transmission cover so I can polish it up, and we’re in business!!

[Floshenbarnical]

Alrighty. Replaced the transmission cover w a cheap eBay aluminum-only one and polished it up. Put all covers on w new gaskets and noted the two case holes that need rethreading. One is bottom left on tranny, one is bottom left on stator. I’ll take care of that when I have a rolling chassis - I need this thing to start coming together. It wasn’t leaking from the stator or transmission mating surfaces so it can live until it fires up in my opinion.

Got a burly female friend and her skinny boyfriend to help me tip it (carefully) on its side, pop the frame on, slide the bolts through, and turn it upright. Got the front bracket on, the rear bracket still needs to go in the oven.

Then we carried the thing out of my house and down a three-storey wooden staircase slick with algae and put it in my car. Then we moved it over to my gf’s garage.

Here it is! Looking a bit dirty because our hands were dirty. But I got it in the frame with no scratches or dings.

I was originally going to paint it black but then I saw benelli’s project and decided to give him a run for his money.

[BenelliSEI]

Kudos to you. I’m never organized enough to have the engine ready for a bare frame…. Smart!

[Floshenbarnical]

Just worked out that way tbh - I wanted to strip the frame to treat and paint it, so everything had to come off. Then I just moved onto the engine.

Current status: putting the wheels on today when I get them back from the tire place.

[Floshenbarnical]

Not getting the wheels back today because they’re closed.

Reassembled shiny new caliper assemblies. Piece of cake.

However, my manual is missing the pages for rear wheel bearing etc reassembly. There’s an exploded view of the front wheel, which is very helpful, but the rear Comstar pages are missing.

Does anyone have a copy online I can peek at? Regular non-inverted Comstars.

[majorzozo]

Looks great.  Partzilla has an exploded view.  Link below.  No directions just a picture.

https://www.partzilla.com/catalog/honda/motorcycle/1977/cb750f-a-750-super-sport/rear-wheel-disc

[Floshenbarnical]

Looks great.  Partzilla has an exploded view.  Link below.  No directions just a picture.

https://www.partzilla.com/catalog/honda/motorcycle/1977/cb750f-a-750-super-sport/rear-wheel-disc

Thanks, that was extremely helpful. Getting the long pivot tube lined up was a pain but it went in. Froze the bearings overnight and hammered them in carefully. Still a pain though.

Rear tires needs washing. Had to top off the black paint with a paintbrush around the cooling fins, will wait to sand again until it’s properly hardened.

[SOHC4 Cafe Racer Fan]

I'm in for this. It's looking clean (minus the tires).

[Floshenbarnical]

I'm in for this. It's looking clean (minus the tires).

Washed now.

Fiberglassed the seat pan. Tomorrow I’ll shape the cowl out of foam.