Topic: CB750 Lucky

[lucky]

I will show photos of my CB750 build.
First photo is the 1978 Honda CB750 sitting in a storage facility.
At the time I did not even know what year it was.
Fortunately I found out it was a 1978 and had some improved features inside the engine.
It was a beautiful thing and a thing of beauty. LOL

[lucky]

I got it back to my home after taking off some of the unwanted items.
I removed the ugly beat up gas tank, luggage rack, king and queen deluxe split and beat up seat and then we were friends.

When I got it back to my house I did not want to hose it down for fear that water could cause all the dirt,leaves and spiderwebs to clump together. Instead I just started to remove things that looked beyond repair. I mean why waste water-right?

I had hoped to salvage the Kerker 4 into 1 exhaust because they cost over $500. My hopes were gone when I removed it and saw that it was severely rusted and the tubes under the engine were smashed beyond repair. All the flat black spray paint had disguised the truth from me, like a woman you brought home to discover the following morning that was not the beauty you had first thought. Know what I mean? It was too ugly and I could not have it in my workshop, so I made a dump run the next morning and got rid of the mess.
I felt like I had just got home after a date gone wrong.

[lucky]

The next couple of days we(The junker and I) were getting familiar with each other.
Things were ugly but no real big surprises...yet.
Here is a photo part way into the adventure.
With one of the lovely details of the fuse box with missing fuses and stiff as a stick.
Also there was a lot of pieces of rotten old rags and fibers all over the area where a battery would normally be. Of course I expected no battery.
I kept wondering where the main piece of the rag or towel could be.

[lucky]

There was a lot of white powdery corrosion and dirt,pieces of that rag or towel, and leaves .
The entire front of the engine and the bottom were covered with grease.
IT had 29,000 miles on the odometer. I thought it was a lot of grease for 29,000 miles and was wondering why.
Then I remembered as I was taking off the Kerker exhaust that there were no copper gaskets between the exhaust and the cylinder head and maybe that is where all that black was coming from.
IT took about 2 full weeks of cleaning the engine with stick, rags, cleaning agents, and acetone to try to get it to look like a normal engine.
A lot of flat black spray paint to remove also.

[sinister902]

got a good start going....keep up the work!

[lucky]

got a good start going....keep up the work!

Thanks Sinister This is not the most interesting part of the build but show others that it takes some work to produce a good looking bike.

[lucky]

After getting the engine clean of grease and spray paint I found a used cylinder head cover on -bay that was clean so I thought part of my inspection process would include removing the spray painted one and installing the one I bought used.
I did not work out because I found out there is a difference between the 78 model and the others.
The valve covers are different.
So I ended up cleaning and painting the original valve cover anyway.
The black one is the 1978 and the yellow arrows are pointing at the venting area of the cylinder head cover.

Then I removed all of the flat black paint from the valve cover.
I used Eastwood carb paint because it looks like cast aluminum.
The bottom shows the painted valve cover with new screws.

[lucky]

Got all of these parts cleaned and painted.
Some parts are waiting for powder coating/
Saving my money for it.

[mrjack55]

Damn Lucky, you've been busy.

Strong work dude, things are looking pretty good.

[lucky]

Damn Lucky, you've been busy.

Strong work dude, things are looking pretty good.

Thanks Mrjack55! The Dremel tool with small wire brush works very well for the tight spots. Wearing a face shield is a must when a tool is spinning 30,000 rpm.
A little piece of that wire brush could go right through your eye.

[mrjack55]

Thanks Mrjack55! The Dremel tool with small wire brush works very well for the tight spots. Wearing a face shield is a must when a tool is spinning 30,000 rpm.
A little piece of that wire brush could go right through your eye.

I love that little Dremel wire brush!  I've shredded a few myself.  You are right on about needing a face shield.  Those little steel missiles can really do some damage.  I was wearing a sleeveless shirt the last time I used it, and I was plucking steel pieces out of my arms the rest of the day. 

[lucky]

Frame and swing arm stripped so it won't be long before I take them to the powdercoaters.
Ugly job but as a welder I was interested to see the condition of the frame and welds after 33 years of service.
It was stick welded . Good workmanship. The frame had some small 1/32 holes in the tubing for gas to escape while welding, and I thought about welding the holes closed but when they powder coat they bake the parts to 350º or more and I was worried about gasses building up inside the tube sections from paint or oily substances if any, so i decided against that.
I may seal up the holes with silicone or epoxy after powdercoating to keep any moisture out. There was some rust mostly around the lower steering head area probably from all the welding. The frame seem to have a phosphate coating and that probably helped a lot to keep down the corrosion process especially of it got inside the tubes through those small gas escape holes I mentioned.

[Steve_K]

If those holes are in the lower part of frame, I think they are there to drain water.  I believe I would leave them open.  After PC, check that they are open and consider putting some oil in then.
Steve

[lucky]

If those holes are in the lower part of frame, I think they are there to drain water.  I believe I would leave them open.  After PC, check that they are open and consider putting some oil in then.
Steve

The holes are there so that when the tube structure is being welded and hot gases are expanding, if you try to close up that last part of the weld thereby completely sealing the tube, the hot gases will keep blowing the molten metal outward and the weld cannot be completed until the entire weldment has cooled down. In airplanes that hole that is left is filled in with a rivet to seal the tube after it cools down. If the tube is sealed no corrosion can take place because there is no oxygen.
I know because I am a certified welder and a certified welding inspector and I have made aircraft tubular structures.

If condensation gets inside the tube it can drain out that hole, but there would be no moisture in there in the first place if no moisture laden air was allowed in.
Some race cars actually weld in a threaded bung for a  pressure gauge and  couple pounds nitrogen . If a crack occurs in the tubes the air pressure gauge shows a drop in pressure.

[lucky]

Yesterday I was working on the forks and the bottom slider portion needs a new retaining ring and they are not available. So I went to my local bearing supply store and he had a "RotorClip" and it was not 48mm like I needed but he said I could have it just to try. It was 47.6mm
Part no# HO1877 and many bearing supply houses now use the same numbers.
Guess what? It worked perfectly.

Later that day I took my frame to be powdercoated.

[Freaky1]

Nice work! While I do like the little Dremmel wire brushes of all shapes and sizes I perfer media blasting & can't wait to get my little soda blaster together.

[lucky]

I was cleaning and inspecting the foot rests today.
Here is a photo. Getting them ready for paint.

They are a beautiful thing and a thing of beauty.
They have lasted 33 years and are very rugged and repairable.
They can tilt on their axis and are spring loaded to flip back if the bike falls or hits something.
I just had to heat one up to straighten it out.

Maybe the Honda factory considers it a failure because it lasted this long, but you know I would much rather have these than a $250.00-$500.+ gold anodized billet machined fragile thing that will turn to white powder in 10 years.

These steel foot pegs were designed and made when Honda had motorcycle people running the motorcycle dept. Not car people.

[lucky]

This is a finished foot peg cleaned , painted, and grease.

carb silver, with black peg and pin. Mmmmmm

[lucky]

Today I spent time cleaning and painting small parts.
I mostly worked on the Master cylinder to see if I could save it, so I would have to buy all new stuff.

Well it is rebuildable so I ordered a kit for it. I hope it fits.
I have a 1978 but the front caliper was a 1976 because it has the large diameter brake bleeder.
So I thought maybe the Master is a 1976 also.
Ultra sonic ,wire brush, sandpaper, razor blades, the works!

The photo on the lower right is looking down the bore. I sanded the bore with a stick and some #600 black carborundum sandpaper.

If you click on the photos it sows a larger version.

This is the last part to clean and all that is left is the handle bar electrical switches.
Then I can start assembly.

[ekpent]

Doesn't sound like you started up and proved the engine before you started the project. Were you assured that it was a runner beforehand or are you planning a rebuild on it as part of your overall plan.Be a bummer to put all that work in with a crappy broke engine.

[lucky]

I agree. The bike had 27,000 miles supposedly.
There was a lot of grease all over the front of the engine.
Not sure why. When I removed the exhausts there were no copper gaskets.

I cleaned up the engine and checked and replaced the clutch plates and spring ,new alternator case and wiring harness from alternator. New Dynatech solid state ignition.

Removed the oil pan, it looked normal.
Looked under the valve cover-cams ok.
Cam chain adjuster normal.
Cam chain rollers looked ok when I looked in through the oil pan.

Compression check ok but did not want to turn it over much until it has new oil.
But it went over 130lbs. Probably when it has oil and has run a bit it should be 150-155lbs.

valve guide seals?
Probably old, but still in place.

Doing a top engine overhaul could cost $500. or more.
Thinking about that.
It is hard to want to tear apart a engine that only has 27,000 miles on it.

[lucky]

Here is a illustration of where I think this bike is headed as far as looks.

[lucky]

I started replacing the valve guide seals today. I used a suggestion by a forum member to put a piece of string down the combustion chamber when the cylinder that I was working on is at TDC.  I liked that better than compressed air. Quieter too.
I used a piece of 1/4 inch nylon braid rope. It can obtained from a mountain climbing store or a sailboat products store. I had a piece about a foot long and it was more than enough. I used needle nose pliers to push the rope down into the cylinder until the valve stayed all the way up.

To get the keepers out, I just put the rocker arm shaft in position and used a  home made tool and magnet. You have to be VERY careful not to push down hard. It does not take much force. If you put a small rag or small piece of leather under the tool
it helps to keep the tool from slipping and scratching the surface. Make sure the tool is smooth on the edges.

The valve guide seal was hard and brittle. I do not know if it was leaking or not, but I replaced them anyway.

The bottom photo is a little better tool that I cobbled together. Works perfect.

[lucky]

I am replacing the valve guide seals just in case on this engine because I do not know its  history.

I am putting together an engine stand today and tomorrow it will be ready to put the engine on the stand. I will post photos tomorrow.
This way I can run the engine and fully test it for leaks and compression before putting it in the frame.

  If it needs new rings it it is better to find out now instead of having to take the engine out again.

Below is the engine stand.
I just bought a HF stand and used the parts thats came with it to make the engine mount plate.
Click on photo to see a larger photo.   

[lucky]

I am having a very hard time to get the valve spring on and ke the keepers in place.

I made a special tool and it worked very well to get the spring compressed and get the keepers out, but putting them back in seems impossible.
Never had this much trouble.