Author Topic: My 1975 cb 750 Build (Read 17302 times)

PPG9944 · « **Reply #50 on:** February 06, 2015, 08:57:59 PM »

My buddy let me play with his engraver. This valve cover was already messed up so i wound up sanding the chrome off the top and then did that with a stencil.

PPG9944 · « **Reply #51 on:** February 08, 2015, 08:09:26 PM »

So I got that Breadbox soaking in some Evaporust to clean it up. I'll let it soak for another day and scrub it all good. I put it up to my carbs just to see fit and it seems like the Outer Carbs will line up but one of the inner carbs will be a little off. Can I get some rubber hose or something to make adapters or something.

Also i was thinking i should probably use the stock airbox boots which are a little smaller in diameter than the hole in the plate.

Any input on all this stuff would be excellent because I'm still a bit unsure of how it's all supposed to work.

Also for reference, the boot on the left is what is in the breadbox, the right is the stock CB750 air boot. Could anyone identify what the left one is off of?

PPG9944 · « **Reply #52 on:** February 15, 2015, 11:48:39 AM »

This thing cleaned up pretty good. I'm still doing research on how to make this thing work because the inner 2 holes are offset a hair to the carbs. Im thinking about getting the stock rubber stack intakes in there and then connecting them to the carbs with a radiator hose. Also tossing around the idea of using the stock airbox mounts to hook up up to the top of the box. The chrome is in pretty poor shape but it will get painted so I dont really care too much.

PPG9944 · « **Reply #53 on:** February 18, 2015, 05:37:38 PM »

Did a little cooking with some wintergreen oil. I put all the rubber boots in my pot with some water. Let that warm up then added the wintergreen oil. I only had 1 ounce but I'm hoping that will at least get the boots somewhat pliable.

This stuff starts out smelling not so bad and then turns into a pretty rough smell haha oh well.

PPG9944 · « **Reply #54 on:** March 07, 2015, 04:50:34 PM »

The weather in illinois finally warmed up enough to do things. I rebuilt the oil pump, checked the stator but I'm a bit unsure about it, I got a reading of .8 ohms between the 3 wires. Is that acceptable?

Looks pretty clean under there.

Getting that screen off was a pain but I got the oil pump split, replaced the gasket checked out the internals and replaced some o-rings.

And mounted back up.

Tested the stator and field coil. The field coil had a reading of 7.3 ohms which is cool but the Stator had readings of .8 between the 3 wires. Again, is that a problem? What is acceptable?

I also got the clutch lever and switches mounted from a 2003 honda cbr954rr. The controls will look cool. The speedometer is just a rough idea of what i want to do. Thinking about getting one of the acewell units.

PPG9944 · « **Reply #55 on:** March 10, 2015, 05:01:42 AM »

I'm definitely learning how to weld. The welds look like #$%* but I'll grind the excess off and clean up the spots that i missed. This thing will definitely look mean once I am done with it. I've got a few more ideas on what i want to do to this thing.

Vinhead1957 · « **Reply #56 on:** March 10, 2015, 06:12:32 AM »

A round surface is very difficult to stick weld. Have you tried gas welding? It takes time to master but it can be fun learning. Many welding suppliers have free learn to guides on their websites.

PPG9944 · « **Reply #57 on:** March 10, 2015, 04:32:03 PM »

This is my first experience welding and it's definitely not easy but i think ill be able to clean this up and make it structurally sound and look decent. I do want to learn how to weld well though.

PPG9944 · « **Reply #58 on:** March 10, 2015, 07:00:26 PM »

This thing is finally starting to take some shape. I think I have to raise the suspension and mount it in the stock position. It's got those lowering blocks installed right now.

Riceman · « **Reply #59 on:** March 15, 2015, 07:40:58 PM »

If you are using an Arc welder,try dragging the rod at a 45º angle till it starts then
straight up for the weld.
every time you stop welding ,tap the tip of the rod on the ground or something hard to break off the flux.
The flux will rap around the filler rod and won't make contact with the metal to start arcing/

PPG9944 · « **Reply #60 on:** March 15, 2015, 07:51:36 PM »

Ah thanks for that. That makes sense. I probably shouldn't have learned how to weld on a tube but i think it'll work. The structural integrity of the hoop should be ok. It's never going to be load bearing really so I think the way i did it will work. Definitely need a lot more practice welding.

Riceman · « **Reply #61 on:** March 15, 2015, 08:09:32 PM »

Also if you have an AC machine,buy the ac rod,makes a big difference.

PPG9944 · « **Reply #62 on:** March 22, 2015, 03:10:12 PM »

Went to Ace to pick up a door hinge. Hacked it all up but I wanted to have a locking seat on hinges.

And I got the fender mounted up for now. Still needs 2 more mounting points to make it real solid but I'm also not sure if I'm feeling it at all so we'll see. Next up will be trying to relocate the electronics tray and to mount the ignition switch.

That dent in the oil tank looks a lot worse in the pictures than it does in pictures too haha

evanphi · « **Reply #63 on:** March 24, 2015, 08:09:10 AM »

I have the Acewell speedo/tach combo unit. It is fantastic.

If you do the magnet mounting point as suggested earlier (which would be very cool!), the starting input diameter is easy, just the usual wheel diameter... but then you need to reduce it by the same ratio of your rear sprocket to front sprocket.

PPG9944 · « **Reply #64 on:** March 24, 2015, 04:51:59 PM »

Quote from: evanphi on March 24, 2015, 08:09:10 AM

I have the Acewell speedo/tach combo unit. It is fantastic.

If you do the magnet mounting point as suggested earlier (which would be very cool!), the starting input diameter is easy, just the usual wheel diameter... but then you need to reduce it by the same ratio of your rear sprocket to front sprocket.

I'm glad that makes it sound like it's a solid investment. I know exactly what I need but I don't to drop all that money all at once. Im trying to space it out a bit.

PPG9944 · « **Reply #65 on:** March 29, 2015, 04:32:24 PM »

Had to get some work done on my Shadow that's actually in riding condition but productive weekend nonetheless.

Some of you have fancy tools, I wind up making what I need.

Metal Brake! Surprised at how well this wound up working.

This is kinda the idea here, I need to find some bolts that can mount flush with the hinge plate and make some sort of plate to mount to the plunger

And I'm tossing this idea around, got this tank bra that's just hanging around. I'm thinking this will be my left side cover and I plan on mounting the ignition switch underneath it in the bottom of the triangle.

PPG9944 · « **Reply #66 on:** March 31, 2015, 07:50:41 PM »

Got some stuff done tonight. Made a little bracket to hook up the seat plunger to the seat pan. Got to practice a little welding. I still suck. Oh well whatever little bracket isn't structural

And this is kinda what I'm thinking as far as placement of the ignition switch. Gotta get it off that big bracket obviously and make it fit somehow but I think it'll work.

PPG9944 · « **Reply #67 on:** April 12, 2015, 05:31:11 PM »

Couple updates.

Helped my buddy work on his bike and he hooked me up with some take offs. The chain is pretty much brand new should be solid.

The original hinges didn't work how I wanted to so I picked up some plain steel door hinge and got it all welded and fitted up. It fits much better now.

Today I got the gap in the rear closed up and I like where the seat is now. There is still a gap where the bend is but I'm thinking I might use that to my advantage and figure out some sort of turn signal hookup there.

It's finally starting to look like a bike again. I need to order some new spokes. The wheels will get taken to get the powdercoat treatment.

I was looking at the the spokes on 4into1.com. They're about 50 ish bucks a set. Seems like a good deal. Has anyone used these? The buchanans are nice but I don't have the budget to drop 125 bucks a set.

PPG9944 · « **Reply #68 on:** April 19, 2015, 02:39:05 PM »

I didnt like where the original foam idea was going so I met a cool guy that does upholstery. He sold me a piece of foam he had lying around and here we are.

Couple progress pics from today

Rough cuts.

More refined.

PPG9944 · « **Reply #69 on:** April 26, 2015, 04:05:49 PM »

Got some progress pics

I was getting pressure points sitting down just the foam, so this was my solution. The seat feels much better.

I dug around the Magna I have as well and pulled out this Regulator/ Rectifier combo. Gonna make it work

Also, I committed to the idea of a removable seat cowl. Went to the store and picked up some fiberglass resin, and some fiberglass mat. On the way back stopped by the dumpster behind the store and wound up finding all this Insulation foam.

So I got home and glued it all together

Progress 1

Progress 2

I'm going to spend a lot of time shaping this freaking thing to how I want it.

I seem to have this thing where I find stuff to do the hard way. Ha oh well. We'll see how this experiment pans out

calj737 · « **Reply #70 on:** April 26, 2015, 05:40:40 PM »

isn't the Magna a DOHC? If so, you might double-check the wiring connections on that R/R.

PPG9944 · « **Reply #71 on:** April 26, 2015, 05:43:17 PM »

Quote from: calj737 on April 26, 2015, 05:40:40 PM

isn't the Magna a DOHC? If so, you might double-check the wiring connections on that R/R.

Yes, the magna is a v4. Im not well versed in electronics. Why wouldn't this one work?

calj737 · « **Reply #72 on:** April 26, 2015, 05:51:20 PM »

it can, but I believe they are wired differently. Just ran through a thread, and I believe it was "Scottly" who was advising on the differences between DOHC and SOHC R/Rs. I scanned the SOHC Bikes, but couldn't recognize the thread. Perhaps he will venture past and advise?

I think this thread was also mentioned... http://forums.sohc4.net/index.php/topic,141957.msg1609562.html#msg1609562

PPG9944 · « **Reply #73 on:** April 26, 2015, 05:54:15 PM »

Quote from: calj737 on April 26, 2015, 05:51:20 PM

it can, but I believe they are wired differently. Just ran through a thread, and I believe it was "Scottly" who was advising on the differences between DOHC and SOHC R/Rs. I scanned the SOHC Bikes, but couldn't recognize the thread. Perhaps he will venture past and advise?

Hmm. Looks like I'm going to have to do some research on the matter then and see what happens haha.

PPG9944 · « **Reply #74 on:** April 30, 2015, 04:56:25 PM »

Hit the cowl with the sander a bit more. I'm liking it but im gonna have to have the top come lower still. I might take out one or 2 of the layers from the bottom since the fiberglass will come up to the bottom of the seat at the back and it will wrap under the seat where it will be mounted somehow. At least that's how I'm seeing it.

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Author Topic: My 1975 cb 750 Build (Read 17302 times)