Author Topic: My first 750: '76 CB750F (Read 20868 times)

Bankerdanny · « **on:** October 22, 2017, 10:43:00 AM »

I thought I should get a project thread going.

If you didn't see my thread in the SOHC4 board I picked up this 76 CB750F last weekend. Complete and appears to be in good shape, although the tank is suspect.

Bankerdanny · « **Reply #1 on:** October 22, 2017, 10:46:40 AM »

It came with a still dry brand new battery. So last night and put in the acid and turned the key, nothing, no lights nada. Checked the fuses, most were the shorter style. Plenty of corrosion, so I knocked off for the night.

Bankerdanny · « **Reply #2 on:** October 22, 2017, 10:48:21 AM »

Bought correct fuses today, cleaned up the connections, including at the harness and reinstalled. Of course now I can't find the key, so I can't test right this second. Decided I would post some pictures.

Bankerdanny · « **Reply #3 on:** October 22, 2017, 07:19:10 PM »

And here's the reason the PO sealed the tank, then completely filled this indented area with bondo

Bankerdanny · « **Reply #4 on:** October 22, 2017, 07:20:08 PM »

I'll also be buying an ignition switch

seanbarney41 · « **Reply #5 on:** October 22, 2017, 08:00:54 PM »

Damn, that sucks...2 very typical problem areas for F bikes though. I have a half decent 77k tank you can have. I also recommend using a key switch from an earlier or later bike. Goldwing switches can be adapted along with several other early '80's Honda's. Went the other direction on my current f and used early key switch.

DSCN1191 by Sean Barney, on Flickr

Jerry Rxman Griffin aka MuthaF'er · « **Reply #6 on:** October 22, 2017, 10:59:49 PM »

Replace the plastic base. Cheap.

One thing to remember on this switch is it also contains the fork lock.

Bankerdanny · « **Reply #7 on:** October 23, 2017, 04:50:12 AM »

It's the same switch as my 550 so I have experience taking them apart.

seanbarney41 · « **Reply #8 on:** October 23, 2017, 01:20:57 PM »

It's easy to hot wire too....just have to make some jumper wires to plug into the connector

Don R · « **Reply #9 on:** November 02, 2017, 07:59:05 PM »

On one of my F's I peeled off the brittle plastic and coated the exposed key switch terminals with brush on electrical contact sealer. Liquid tape.

Stev-o · « **Reply #10 on:** November 03, 2017, 08:00:59 AM »

Subscribed.

That tank can be saved with Caswell. Put duct tape on the holes before pouring the epoxy in.

Bankerdanny · « **Reply #11 on:** November 06, 2017, 11:40:59 AM »

Thanks Stev-o. I'm going to at least make the holes smaller by brazing, then re-coat. I am going to pick up some welding rod this week and see what I can accomplish next weekend.

Bankerdanny · « **Reply #12 on:** January 16, 2018, 10:44:56 AM »

Finally got around to brazing up the holes in the tank, including some new ones that turned up during the brazing process. I haven't had a chance to leak test, but it doesn't matter since I plan to strip out the liner that is in it and reline the tank.

Bankerdanny · « **Reply #13 on:** January 16, 2018, 10:47:24 AM »

I also discovered another gift from the PO, although I think this was one he probably got from the owner before him

Bankerdanny · « **Reply #14 on:** January 16, 2018, 10:49:04 AM »

Last but not least, the Kerker muffler is basically dead too. Oh the joy of a "cheap" old motorcycle.

Stev-o · « **Reply #15 on:** January 16, 2018, 11:00:02 AM »

The cheapest bikes can be the most expensive bikes! [dont ask how I know]

Jerry Rxman Griffin aka MuthaF'er · « **Reply #16 on:** January 16, 2018, 11:19:00 AM »

Good start Danny. The tank could end up being a lost cause. I just hope it doesn't turn out to be a sieve when you get it cleaned out. Keeping my fingers crossed. Speed Bleeder Co has been know to "fix" buggered calipers too. The good news is the exhaust is easily replaceable. Keep at it, it's just time and $$ LOL.

Bankerdanny · « **Reply #17 on:** January 16, 2018, 11:19:55 AM »

Ran across a guy selling a mostly complete F3 without a title locally (via a Facebook group I joined today). I just PM'd him. The has a Kerker muffler like I have now.

I was thinking about tracking down a set of F2/3 wheels anyway. So if I could get this cheap enough I could swap the whole front end, plus the wheels and brakes and have a spare tank and seat setup.

Don R · « **Reply #18 on:** January 16, 2018, 12:34:28 PM »

There's an f3 lurking near me, it's all rusty, locked up, no title and the guy thinks it's worth $400. I'll throw a $200 offer next time I see him.

I'm a big fan of the F's. I still consider my triple disc 76 the best all around bike I've owned, although the sandcast I got with the help of the F money is pretty sweet. I'm hoarding a pair of F tanks and a 75 rear frame and swingarm from a wreck. Someday I plan to build a cb750 superbike lol.

Bankerdanny · « **Reply #19 on:** January 16, 2018, 12:52:17 PM »

I heard back from the guy by me, he wants $700, no carbs on the bike in the photo and needs a seat cover. I paid $850 for my fully assembled bike with a perfect seat and the title.

seanbarney41 · « **Reply #20 on:** January 16, 2018, 01:11:10 PM »

Danny, keep in mind, that rear caliper costs around $150 on ebay, unless its in the same condition as yours...rear masters just as much, rear mc rebuild kits are $80-$100...but then nobody can sell a nice clean original f for more than about $3500...#$%* does not add up...

Stev-o · « **Reply #21 on:** January 16, 2018, 01:59:24 PM »

Quote from: seanbarney41 on January 16, 2018, 01:11:10 PM

Danny, keep in mind, that rear caliper costs around $150 on ebay, unless its in the same condition as yours...rear masters just as much, rear mc rebuild kits are $80-$100...but then nobody can sell a nice clean original f for more than about $3500...#$%* does not add up...

...and a nice tank $175...

GritCity750 · « **Reply #22 on:** January 19, 2018, 06:05:40 PM »

Quote from: Bankerdanny on January 16, 2018, 10:47:24 AM

I also discovered another gift from the PO, although I think this was one he probably got from the owner before him

Wow, I would have gone with a metric screw thread on that. Sheesh!

Bankerdanny · « **Reply #23 on:** March 18, 2018, 10:11:55 AM »

Finally spent a quality afternoon working on the F. Added a couple more brazing repairs to the tank to holes that revealed themselves after I started removing the liner.

Figured out part of why I had no power to the ignition switch. One of the DPO's (probably the inexperienced one I bought the bike from) had moved the wire that takes power from the starter solenoid from the battery side to the starter side.

I also determined that my ignition switch needs replacing. When I took the switch apart I discovered that the contact for the main power in was recessed down into the plastic housing, so the contact that moves power from the input to the other terminals out doesn't touch the terminal. Time to order a new switch.

Sanded off all the filler that was clearly visible under the paint on the inside of the tail housing. It had clearly broken in the typical place, I thought that maybe someone had repaired it with fiberglass because I could see the pattern of cloth, but I am thinking now that someone just imbeded the cloth in the filler or else didn't properly harden the resin. Anyway I removed all the old filler and properly glassed it up. It'll cure for the next week until I get down to my sister's again at which point I will fix up the rest of it and drill a new hole for the bolt that attaches it to the seat.

I also replaced the tail light assembly. I was just going to swap out the cracked tail light lens for an undamaged one I had in my box of spares, but when I took it off the inside had been damaged by water and I ended up swapping the lens and the base.

MauiK3 · « **Reply #24 on:** March 18, 2018, 11:16:19 AM »

These projects can't be about profit, either you want to do it or you don't
I don't think I could ever get my $$ out of the K3 even if my wife would let me try.

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Author Topic: My first 750: '76 CB750F (Read 20868 times)