Topic: My first 750: '76 CB750F

[seanbarney41]

Danny, I think I have a solid tail piece.  Let me know if you want it.

[Bankerdanny]

 Thanks Sean. The one I have should be fine. I'm going to repaint it anyway.

[Bankerdanny]

Dropped it at Moto Guild today,  the real work starts next week.

[Bankerdanny]

Installed the new ignition switch and seat lock. I now have power to the lights. Starter switch appears to be bad, no click when I press it, but it turns over when I short across the solenoid. Pulled the carbs. Nice and clean inside. Main jets are 125's so I may have to re-jet. Slows are the stock 40's but are completely blocked. The main jets are all clean.

[Jerry Rxman Griffin aka MuthaF'er]

Danny, what intake and exhaust mods did the PO do to warrant an increase of 20 on the mains?

[Bankerdanny]

It had pods and. Kerker muffler on the stock header. Nothing that would warrant a jump like that in my opinion.

[seanbarney41]

If needle clips were never changed/adjusted, 125 is about par for the pod filter course.  Hell, I have 130's in my orange f bike right now with HA breadbox and a wide open Kerker.  K&N dropin airbox filter and Kerker would be rich with 125's, but I bet it would rev out ok.  Don't forget, cb750 came with 120's until 1971 and the only difference was good exhaust, more ignition timing, and VERY slight cam differences.  Save those 105's for emissions testing.

[Bankerdanny]

Since I am going back to the stock airbox and it remains to be seen which muffler replaces the rusted out Kerker I will probably order a stock set and maybe 110's.

[Jerry Rxman Griffin aka MuthaF'er]

Danny, I think that's probably a good plan to start with. My 812 kit, stock head with Yoshi Daytona cam, K&N, Kerker at 6900' had 115's and it ran slightly rich.

Enjoying watching this 

[Don R]

 My 76F with the open center glasspack muffler liked 110's. We went back to stock on the other settings. I did the Hondaman mod. on the advance springs too.

[Bankerdanny]

I haven't updated this in a while even though I have put updates in the 'What did you do to your bike today" thread.

Yesterday was ultimately a banner day for the 750 project, although it started with some panic.

I have been wanting to get the bike to run just to make sure it will and that it doesn't make any alarming noises. I got it to pop a couple times last week, but then put is aside to get the 550 cleaned up so I can ride it.

So yesterday (Sunday 4/22) I tried to start it again with no luck. I decided to pull the plugs and they were in pretty bad shape, #1 was very black and the others were also showing that the last time it did run it was very rich (the end of the #2 cap is also broken up). That makes sense given the 125 main jets it had in it (stock is 105). The #4 plug was really hard to turn, I was afraid it was going to break while I was removing it.

I eventually got it out and was concerned that maybe someone had cross threaded it into the head, which was why it was so hard to unscrew. I cleaned and gapped it like the others and screwed it back in, but it just didn't seem to want to tighten. I turned for what seemed like a long time, but it never got tighter.

I thought I was screwed and would have to pull the head and Helicoil it, but before I did anything I was determined to get it to run. So I hooked the aux tank up, touched the yellow/red wire to the + terminal (the switch is busted, the new internal housing is due today) it started to pop and finally caught. It blew some seriously black smoke out the muffler along with dust and debris. It didn't want to idle, but it did rev smoothly, although I only went to about 4k. Mission accomplished I shut it down.

When I was done I decided to take one more stab at tightening the plug and low and behold it turned about 1.5 turns and stopped. So maybe I just gave up too soon. I'm going to see about sourcing another head just in case, but I appear to have dodged a bullet.

Other activity was getting the front bleeder screw to loosen and not break and pumping the brake piston mostly out. I have to remove it, but based on what I can see, a new piston is in order along with a seal and pads.

The rear caliper is the bigger challenge. I think there is a picture on page 1 of this thread, the bleeder was snapped flush with the caliper body. I tried drilling it mostly out with the drill press, but no joy. At this point I am just going to drill and Helicoil it to fit a new bleeder since replacement caliper assemblies are not easy (or cheap) to come by.

Now I need to put together a plan of attack and dig in. My goal is ready to ride in 1 month.

[Jerry Rxman Griffin aka MuthaF'er]

Last I heard (it's been a while!) the Speed Bleeder guys can attempt to remove the bleeder. Not sure if they could/would install a helicoil etc? but I love their product.

The rear overhaul kit is available from SiriusConInc.com and one kit includes both pistons. Nice kit.

Looking forward to your first ride   

[Bankerdanny]

Been ordering parts, a bunch should come in over the next few days and this weekend will (hopefully be productive).

I pulled the exhaust earlier this week and then started on the fork seals. The right side seal has been replaced and I did some basic polishing of the lower. I wasn't looking for a mirror shine, just a step up from the peeling clear coat and corrosion it had to start with. I only get a couple hours a night after work Mon-Wed at Moto Guild and I have also been helping a college kid with his CB360 project (he was able to start it Tuesday) so work moves slowly. Wednesday I wasn't able to get in, so the left leg will get done Saturday or Sunday.

New tires and tubes should arrive tomorrow (Friday 5/11) so I plan to install them over the weekend. A tapered steering bearing conversion kit is on the way too and night arrive by Saturday.

Godffrey is shipping me phenolic pistons and new seals for the front and rear brake calipers, Scottly just shipped me a weldless frame kit, and I bought an OEM muffler (which actually came off of an early 750A, which used the same frame and 4-1 exhaust as the 750F) to go with my OEM header from a guy in the Atlanta area that should arrive next week.

I need to check my schedule, but I am thinking next Tuesday and Wednesday next week are going to be vacation days so I can put in full days at Moto guild. He's shutting down for the month of June to move the shop a few blocks west of his current location, so I need to be mostly done (preferably all done) and move the bike back down to my sister's garage to wrap up.

Right now my to-do list (in no particular order) is:
- Order and replace throttle cables with shorter ones based on the Euro bars I am using in place of the stock tall bars. Might need to do clutch cable too.
- Order and install new braided steel brake lines
- Drill bars and reinstall controls
- Clean and paint turn signal bracket
- Install steering bearing conversion and paint up the triples
- Rebuild and paint front and rear calipers, install new pads
- Install new tires and tubes
- Buy and install new chain (and maybe sprockets pending inspection)
- Pull carbs back off and check the float heights.
- Adjust the misaligned inner airbox to carb rubbers and reinstall bottom of airbox and new filter.
- Oil and filter change
- Check point gap (already gapped the plugs)
- Check valve clearance
- Reinstall headlight shell and try to get wires tucked neatly back into the box between the downtubes
- Finish cleaning out the old tank coating. Check for any additional leaks and decide if I want to braze them up like the others, or just re-seal (which I am going to do regardless) and leave them be.
- Eventually strip and repaint the tank and also repaint the tail. Color yet to be decided. it was originally Sulfer Yellow, but since it won't be a show bike I can paint it any color I please.

[Bankerdanny]

Ordered a pair of new sidecovers yesterday from Frankenfrankenstuff and my tapered bearing kit arrived. New tires and tubes are waiting for me at my buddy's hardware store. The new to me OEM muffler is due to be delivered on Tuesday.

[Bankerdanny]

New back tire, had to cut the old one off. Cleaned several years (decades?) of crud off the hub. Popped out the old fro t caliper piston too, a new phenolic piston and seal from Godffrey is waiting to be installed once the caliper is repainted.

[Don R]

 I like the ones with the sidecovers painted to match.  A non stock color with the stock stripes would be cool.  That would free you up to use an awesome new car color with new style paint. The tiger eye pearl brown from my wife's 2013 accord was awesome and my painter liked it because it's easier to put on than the Honda candy colors.  That looked good on a k1 but a trip through the car lot could be an eye opener.

[Bankerdanny]

Time to catch this thread up with the updates I have posted in the "What did you do to your bike today" thread.

Here is my to-do list from the other day:

Right now my to-do list (in no particular order) is:
- Order and replace throttle cables with shorter ones based on the Euro bars I am using in place of the stock tall bars. Might need to do clutch cable too. Cables ordered and should be here by this weekend
- Order and install new braided steel brake lines
- Drill bars and reinstall controls
- Clean and paint turn signal bracket. Did this, but the bracket had been damaged and badly re-welded at some point. I can't decide if I want to fix this bracket or just find a replacement. I have a welder in my sister's garage, so it isn't a problem to fix myself, but there is the time aspect of having to drive down there vs just buying a good one and having it shipped
- Install steering bearing conversion and paint up the triples
- Rebuild and paint front and rear calipers, install new pads. I have the new pistons and seals for both front and rear and pads are on the way
- Install new tires and tubes
- Buy and install new chain (and maybe sprockets pending inspection). chain and sprockets ordered and will hopefully arrive and be installed this weekend
- Pull carbs back off and check the float heights.
- Adjust the misaligned inner airbox to carb rubbers and reinstall bottom of airbox and new filter. I need to set the floats before I put the bottom part of the box back on
- Oil and filter change
- Check point gap (already gapped the plugs)
- Check valve clearance
- Reinstall headlight shell and try to get wires tucked neatly back into the box between the down tubes
- Finish cleaning out the old tank coating. Check for any additional leaks and decide if I want to braze them up like the others, or just re-seal (which I am going to do regardless) and leave them be.
- Eventually strip and repaint the tank and also repaint the tail. Color yet to be decided. it was originally Sulfer Yellow, but since it won't be a show bike I can paint it any color I please.

[Bankerdanny]

In addition to the above I received the OEM muffler I picked up from a guy in Atlanta. It is big and heavy (11 pounds) but it is in perfect condition and cost $100 less than I would have paid for a basic MAC replacement.

[RAFster122s]

I just joined the party...been away a long time now...
I have a pair of Kerkers I was told was for a 550 or could go on a 750. The baffles are nothing more than wire cages for the packing and it has been so long... I believe they do not have end caps. They are in pretty good shape, not perfect or for a real nice bike but they could polish up well I think. The one Kerker badge has a rivet sheered off and needs replaced, or were they screwed on.
Been too long, they are in a box in storage building.
I would tell you this after you picked up the OEM muffler.

Interested in some measurements and pics or is it a pass?

David

[Bankerdanny]

Measure the opening where it attaches to the header. The 750 is bigger, 2.5 inch.

Sesnbarney would happily take one of those Kerker badges off your hands.

[Bankerdanny]

Wires for controls run through the bars. Finally time to start hooking all the electrical back up.

[Bankerdanny]

I just realized I didn't add a picture of the new rear tire. It's a Metzler Sportec Klassic. Both the front and rear are now stock sized replacing 4.10 and 5.00 tires respectively.

[RAFster122s]

Danny,
If you want to bling out your controls, aluminum anodized body right?  Use some Greased Lightning degreaser and soak the bare bodies for up to 15 minutes usually and all your old anodizing will be removed. Wipe off the black smut and you will have a dull aluminum finish that can be polished to mirror brightness.  The anodizing helped eliminate any glare from the controls, most likely reason they were anodized black.
Polished aluminum will be brighter than chrome and renewable with some elbow grease, if you can reach the parts completely.

Just a thought.

Another option for calipers and controls is hard teflon coating as it approximates the black coating from Honda on the later calipers that were twin pot. Rinses clean better than powder coating although it is more expensive than powder coating unless you have a lot of stuff and they give you a volume discount.

[Bankerdanny]

Right now my focus is getting it on the road. I'm looking to sell my 550 and would like this one ready to go when it happens.

I like the look of the black controls. Mine have some of the typical fading, but that is OK for now. If I decide they need to be a nice deep black then I will consider painting or powder coating or even just buying some repops. They are under $50 each.

[calj737]

...aluminum anodized body right?  Use some Greased Lightning degreaser and soak the bare bodies for up to 15 minutes usually and all your old anodizing will be removed. Wipe off the black smut and you will have a dull aluminum finish that can be polished to mirror brightness.

Sorry to disagree, but, a degreaser won't effect a part that's been truly anodized. Anodizing is not a surface treatment, it impregnates the surface of the material to a thickness. Some chemicals will remove anodizing, but even brake fluid won't damage it sometimes which is why you'll often find it as a treatment on perches.