Author Topic: 73' CB750 complete rebuild, DONE! just in time to be moving to KODIAK ALASKA!!!  (Read 35956 times)

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Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #75 on: June 24, 2013, 05:46:54 PM »
And last but not least I bought this off a guys who restored a couple CB750’s and he said it was a life saver if you throw a chain, but maybe that was just a sales pitch, but it bolts to the 2 bolts forward of the front sprocket and is suppose to save your case from getting a hole punched in it if you throw a chain?(its hard to see in the picture because its black on black but look close) Anyone ever seen one or use one? It looks like the chain may run on it, but ill know when I put that on. And as you can see my sticker collection from the build

Honda had something similar to that in the 1970-71 era. The idea behind it is/was to make the [broken] chain stay on the sprocket long enough to throw it on the ground behind the bike. Some actually worked: Honda's was thin sheet metal, though, and many got crumpled up from the kinked links of an unattended chain, then actually CAUSED the chain to fail and wad everything up in a mess. They discontinued it in favor of a larger front sprocket with specially-shaped teeth instead. (Those of you who have my book already know this story...).

This one is interesting, though: it looks like it is made from thick enough steel to hold the chain back a little? How thick is the metal around the sprocket?

heres a few more pictures of the one i got and youre right hondaman, its thick steel about 1/8 inch (after a few thick coats of paint) and i had to take mine off because with the chain it would hit, it looked like the holes weren't line up perfectly and with the thickness and stand off distance it would just rub. as you can see it looked like someone had the same problem, again maybe the guy was trying to make a few bucks and awned it off on me. i dont think ill be riding it hard enough to really need one but it would have been a little extra insurance, but oh well.

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #76 on: June 29, 2013, 05:40:15 PM »
got in my flawless never used chrome breadbox aircleaner today now just waiting on the repop intake boots from the guy in germany  hes seems very proffessional and said it should take 10-20 days to get here and i only paid 32$ for them all im digging the breadbox look and i plan to block off the top 75% of the box to help eliminate the  cross draft issue

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #77 on: July 03, 2013, 07:32:39 PM »
SHE RUNS!!!! well mostly, but i finally got her started today!! what a great feeling, followed by 3 issues,

#1 almost every time i try to start it i blow the a 30A fuse between the battery and starter solenoid i think something may be bad on the ignition circuit, like the condensers, or something in the points, or maybe a bad coil. any thoughts?

issue #2 after i had it funning a few times i notices the pipes from #1 and #4 were not hot at all, so they aren't firing, i suspect  again points, condenser or coil since when i got the bike it did not run and i have not changed the points or condensers, but EVERYTHING on the bike is new, including coils and wires and caps and plugs. all my wiring is custom and run with micro switched and relays, hell i even ran a relay to the starter solenoid. again does anyone have any thoughts? i tried to swap the condensers but now i cant get past the fuse blowing.


issue #3  my carb bowls are leaking and it appears to be from the tops where the bowl should be sealing. i had the carbs rebuilt because i dont know much about them, and so again any help will be greatly appreciated.

i have a video of the first start, but not sure if ill be able to load it up on here…


thanks a ton in advanced

Offline Thousandson

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Re: 73' CB750 complete rebuild (noobie)
« Reply #78 on: July 04, 2013, 04:44:13 PM »
Sweet build, If your using stock points. Check your wires under your points cover. My yellow, was cracked and was grounding out causing 2 and 3 not to fire.
Current ride: 78' Cb750F

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #79 on: July 06, 2013, 10:26:48 AM »
well i got rid of that fuse between my battery and starter solenoid since i didnt realized how much amps the starter drew and life is much better, i adjusted the floats and now only one leaks out of the vent tube so ill go back and adjust that again. also i took the condensers off and cleaned them with some abrasive cloth and then forgot which one was which so i just put them back on and now 1-4 pipes are way hot and 2-3 are cold even in the florida summer heat. so im pretty sure ive narrowed it down to the condensers and fuse being my big issues. tomorrow i will run to dimecity and pick up new condensers and points since they have them in stock and will try putting in the new ones and see what happens, i hope all 4 start firing because i want to hear this baby roar to life. i noticed that when 2-3 were firing solely it started easier and ran a bit longer, when i had 1-4 firing it didn't start easily at all and wouldn't stay running with out a little throttle, is that normal? or is there a reason 2-3 run better alone?


i ordered my new condensers and was hoping to pick them up on friday, but dimecity is closed for the 4th weekend so i wont be able to pick them up till monday, whick might be good since i have some studying to do and it never gets very far when  i have  the bike as a detraction.. so for the most part its figured out just need  new condenser and my quiet core cone and new collector should be here very soon. hopefully monday night i will have her running on all 4 and get to hear my new exhaust at least mocked up

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #80 on: July 07, 2013, 06:14:24 AM »
so i got my brakes all finished up last night now that my speed bleeder came in and wow  what breeze bleeding the brake are with that thing i am defiantly glad i took all the recommendation and got one although it was a little steep im sure it will last a very long time. also i was back and fourth on what brake fluid to use, either dot4 or the controversial dot 5 i ended up going with the tried and true DOT 4 partly because i had a bottle in the garage and as a military guy leaving next summer for a new duty station i cant bring all these paint and chemicals and lubes with me unless i drive them there my self, the movers wont take them. so since i had some one hand and wanted the best and most stiff lever i could i went with DOT 4. i did have one little leak from my pressure switch on the Y fitting on the triple tree but i got a few turn on it and it seems to be holding. i i think it still needs a little more cranking but until i can get a deep well socket it will be fine since its not dripping.


and tomorrow i think my come engineering package will be here and ill be able to go pick up my new condensers so i will keep up on my thread here.

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #81 on: July 07, 2013, 06:22:20 AM »
oh and also i got my intake boots from the guy in germany on ebay (which a few others have used on here) and he was great to work with and shipping was very quick considering they came from germany and seem to fit in the bread box perfectly i am over all very happy and would recommend him.

and also if i didnt mention it before i would also reccomend POSH at http://www.posh-factory.com/index.htm  they were awesome and both places there was no language barrier problem. i also wanted the internal throttle from posh, one of the only 7/8" internal ones i found but didn't want to pony up the money


and after the switches from japan and the boots from germany i cant believe what a ri off shipping is here in the US  i think shipping from both places was around 6-8$ each and both got here in about 10-12 days not to bad considering, i hate paying 20+$ shipping from 2 states away...

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #82 on: July 10, 2013, 05:11:42 PM »
Got my points set right and decided i would ghetto rig a few supply and take it on a few laps i realllly wish i could post a video on here because i got a couple, but they are just to big.  but heres a few pictures of my short ride and the exhaust i still need to get put on and the mock up paint job im planning ill see if i can figure out a video link or something

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #83 on: July 12, 2013, 01:41:20 PM »
tank and seat is at the paint shop should have it all back in about 10 days! and gives me enough time to get my timing  set and all the little odds and ends done

Offline cheftuskey121

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Re: 73' CB750 complete rebuild (noobie)
« Reply #84 on: July 12, 2013, 04:44:30 PM »
its looking great man! love the "photoshop" too ;)

Offline Vinhead1957

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Re: 73' CB750 complete rebuild (noobie)
« Reply #85 on: July 12, 2013, 05:12:08 PM »
This would be a like button!

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #86 on: July 28, 2013, 06:50:35 PM »
well since it has been  awhile i figured i would  throw up an update on here so i dropped off my seat and tank for paint and just picked it up today and it looks great, i refitted the petcock  and added a little fuel to make sure it was nice and tight well it was not! but that wasnt the worst part, as a rolled the tank a nice steady stream came pouring out of the back so a little investigating reveals a little hole int he bottom of the tank!!!! so WTF everything was going so well. tomorrow i am taking my tank to get a nice thick liner and the hole fixed by my painter for $50 and hell tough the paint up  as needed. this ruined my whole day! as you can see the hole is outlined in red and the other picture is the scheme  i chose but the seat still needed to be clear coated in that picture

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #87 on: July 28, 2013, 06:52:39 PM »
also today i got the block off plate i made for my air box back along with my seat and tank and heres what it looks like. its just a simple bent piece of aluminum and looks cool through the holes in my breadbox. also got my new latch and gas cap seal installed

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #88 on: July 28, 2013, 07:01:18 PM »
Heres what some possible paint ideas we were throwing around but i couldn't decide and didnt really like the numbers, although i did originally want them. As you can see we looked at a bullet in the middle, black number or white numbers, but in the end i just had him go clean and simple and will either get my own numbers made or just put them on the oil tank. anyone have thought or think i should have gotten the numbers?


so thats what is new with the bike but ill be out of town for awhile and wont be making any progress but the past couple days i took the carbs apart, which entailed

- reset my float levels
-re bench synched
-and found 2 bowl drains cracked, i tried the heat shrink trick, but it didn't wok for me, so then i broke out the soldering iron and pipe solder and the solder job isnt pretty but seems to be holding up pretty well and it really wasn't very hard.
-got my new plate and linkage in and got that all put on

also the exhaust and cone is on the bike temporarily and let me tell you, between the blocked off airbox, the carb work and timing and the back pressure from the quiet core cone, the bike starts the first push of the button every time!! its amazing how well is sounds!

Offline gantt

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Re: 73' CB750 complete rebuild (noobie)
« Reply #89 on: July 29, 2013, 06:33:21 AM »
Wow man. Its coming together nicely.  I can't wait to have my own cb to dig into. I really like the muffler.

Offline iron_worker

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Re: 73' CB750 complete rebuild (noobie)
« Reply #90 on: July 29, 2013, 06:50:13 AM »
I think you went with the right choice on not putting on the numbers. I'm personally a fan of clean/simple lines. I think less is more in most cases.

IW

Offline gantt

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Re: 73' CB750 complete rebuild (noobie)
« Reply #91 on: July 29, 2013, 07:20:28 AM »
No numbers!!
+1^^^ Cleaner look.  Love the color scheme

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #92 on: July 31, 2013, 03:18:30 PM »
thanks all for the kind words i just got my tank back with the liner and all is well again its pretty nice stuff he put inside the tank and he guarantees it! so for 50$ im happy! but now the bad news i did a quick lap up and down the block and its running a little rough, i blew my cone off the end and dinged it up (i deserve it since it was just slipped on and i wasn't totally surprised it blew off.) Also i did my new fork seals many months ago and cheaped out when i should have bought a new fork piston and now i have a pretty severe leak from one leg heres a picture of it! so when i get back from a trip i will be ordering a new one and getting that whole mess and big project fixed up, im not excited about having to bleed my breaks again. i was thinking, does anyone think i can change one out with out completely disassembling the front end?

i am thinking i may try to drain the fork oil and  pull the front wheel off, then loosen the bottom retainer bolt and slide the old piston out and just  slide the new one in. possible?!!? maybe… am i going to try… probably! im just sad to be leaving all i want is to get the bike up and finished!

Offline grcamna2

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Re: 73' CB750 complete rebuild (noobie)
« Reply #93 on: September 24, 2013, 03:03:23 PM »
Great Job on that CB750 !  ;)
 I wonder if you've been blowing the main fuse because some of your ground connections to the frame(the main ground & the few other harness grounds)being not to clean ? possibly paint that needs to be cleaned off the frame to get a solid metal to metal connection ? I'm just thinking outloud...
75' CB400F/'bunch o' parts' & 81' CB125S modded to a 'CB200S'
  I love the small ones too !
Do your BEST...nobody can take that away from you.

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #94 on: September 28, 2013, 05:28:01 AM »
Great Job on that CB750 !  ;)
 I wonder if you've been blowing the main fuse because some of your ground connections to the frame(the main ground & the few other harness grounds)being not to clean ? possibly paint that needs to be cleaned off the frame to get a solid metal to metal connection ? I'm just thinking outloud...
thanks grcamna i did find the problem with my fuse "well i got rid of that fuse between my battery and starter solenoid since i didnt realized how much amps the starter drew and life is much better" <-- thats from one of post posts earlier, i just put a straight wire in that spot and presto! all is good again.


also i took the whole front end off and apart 2 nights ago and swapped out my fork tubes. i really didn't want to have to do it but i am hoping it stop the seals from leaking, plus one tube had a really deep area of corrosion. so on thursday im trucking it down to a shop to have them weld up my cone and headers then ill take it about 3 blocks down to my really good bike guy and were going to do a proper sync on the carbs so hopefully in a week or 2 it should be on the road!

me and my girl are headed off to biketoberfest in Dayton for a long weekend in october and i really wanted to take the honda but it wont be broken in or tested by then, plus with my seat i cant 2 up on it so well be taking the old reliable V-star. anyone else going to be out that way?


sorry i have been neglecting posting on here by i was gone for a few days due to work and then i had to go to seattle for 2 weeks and just havent had time to get on here much. but i am back at it and hoping by the end of next weekend i will be riding!! time to think about getting some plate put on it!

Offline Harsh

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Re: 73' CB750 complete rebuild (noobie)
« Reply #95 on: September 30, 2013, 05:16:15 AM »
I have been following your build for a while now.  You have done some great work.  I am nearing completion on mine and was wondering where you purchased your halogen headlight from?

Offline iron_worker

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Re: 73' CB750 complete rebuild (noobie)
« Reply #96 on: September 30, 2013, 07:47:24 AM »
If that is a huge gouge in that one fork leg then there is no way it will ever seal on that. That gouge will eat seals for dinner. I had to replace my fork tubes on my build due to similar gouging/marking. Maybe that's what you mean by "fork piston". I got my fork tubes from CMSNL. CycleX also carries them for a pretty good price but they were back ordered when I needed mine.

You shouldn't need to bleed your brakes again I don't think. You should be able to completely remove your caliper but keep it attached to the line and just tie it up out of the way (to the lower triple or something) so it's not hanging off of the line itself.

Just keep reminding yourself not to take shortcuts just because you're close to the finish line! I know it's difficult but you'll almost always pay for those shortcuts somehow later.

IW

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #97 on: September 30, 2013, 04:18:51 PM »
I have been following your build for a while now.  You have done some great work.  I am nearing completion on mine and was wondering where you purchased your halogen headlight from?
hey harsh thanks for following and  as for the light i got mine through cb750supply but vintagecb750.com has them too for about 32$ or so, but any 7" light will work if you buy ne on amazon or any auto site. i was just ordering some stuff anyways so i added that too. but i could really tell a difference when i plugged it up in the house. and i was browsing your build today and it looking awesome! keep up the good work i will follow!


If that is a huge gouge in that one fork leg then there is no way it will ever seal on that. That gouge will eat seals for dinner. I had to replace my fork tubes on my build due to similar gouging/marking. Maybe that's what you mean by "fork piston". I got my fork tubes from CMSNL. CycleX also carries them for a pretty good price but they were back ordered when I needed mine.

You shouldn't need to bleed your brakes again I don't think. You should be able to completely remove your caliper but keep it attached to the line and just tie it up out of the way (to the lower triple or something) so it's not hanging off of the line itself.

Just keep reminding yourself not to take shortcuts just because you're close to the finish line! I know it's difficult but you'll almost always pay for those shortcuts somehow later.

IW

and to Iron_worker yea you are absolutely right that gouge was WWAAAYY DEEP and when i hit a bump would  rub on the seal and start to leak, even the other side which only had minor pits, nothing i was worried about, but did eventually leak. so i ordered new tubes and got them put in last weekend. it wasn't hard to do but i had to take the front brake off with out bleeding as you said, then i zip tied it to the frame and then pretty much disassembled the front end and  re built it all with the new tubes. it was really hard, just took awhile.
As you said too NO SHORTCUTS and i learned early on with a few things like paint vs powder coat, and 2 sets of wheel bearings "the poor man pays twice" so trying to save a buck or 2 isnt worth it, just spending money on the right stuff and getting it done the first time is always the way to go.

but on a bright note i am having my exhaust welded up thursday or friday and then straight to getting the carbs synched and tuned with a guys who knows what hes doing and ill be there to watch and learn since as i have stated before am a very novice when it comes to carbs, let alone 4, makes me feel for my buddy who has a valkyrie with a carburated 6 cylinder in it! so i think it will be on the road in 2 weeks or less!! at least i have my fingers crossed!!

Offline Harsh

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Re: 73' CB750 complete rebuild (noobie)
« Reply #98 on: October 01, 2013, 04:03:52 AM »
I have been following your build for a while now.  You have done some great work.  I am nearing completion on mine and was wondering where you purchased your halogen headlight from?
hey harsh thanks for following and  as for the light i got mine through cb750supply but vintagecb750.com has them too for about 32$ or so, but any 7" light will work if you buy ne on amazon or any auto site. i was just ordering some stuff anyways so i added that too. but i could really tell a difference when i plugged it up in the house. and i was browsing your build today and it looking awesome! keep up the good work i will follow!

Thanks for the info.  I still run the stocker and it is pretty dim and very yellow. 

Offline USCG_C130

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Re: 73' CB750 complete rebuild (noobie)
« Reply #99 on: October 18, 2013, 06:29:35 AM »
My little voodoo child is alive and riding well, took her out on her inaugural ride yesterday/last night and put about 33 miles on her with out a hiccup! except when i got home the battery was low and i had to kick it, so i charged it last night and will see what happens. but man this honda is so much fun and already had 2 people come up and start talking to me about it. so here it is with the seat and exhaust on it, i still need to polish her up and get a proper seat pad made because the one have on there is just a temp pillion for my other bike but it works  for the short term.

as for the carbs i had my mechanic do a proper synch and  he ended up with 115 mains 40 slow and the stock JN position which i believe is 4 and the air screw out about 1 1/2 turns. she doesn't like cold start but once she warm, she runs just fine.

and with everything tuned and the exhaust welded on the bike is sooooo quiet,  i wish it was a little louder cause the noisiest part is the same chain. lol i rode with my harley buddy last night and he couldn't believe how quiet the bike was. but here is how it sits now

and im happy with the tail light it is super bright and not very noticeable. you can barley see it sticking off the back of the lower edge of the seat