Author Topic: 1978 CB750 Codename "Athena"  (Read 1874 times)

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Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #25 on: June 19, 2022, 09:06:52 AM »
Oh f**k…

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #26 on: June 19, 2022, 09:20:19 AM »
Well the no roll can be the flat tires or bearings yes or stuck back brake(pull the wheel off to find the cause...) or a stiff or rusty chain(can be loosened up by cleaning and the lube as a temporary solution or removal of the chain)
Thanks you!  All of that needs to be addressed soon anyways. 
I’m thinking I need to walk away from the bike for the day.

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #27 on: June 19, 2022, 02:13:47 PM »
... I didn't walk away from the bike.  I pulled the plate and cleaned out under the points cover with a wire brush for about an hour.  I had a second plate with points and condensers on it that was conveniently located in the back box.  I think that they took them off bc the screws were stripped beyond reason.  I switched out the screws and installed it.  I then oiled the crap out of the chain and tried to flex it around a bit.  I ended up airing up the tyres as well and surprisingly they held air so far. The bike moves a little easier now but I need to pull apart the rear brake to see whats going on yet.  Its a hassle bc I can't get the bike on its center stand bc i cant get it to roll well enough and I can't get it to roll well enough bc i need to take apart the brake.  I am going to see if i know anyone with a motorcycle lift that i can use.  I only have 2 friends who ride and neither work on their own bikes lol.  Thats how I got this one, guy wanted a project but doesn't want to learn how to do the project lol.
I got most of the wiring done today aside from the front lights (bc there isn't any)  I was able to turn the ignition on and have the neutral light come on (neutral switch works), able to turn the starter over with the ignition on (with the makeshift start button that was on it already) I was at the point to where i was going to check the points and static timing before firing it up for the first time and everyone can see the state of the points.  I have the other ones installed and now i just need to set the timing.  I don't own a timing light and i am not sure when i can buy one yet but i hope that I can get it set well enough to get it to start and run a little bit with the first timing. 

Offline Stev-o

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Re: 1978 CB750 Codename "Athena"
« Reply #28 on: June 20, 2022, 09:33:35 AM »
Oh f**k…

You said it! About the worst I've ever seen a points area!!
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #29 on: June 20, 2022, 10:53:25 AM »
It looked like a deep sea shipwreck.  That’s what I get for having had carbs that were in good shape.  You always pay sometime down the line.
Perhaps someone overfilled the points reservoir 😂

Offline SOHC4 Cafe Racer Fan

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Re: 1978 CB750 Codename "Athena"
« Reply #30 on: June 20, 2022, 11:48:00 AM »
Wow, those points look like they've been in or near salt water.
1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
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Offline Stev-o

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Re: 1978 CB750 Codename "Athena"
« Reply #31 on: June 20, 2022, 11:48:55 AM »
Perhaps someone overfilled the points reservoir 😂

Ha...no doubt!
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #32 on: June 20, 2022, 12:24:34 PM »
         I busted the Dremel and wire wheels for that one.  I was lucky to have the spare plate with the points and condensers on it.  I think it was removed originally because all of the screws were stripped out and you couldn't adjust it at all.  I ended up using an extractor and put new M4's in it (allen).  I was considering going over today to get it timed and try to start her up but I got one hell of a sunburn yesterday and the slightest bit of warmth sets my skin on fire.  I need to brush up on youtube how to set the timing anyways.  I am pretty fortunate that there is at least 3 videos that show that, in depth for my particular motor.  I am probably going to buy a cheapy strobe from amazon this week, I think I can swing the $30 since I quit the cigarettes.  I may also have a possible person who can help me move the bike to my house.  Its a older guy in my department that is on my crew.  This guy is a literal millionaire (he does the electric and equipment for movie theaters), he started working at my place bc  he wanted to get an extra income to build up his Nova... I have been to his house to use some machines and his mancave in the barn is bigger (and nicer) than any place i have ever lived period.... But at any rate, I know he has a fleet of trailers at his house, my only worry is that he doesnt have one small enough hahaha
          My ultimate goal is go get the bike running and running well and at least ride her a few times as weather permits.  My job gave me the OK to use the powder coat line this winter as long as i pay for consumables and matierials and as long as i do it on my own time.  E-Coating, I have to pay to have it put on a carrier going into the machine and they are not liable for whatever happens.... and thats fine.  Solid lubricants like teflon or graphite.... well thats my department and... who knows what could happen with that... perhaps I accidentally CeraKote my whole bike LMAO

Offline Stev-o

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Re: 1978 CB750 Codename "Athena"
« Reply #33 on: June 20, 2022, 02:13:47 PM »
      ... perhaps I accidentally CeraKote my whole bike LMAO


Ha!  You are funny...
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #34 on: June 21, 2022, 01:26:04 PM »
if it were an older 70's I would probably consider it lol.  I'm not really in love with the shape of my fuel tank and how it transitions to the seat.  I don't know if it would be a terrible amount of trouble to use a different tank and seat, I'm still trying to get the thing started lol.  I probably won't be getting over to work on it today though, My other grandfather passed away this morning and then I got a decent amount of bad news at my doctors appointment this afternoon.  Looks like it will be another night of watching other people build bikes on youtube lol

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #35 on: June 23, 2022, 02:14:36 AM »

got her started...

I only caught the bike on fire twice before i got it to idle steady.  I did have a fire extinguisher handy but fortunately i was able to snuff it out with a cloth both times.  The starter clutch is going bad so I decided to kick it over to try to start it.  I sprayed it with starting fluid and kicked it one time and it roared up immediately, it scared the hell out of me because i wasn't expecting it at all so i managed to fall into the bike and gash my knee on something or other (that was probably rusty) She kept starting up pretty consistently with the starting fluid so i decided to put the tank on and put a gallon of premium in.  I let her idle for about a half an hour before the battery died (generator isn't working yet apparently)  I then celebrated with way too many beers and now i am not going to go to work this morning. 
I guess next I am going to look into the generator system and check it out, see if theres anything obvious going on.  I will probably change the oil again in a few days and filter it to look for any metal flakes.  When I had her idling I sent video clips to everyone that i know, no one was nearly as excited as i was... especially the PO, he seemed a little salty actually.  He simply responded "ok" to the video.

Offline newday777

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Re: 1978 CB750 Codename "Athena"
« Reply #36 on: June 23, 2022, 03:24:18 AM »
WOW! That points plate and housing has barnacles growing.... worst I've seen yet. You sure have your hands full on this bike,  being it's your 1st.....
Be sure to get a new gasket on the cover before riding/storing in the wet environment. As you can see, moisture in there is not a good thing.
I'm sorry for the loss of your grandfather and the news from the doctor.
Did your dog get run over too? There's a song in the making.......
Well, you got it fired up since I was last on @ a week ago.  Did you clean out the gas tank of crude (and rust)?
How did you end up cleaning the carbs?
As a observation, when you run the bike more than a couple minutes,  be sure to have a fan blowing on the front of the motor to cool it. It's an air cooled motor and needs air flow over it while sitting working on it. They don't like overheating.......
It's good to hear you found someone with a trailer to help you out to get it home. Hopefully it works out. 
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #37 on: June 23, 2022, 04:15:15 AM »
WOW! That points plate and housing has barnacles growing.... worst I've seen yet. You sure have your hands full on this bike,  being it's your 1st.....
Be sure to get a new gasket on the cover before riding/storing in the wet environment. As you can see, moisture in there is not a good thing.
I'm sorry for the loss of your grandfather and the news from the doctor.
Did your dog get run over too? There's a song in the making.......
Well, you got it fired up since I was last on @ a week ago.  Did you clean out the gas tank of crude (and rust)?
How did you end up cleaning the carbs?
As a observation, when you run the bike more than a couple minutes,  be sure to have a fan blowing on the front of the motor to cool it. It's an air cooled motor and needs air flow over it while sitting working on it. They don't like overheating.......
It's good to hear you found someone with a trailer to help you out to get it home. Hopefully it works out.

Thank you I appreciate it.  I ended up just hand cleaning the carbs out and replacing the gaskets.  My ultrasonic doesn't work anymore apparently.  The gas tank wasn't bad so I just did several rinses and used a bottle brush.  I dried it out with a hair dryer after the last rinse and put a bit of light oil inside to shake around and then left it upside down to drain for a few days.  I put an inline fuel filter on it to make sure in case that wasn't good enough.
I was so excited i didn't even think to put a fan on it, I will def do that today when I go over, thank you.  Do you know what the normal operating temp should be for the engine or maybe the upper limit?  I have a infrared thermometer i can use to make sure i don't go too hot.
I ended up buying a tarp and bungees to keep it covered up while its partially disassembled.  I still have to tuck the wiring away, get an air filter, reinstall covers and get new cover gaskets for everything, get new throttle cables and learn how to install them lol, replace the clutch and cables, re build the brakes im sure,  probably the steering bearings and seals, rebuild the forks, get a new chain and also new tyres before i will even consider riding it around.  I also have to learn to ride again... I did dirt bikes when i was a teenager but never a motorcycle.  Even with the dirt bikes, that was 26-27 years ago so basically it will be like i have never ridden anything.
back to the throttle cables... does anyone have a good picture of the cables hooked up so i can see how it was routed?  In most circumstances I snap pictures of stuff before i take it apart but this time i didn't.  I don't even remember the set up on the twist grip either. 

Offline newday777

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Re: 1978 CB750 Codename "Athena"
« Reply #38 on: June 23, 2022, 05:26:56 AM »
I don't have my cable routing pictured.

So for a start here is the service manual link in case you don't have a hard copy.  It should show the cable routing.

https://moto-odejda.ru/file/CB750SOHCShopManual.pdf
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #39 on: June 23, 2022, 07:49:13 AM »
Fantastic thank you!  I had the Clymer manual hard copy and I had digital copies of earlier model manuals  (74-76ish) Most of the photos in the clymer guide are really dark and its hard to discern what is what sometimes.  I am about to head over to the bike and mess around with some of my huge list of concerns.  I did find out this morning that a guy I work with, his father has a 78 cb750 (bought it new back in the day) his father was a bike mechanic for most his adult life but now he is in his 70's and doesn't really ride anymore.  From what the guy said, his father isn't really sentimental over the bike and the hundreds of parts he has accumulated over the years, and he may be interested in selling all the CB stuff including the bike.  That would help me out so much.  I have been searching for a parts bike (or parts in general) on craigslist and market place for a few weeks.  I keep either finding pristine bikes i can't afford or I find a parts bike that it too new. I am not super interested in trying to find a running motorcycle either, I want to find a piece of S... and make it run lol.

Offline tshrey

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Re: 1978 CB750 Codename "Athena"
« Reply #40 on: June 23, 2022, 09:13:47 AM »
I'd take those points any day over having seized carbs  ;) 

After having the bike running for half an hour I would drain the oil to check it, pull the clutch cover and look over the clutch and then put fresh oil in.  If that points area was filled with salt water that stuff has an amazing ability to get everywhere, you want to make sure it didn't get past the crank seal into the motor.

Offline newday777

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Re: 1978 CB750 Codename "Athena"
« Reply #41 on: June 23, 2022, 09:50:02 AM »
Fantastic thank you!  I had the Clymer manual hard copy and I had digital copies of earlier model manuals  (74-76ish) Most of the photos in the clymer guide are really dark and its hard to discern what is what sometimes.  I am about to head over to the bike and mess around with some of my huge list of concerns.  I did find out this morning that a guy I work with, his father has a 78 cb750 (bought it new back in the day) his father was a bike mechanic for most his adult life but now he is in his 70's and doesn't really ride anymore.  From what the guy said, his father isn't really sentimental over the bike and the hundreds of parts he has accumulated over the years, and he may be interested in selling all the CB stuff including the bike.  That would help me out so much.  I have been searching for a parts bike (or parts in general) on craigslist and market place for a few weeks.  I keep either finding pristine bikes i can't afford or I find a parts bike that it too new. I am not super interested in trying to find a running motorcycle either, I want to find a piece of S... and make it run lol.

You're welcome.  That would be a great find if you can get that bike and parts..
Stu
Honda Parts manager in the mid 1970s Nashua Honda
My current rides
1975 K5 Planet Blue my summer ride, it was a friend's bike I worked with at the Honda shop in 76, lots of fun to be on it again
1976 K6 Anteres Red rebuilding project, was originally my brother's that I set up from the crate, it'll breath again soon!
Project 750s, 2 K4, 2 K6, 1 K8
2008 GL1800 my daily ride and cross country runner

Prior bikes....
1972 Suzuki GT380 I had charge of it for a year in 1973 while my friend was deployed and learned to love street riding....
New CB450 K7 after my friend returned...
New CB750 K5 Planet Blue, demise by ex cousin in law at 9,000 miles...
New CB750 K6 Anteres Red, to replace the totaled K5, I sold this K6 at 45k in 1983, I had heavily modified it, many great memories on it and have missed it greatly.....
1983 GL1100A, 1999 GL1500 SE, 1999 GL1500A

Offline MrJackLazarus

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Re: 1978 CB750 Codename "Athena"
« Reply #42 on: July 04, 2022, 04:28:22 AM »
been a while...
mostly because i didn't get the bike moved to my house until the 2nd.  Its good to know that you can rent a small utility trailer from TSC here in town, $15 for 4 hours.  Just needed a 2" hitch and it was all easy. 
Yesterday was my 40th birthday so for my birthday wish this year i asked that people leave me alone all day and let me work on my motorcycle and drink... which i did. 
I cut the rear of the frame under the seat for a new hoop.  I know some people may not care for that too much and possibly get angry about modifying it from original but this bike is not a dime by any stretch... and its a 78... from what i can tell people don't really care much about the CB's after 76.  So I may as well get all my practice in, learn the bike down to the last spring and JIS screw. 
As i was cutting off various brackets and tabs, i was also hitting rust spots with the wire wheel on the drill, then i would just put a little primer on it to keep it from rusting again.    when I am able to pull the whole motor out, i will take the engine inside to live on my workbench for a few weeks and I will take the frame to my work where we have a blasting cabinet that is big enough for the whole frame.  Then i will actually prime and paint it.  I have been hearing good things about the VHT chassis and roll bar paint so I picked up a few cans of that. 
I had intended to just get this bike running and get it on the road asap.  i am really worried about internal engine damage though... mostly piston rings and valves.  she smokes a good bit more than i think she should.  This bike is pretty important to me and i don't want to risk blowing the engine if i can help it.  Aside from that... I need to learn to do it anyways if i intend to keep working on old hondas...