Author Topic: Cb750k1 refurbishment  (Read 12267 times)

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Offline MauiK3

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Re: Cb750k1 refurbishment
« Reply #50 on: May 24, 2018, 07:54:41 PM »
Looking great, you'll really get excited the first time it comes to life!
1973 CB 750 K3
10/72 build Z1 Kawasaki

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #51 on: May 29, 2018, 02:41:31 PM »
Just a little more progress to report. The carbs are rebuilt, and i polished the bowls and tops and got them installed. All the cables are on. The rear wheel is all cleaned up and has new bearings. All 4 exhausts are cleaned up and installed. When i went to install the airbox, i found that the rubbers were cracked and deformed so i had to order new ones. Now its just a waiting game. I need the sprockets and chain to put the rear wheel on, i need the rubbers for the airbox, then it can go on, and im waiting for a new upper brake hose so i can bleed the front brake. Otherwise, its pretty much together.




Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #52 on: June 01, 2018, 09:45:06 AM »
Im ready to try and fire this thing for the first time, but ive run into a snag. Ive kicked the engine over about 50 times and cranked it a little in spirts but the oil light isnt going out. I pulled a few tappet covers and i can look in and see oil dripping onto the cam when i crank it, so i think there might just be an issue with the sensor or maybe the wiring. Im nervous about starting it, though. I wish i had an oil pressure gauge to see if i have oil pressure.  Im going to inspect everything and see if i can figure this out. Any suggestions? This is my 4th cb750 engine rebuild, 8th honda engine rebuild but first that the oil light didnt go out.

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #53 on: June 01, 2018, 10:13:10 AM »
My understanding is that the switch grounds and turns on the light with no pressure, so if i disconnect the wire from the switch, the light should go out. Currently, the light stays on with the wire disconnected from the switch, suggesting its grounding elsewhere. Am i correct on this or am i backwards?

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #54 on: June 01, 2018, 10:33:20 AM »
Problem solved. The light bulb housing was grounding against the tach. Its rubber shield is mostly gone.

Offline SOHC4 Cafe Racer Fan

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Re: Cb750k1 refurbishment
« Reply #55 on: June 01, 2018, 11:30:12 AM »
Also a good practice to run the starter with the kill switch to OFF and allow oil to cycle through the motor, before trying to fire it.  You know that though.
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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #56 on: June 01, 2018, 11:36:39 AM »
Also a good practice to run the starter with the kill switch to OFF and allow oil to cycle through the motor, before trying to fire it.  You know that though.

Yes, i did that. Bike is running great now and no leaks. I just hooked up the vacuum gauges and got the carbs synced up. Now i just have to wait for the last few parts to arrive and i can get thing out on the road

Offline SOHC4 Cafe Racer Fan

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Re: Cb750k1 refurbishment
« Reply #57 on: June 01, 2018, 12:38:44 PM »
Also a good practice to run the starter with the kill switch to OFF and allow oil to cycle through the motor, before trying to fire it.  You know that though.

Yes, i did that. Bike is running great now and no leaks. I just hooked up the vacuum gauges and got the carbs synced up. Now i just have to wait for the last few parts to arrive and i can get thing out on the road

I figured as much.  I left the comment more for newbs who might read it and pick up a good habit.
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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline Stev-o

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Re: Cb750k1 refurbishment
« Reply #58 on: June 01, 2018, 02:15:47 PM »
Glad you found the issue, Dave.  That can be very concerning after a pricey rebuild.  On my last start up, I must have kicked it over 200 times before trying to fire!  3 seconds after firing, light went off, that is so gratifying...
'74 "Big Bang" Honda 750K [836].....'76 Honda 550F.....K3 Park Racer!......and a Bomber!............plus plus plus.........

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #59 on: June 01, 2018, 03:08:37 PM »
My new chain and sprockets arrived today so the rear wheel is finally back on. The carb to airbox rubbers are to arrive tomorrow and the brake line on monday and that will wrap this thing up. As mrntioned, i synced the carbs today. They were pretty close already. Im not sure if it will make a difference that the airbox wasnt on, but i can always do it again if it seems off. I would think that for just syncing the carbs up, the airbox wouldnt really make a difference, but what do i know.  Anyways, heres some update pics. Ill get the airbox on tomorrow and probably take it for a little spin. "I dont need no stinking front brake" will be my famous last words.




Offline Tews19

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Re: Cb750k1 refurbishment
« Reply #60 on: June 01, 2018, 04:23:32 PM »
Looks great Dave! Is the tank and rest of the clothing from Yamiya?
1969 Honda CB750... Basket case
1970 Honda CB750 survivor.

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #61 on: June 01, 2018, 04:28:27 PM »
Looks great Dave! Is the tank and rest of the clothing from Yamiya?

Thanks. All of the body parts are the originals repainted by rj cycle.

Offline SOHC4 Cafe Racer Fan

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Re: Cb750k1 refurbishment
« Reply #62 on: June 01, 2018, 11:06:02 PM »
This is almost ready for a BOTM nomination.
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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline calj737

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Re: Cb750k1 refurbishment
« Reply #63 on: June 02, 2018, 03:13:46 AM »
This is almost ready for a BOTM nomination.
Took the words right out of my mind.  ;)
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #64 on: June 02, 2018, 09:42:41 AM »
Thank you for the kind words

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #65 on: June 02, 2018, 06:32:03 PM »
Today was a day filled with both excitement and turmoil. I got home from work to find that not only did my airbox rubbers come, but so did my brake. The last 2 pieces of the puzzle. I quickly got to work getting the parts installed and front brake bled. This was my first time installing carbs and an airbox with new rubbers and it was so much easier. I dont know why i ever bothered trying to soften old ones in the past. The relatively low price of new ones was totally worth it just for ease of install, let alone the potential performance improvement.  So, with the bike now complete, i proceeded to get it down from the lift so i could take it out for a ride. This is the start of the turmoil. First, the jack that raises and lowers the table broke with the lift still too high off the ground. Theres nothing i could do with it with the bike still on it, so i got my ramp so i could get the bike off. It wasnt too high off the ground, maybe 18 inches or so, but too high for me to guide it down while standing on the ground so i climbed on to ride it down. I started slowly down the ramp. Too slowly because i didnt have enough momentum to keep rolling. With the back wheel still on the table and the front on the ramp, my feet over nothing, the bike stopped. I had nothing to put my feet on so we started to topple over. I jumped off the side and tried to hold the bike up, but my foot landed in a bucket of carb cleaner i had on the floor causing a big spill and i slipped. The bike fell to the ground with the headlight/handlebar area landing perfectly between my superhawk and black bomber. None of the bike was not touching the ground thanks to the fall being broken by the gas tank landing on a gas can i had sitting there.  I was fortunate that the damage is somewhat minimal. The right side mirror broke, the lower pipe that was already dented is more dented, the upper pipe that was not dented is now dented, and the tank is dented and the stripe scraped. No other bikes were harmed, thankfully. My shoes were ruined by carb cleaner and my pride a little hurt as i had to seek assistance from my neighbor to get the bike back on its wheels with damaging it more. I did go ahead and ride it after everything was cleaned up and it ran great. So at least theres that. I was set to list it for sale tomorrow, but now i have to make some decisions. None of the pipes were perfect before, so i dont think the new damage with affect the overall value much. I do think the damage to the tank will take it down a bit so i have to decide if i want to get it repaired and repainted.  Im in a bit of a time crunch as i need this bike sold with inn the next few weeks. I dont know if the tank can even be turned around that quickly. I also have the option to sell it as is, but i need to turn a profit on it, which may be a little tough now. That was a long story and its over now, so here are some pics, both highlights and lowlights.


















Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #66 on: June 02, 2018, 07:23:30 PM »
Ronnie jennings got back to me quickly and hes going to help me out on getting the tank back to its former glory. A bummer, but not the end of the world. The exhaust kind of is what it is, unfortunately. I dont think replacing the pipes will be cost effective. On the plus side, the bike really runs great. I had already filled the tank about half way, so im just going to have to get it out and ride it so i can use up that gas and ship out the tank.

Offline Tews19

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Re: Cb750k1 refurbishment
« Reply #67 on: June 02, 2018, 07:38:30 PM »
Fuc******, I cant imagine how you felt when that all happened. She is still a stunner! So don't worry about turning a profit bud. These machines are more for the enjoyment.
1969 Honda CB750... Basket case
1970 Honda CB750 survivor.

Offline SOHC4 Cafe Racer Fan

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Re: Cb750k1 refurbishment
« Reply #68 on: June 03, 2018, 12:08:55 AM »
Sorry to hear of the ramp mishap.  The bike is still a beauty.

F it, I'm going to nominated it dents and all!
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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline calj737

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Re: Cb750k1 refurbishment
« Reply #69 on: June 03, 2018, 03:18:18 AM »
Great attitude, great outlook, and great to hear YOU didn't get hurt. Bike is a beauty, Dave, shame it can't stay with your blue Beauty Queen  :'(
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #70 on: June 03, 2018, 03:32:19 AM »
Thanks everyone. I keep thinking about how i could have done this or that thing different. Maybe had more patience. Hell, if i had just put the bucket of carb cleaner away, i wouldnt have stepped in it and slipped and i might have been able to save it. I even had a dream about it last night. Oh well, in a couple weeks it will be fixed.

Cal - blue beauty queen?

Offline calj737

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Re: Cb750k1 refurbishment
« Reply #71 on: June 03, 2018, 04:05:24 AM »
Yeah, didn’t you have a blue K with gold rims? Or am I confusing you with another member?
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline 02z06dave

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Re: Cb750k1 refurbishment
« Reply #72 on: June 03, 2018, 04:06:33 AM »
Yeah, didn’t you have a blue K with gold rims? Or am I confusing you with another member?

I believe youre thinking of vegas dave

Offline calj737

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Re: Cb750k1 refurbishment
« Reply #73 on: June 03, 2018, 04:15:35 AM »
Yes I am  :-[
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline SOHC4 Cafe Racer Fan

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Re: Cb750k1 refurbishment
« Reply #74 on: June 03, 2018, 06:36:33 AM »
Your motorcycle has been duly nominated, seconded (and thirded) for BOTM.  Please be sure to post that you accept the nomination in the following thread:  http://forums.sohc4.net/index.php/topic,172446.0.html

Well done!
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
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold