My 1981 Honda CB750K Project Bike

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Re: My 1981 Honda CB750K Project Bike

TOOLS1
Administrator
I feel, for, you on the choke. I have a Kawasaki 750 LTD with CV carbs I am fighting with. It is doing the same thing. Acts just like a vacuum leak.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Yeah, that's exactly what it's acting like. Hoping to get in there tonight and figure out whats going on with it. Now I am wondering if it's not that stupid rubber T connector that connected 2 hoses to the top of the air filter box, it had a big hole in it and I couldn't find anyone that carried rubber T connectors and Honda discontinued it, so for now I put plumber's putty over it and taped it up good with electrical tape.

But for now I plan on helping my grandmother get her little '01 Kymco KZ50 running, my grandfather is a tractor mechanic but doesn't deal much with the CDI ignitions so I'm gonna help them out with it and hopefully will get her hauling ass down the road at top of 38mph, ha!
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Damn bike is pissing me off! it's not the choke, but I pulled the tops off the carbs for fun and sprayed some carb cleaner down them and put them back together. Fired bike up, cylinder 1 wasn't firing. Pulled the plug again, its fouled again so I cleaned it and threw it back in, started it back up and it ran up to 4Krpms and it spat flames and made the #2-4 headers glow red hot! Idk, will the timing make it do this? Getting real old real quick....

Are the stock carbs on these Keihins btw? Think I am getting my hopes up thinking maybe they aftermarket, but I'm pretty sure they aren't.... but I can dream about pods and big exhaust without changing the carbs can't I?
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Re: My 1981 Honda CB750K Project Bike

shinyribs
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I only know of two things that would make a header tube glow. A severely lean condition or retarded ignition timing. I doubt yours is a lean condition as you are experiencing plug fouling. Sounds like your timing is retarded. It is firing so late(retarded) that the combustion process is taking place when the exhaust valve is open. Thats why it gets hot enough to glow. I dont know about these CB motors,but on an old V8 its a sure fire way to burn a valve. Might wanna check that timing
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Ya couldn't word that much better, the timing on this thing is retarded  My grandfather has a timing gun and my dad is gonna come over sometime this week and help me get this thing into timing since I seem to not be able to do it statically, guess my eyes aren't good enough for Honda, course it would probably help if I had the bike up in the air so I could see the mark a little more straight.
Thanks for clearing that up Shiny
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Got the new headlight switch wired up and mounted, of course after all the time it took to make it fit in the stock control and be able to make it still fit on the handlebars, I found the original spring that I lost that I needed to put the original switch back together.... talk about irony... but I like this switch better anyways and I know I can rely on it and now have an off position for when the bike is just idling and I don't need the light on.
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Re: My 1981 Honda CB750K Project Bike

shinyribs
Administrator
HAHA.I hear you about the irony.Yeah,having an off position would be nice.I wish my bike had that feature. God call
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Re: My 1981 Honda CB750K Project Bike

TOOLS1
Administrator
They had an on/off switch in the right control until 1974. that's when Uncle Sam decided that we were too stupid to turn our headlights on ourselves.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Was real easy to do Shiny, all I did was buy an on-off-on switch from autozone for like $3 or $4, bent the tabs out, soldered the wires up to it and drilled a hole in the top of the old switche's box, taped up the connections and put it all back on the bars, works great.

Hate to say it but Uncle Sam was probably right since there are a lot of idiots on the road that make bikers look bad, hate those guys....
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Got the bike running much better, ended up being that my timing was dead-nuts on, but the black rubbery screw on carb #2, which I'm assuming is the fuel adjustment screw, just needed adjusting while the bike was warmed up, and presto, bike runs good, lol. Feel so stupid, but hey, at least it wasn't anything that cost me money or more labor. Got a video I'm trying to upload using facebook on my phone, stupid facebook wants cell service to do it tho.... so will have a video here shortly. Now I warn you, I hardly ever record anything so the video is probably crappy but you get the idea.
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Re: My 1981 Honda CB750K Project Bike

cdaiscool
Depending on if you have a smartphone, you can also upload it to Youtube directly, and then make it an unlisted video. That way, you can share the video by giving out the link, and only they can see the video. Well, anyone that has the link...
Turbos, Hondas, 4-bangers, what could go wrong?

Fuelly

Shiny: [...] Considering the weather you've had to put up with I'd say you get an Iron Butt award and a Frozen Nipple trophy to go along with it. First time I've ever posted the word nipple... it ends here.
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Sure, now you tell me, lol, I plugged the phone into the computer and am uploading it to youtube now, taking forever as I am downloading huge files at the same time....
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Re: My 1981 Honda CB750K Project Bike

cdaiscool
What can I say, I'm part of the 99% - I'm a day late and dollar short. :D
Turbos, Hondas, 4-bangers, what could go wrong?

Fuelly

Shiny: [...] Considering the weather you've had to put up with I'd say you get an Iron Butt award and a Frozen Nipple trophy to go along with it. First time I've ever posted the word nipple... it ends here.
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Aha, so hear it is, again, dont expect anything special from my filming
<nabble_embed>http://www.youtube.com/watch?v=a8-DloCJaiQ&feature=youtu.be</nabble_embed>
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Ok second try at the embed thing thanks to directions found from Shiny
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Re: My 1981 Honda CB750K Project Bike

shinyribs
Administrator
"eh   it'll smooth out eventually..."

Man,that thing revs FAST! Alot faster than my SOHC. Is mine outta tune or do the DOHC's just rev that much faster?

Either way.Cool video.
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Idk man, all I know is this bitch can rev right up to redline with a twist of the throttle when it's warmed up and running right. I got anxious and drove it up my driveway and back without the front brake on the bike, came back down my driveway and touched the throttle and spun going downhill, easy, very torquey bike.

My dad said my uncle had one and they took the motor off it and put it on a go-kart, and then got rid of it because it was dangerous...

So I currently got the front brake on and it won't unlock, I've bled it out several times and have no idea why it won't let go. It originally locked up when I first got it and we freed it up and cleaned it and it was fine, now it being a pita when all put together. Anybody have any ideas why it not opening now?
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Re: My 1981 Honda CB750K Project Bike

TOOLS1
Administrator
It's probably the master cylinder not letting it release. To test this, when the break locks up crack open the bleeder. If it frees the break, then it is the master cylinder. Often the little holes in the bottom of the reservoir will plug up, and cause this.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: My 1981 Honda CB750K Project Bike

Hellbilly429
Ah, I didn't think about that, there was so much rust in the brake fluid when I tore everything apart, so that makes sense. What should I clean the master cylinder out with?
And did you ever figure out if you had a vacuum leak on that bike of yours?
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Re: My 1981 Honda CB750K Project Bike

TOOLS1
Administrator
I just soak the master cylinders in carb cleaner. I have been pretty busy, and have not had time to mess with the bike. However I did make a gas tank that hangs from the ceiling of the shop to test run bikes with. Now I wont have to have a saw horse holding the tank in my way when I sync carbs.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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