Vintage and Classic Hondas

80 cb750c wont start

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lolondar
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80 cb750c wont start

lolondar
Fresh fluids fresh gas hoses repaired no holes battery charged. And everythings getting spark etc still won't. Start anyone got any ideas?
FastCletus
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Re: 80 cb750c wont start

FastCletus
Gas on?

Spray staring fluid in Breather box.  Does it catch?

100% sure ALL cylinders are getting spark?

Timing in line?

Just some things I would check
@FastCletus552 aka Jimmy C, buildin' rides out of Napa CA
Current Build 1980 CB 750 F
Finished Build 1975 CB 500T Cafe Racer - SOLD
2002 Ducati 998 Biposto
2005 Rossi #46 Scooter
lolondar
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Re: 80 cb750c wont start

lolondar
Gas is on all cyc getting spark it turns over but never seems to catch.  How do I check the timing used to working on trucks first bike I've had that wasn't brand new off the showroom floor startinh fluid in breather box have to try that friday
FastCletus
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Re: 80 cb750c wont start

FastCletus
Download a manual, and read through on timing.  trust me you will need manual
@FastCletus552 aka Jimmy C, buildin' rides out of Napa CA
Current Build 1980 CB 750 F
Finished Build 1975 CB 500T Cafe Racer - SOLD
2002 Ducati 998 Biposto
2005 Rossi #46 Scooter
TOOLS1
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Re: 80 cb750c wont start

TOOLS1
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In reply to this post by lolondar
Just because you are getting gas to the carbs does not mean gas is getting into the cylinders. Is there gas on the spark plugs?
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)
lolondar
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Re: 80 cb750c wont start

lolondar
On the number 4 there is and a little on 1 damn so 2 and 3 no gas anyone walk me threw how to check the lines short and easy?
Manual
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Re: 80 cb750c wont start

Manual
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lolondar
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Re: 80 cb750c wont start

lolondar
Recleaned carbs second time got a bit more goo added fresh as to carbs let sit cleaned added carb cleaner let dry added touch of gas replaced on bike caught and died now all plugs have gas on them and all have spark still won't catch for more then a second
TOOLS1
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Re: 80 cb750c wont start

TOOLS1
Administrator
Carbs are still dirty. Find Professor See's thread on cleaning the CV 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)
seestheday
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Re: 80 cb750c wont start

seestheday
Ya, you can't properly clean the carbs in an hour.

Even a half asked job requires that you pull every jet and clean with an e string.

Full clean requires splitting the bank and days of soaking.

Search for dohc carb cleaning procedure.
1981 CB750K with 900 cams
90K KM's, rebuilt head, rebuilt carbs, upgraded valve stem seals

My wife's recipe website that I'm trying to help promote: Strawberries for supper. Yes, I am a lucky man.

seestheday
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Re: 80 cb750c wont start

seestheday
Actually, if you really want to do a good job cleaning the carbs, here is the manual.  I'm linking to the other forum because this manually occasionally gets updated and I want others to continue to find it.  This is a fantastic free resource for all of us DOHC guys:  http://www.cb750c.com/modules.php?name=Forums&file=viewtopic&p=157399#157399

1981 CB750K with 900 cams
90K KM's, rebuilt head, rebuilt carbs, upgraded valve stem seals

My wife's recipe website that I'm trying to help promote: Strawberries for supper. Yes, I am a lucky man.

lolondar
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Re: 80 cb750c wont start

lolondar
In reply to this post by lolondar
Hmm well as I expected y'all were right pulled the carb off again and cleaned the jets (used a sewing needle worked awesome btw) put the carbs back on runs now I just have to take it switch the throttle cables again I put em on backwards (facepalm) a job for tomorrow but other then that she sounds louder then my truck and twice as mean
seestheday
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Re: 80 cb750c wont start

seestheday
Errr... I hope it was a really thin sewing needle.  It is easy to make the jets bigger by pushing a piece of steel through a small brass hole.

I wouldn't use anything other than a .10 guitar string to clean my jets.
1981 CB750K with 900 cams
90K KM's, rebuilt head, rebuilt carbs, upgraded valve stem seals

My wife's recipe website that I'm trying to help promote: Strawberries for supper. Yes, I am a lucky man.

lolondar
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Re: 80 cb750c wont start

lolondar
Lol I know that it is a fine embroidery needle things are thinner then e strings (and I happen to have a couple sets) I was also gentle used the neeedle tip to loosen and compressed air to clean :) I'm not a guitar player and I didn't want to drive an hour to the nearest place to buy guitar strings zeeglers in monroe lol
lolondar
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Re: 80 cb750c wont start

lolondar
New problem bike dies when I try to let it idle but revs good
trapper
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Re: 80 cb750c wont start

trapper
Turn your idle up
It ain't a custom till you have customized it yourself.

1981 CB750c (current daily ride and build)
1980 GL500 (Stripped and rebuilding)
1981 CM450 (Stripped and rebuilding)
TOOLS1
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Re: 80 cb750c wont start

TOOLS1
Administrator
In reply to this post by lolondar
If it will idle with the choke on, it's the pilot jets still plugged. If not it could be the air screw settings, or out of sync.
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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