New here.. and to the scene...

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New here.. and to the scene...

KNKLHED
Hi, my name is Kerry, I'm 28 yrs old and live in Kissimmee, Florida.. I've been riding for a little over 6 yrs combined.. I got in a real bad moto accident three years ago, but due to ever rising gas prices and the overwhelming urge to own another chopper/ bober I purchased my first CB I've owned a couple Hondas before but this is by far the oldest and kind of oddest.. It's a 1978 CB750A Hondamatic. Here's the pics:
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It has brass knuckle footpegs and a brass knuckle suicide shifter:
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It also has K&N pod filters on the carbs:
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Now I want to explain that I am definitely NEW to the CB scene and want to take in anyone's info and advice on how to ensure this thing stay in daily rider status... It is my only source of transportation right now.. It's an unfinished project bike from someone else, but not much left I would assume before being 100% and starting to tackle personal preferences such as an actual seat! haha.

Things I know it needs immediately:
 -- With the pod filters I was told to up the jets to 120's.. any thoughts on this?
It does have to get warmed up before it lets me kind of pull on the throttle or it will choke out
 -- I need to purchase a front master cylinder rebuild kit for it.. How hard is it to rebuild?
 -- If your sitting on the bike the second carb form your left leaks gas out of the overflow valve regardless of the petcock's position..
I've done some research on this and sounds like it's a stuck float valve needle, but don't know exactly what to do to find out for sure.. or even what to look for if I oull the carbs and start disassembling them..

Of course, as I said before, ANY and ALL help or guidance until I can get my hands on some shop manuals and start learning for myself would be greatly appreciated.. Thank you in advance for your time and patience! Ride safe!








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Re: New here.. and to the scene...

Re-run
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I got your email yesterday but it was late.
Before starting anything, do a the basic tuneup on the bike. Nothing will set right without a good tuneup.

Pull the plugs and remove the valve cover caps. Set the valves according to the manual but add .001 to each measurement. You may get slightly more valve train noise but it will breath a bit better and wear less.
If you still have points, inspect the point faces and use a fine file to smooth them out if needed. Get some points cam grease, HD shops still carry it usually since so many old HDs are still on the road. Lube that points cam. Check your advance mechanism and make sure the springs are still strong and snappy.
I would suggest getting a dwell meter. You can find them used sometimes or get a new one for about $60 at sears. Use it to set the point gap, much better than using feelers IMO. After this, set your static timing and then use a timing gun, about $12 at harbor freight, and set your dynamic timing. I got mine from HF and it works good.

Now, use a multimeter and set it to ohms and check the plug caps. Should read around 5000 ohms. If 0 or bumping against 10000, replace the caps. Inspect the coil wires to make sure everything is clean and there are no cracks in the HT wires to the plugs.

Now comes the sucky part. Remove the carbs and give them a good cleaning. Disassemble them things and remove all the fuel tubes and slides and such. Spray things down and wipe them off. Run Qtips or pipe cleaners through the tubes and other holes. Get all the crud off.
When you remove the jets, the mains just unscrew. The idle jets are pressed in BUT can be removed. Crap a bit of cloth around the jet and grasp with pliers. Twist and pull and after a bit they should pop out. Be careful to not wiggle the jets much or you can crack the seat. You will also pull out the fuel screws BUT twist them in lightly and count the number of turns so you can set them back to the same position after cleaning. ALSO, besides the fuel screw, there is a little oring, washer, and spring to watch out for.
Keeps these parts separated according to carb number.
Use a soft wire such as a thin strand of copper wire to clean the jets holes with. Many people just dip the carbs and then still have trouble. Use the wire carefully and it will clean much better. Then spray with carb cleaner. Make sure to also clean the float needle and seat.
The idea is to clean things enough where you could drink through them, gas taste not withstanding.
Now, check your carb manifold boots(the ones between carbs and engine) for cracks. If you have deep cracks, replace them. They are hard to find though but I think david silver spares has them.
Get it all put together and mounted back up.
Now before hooking up the gas line, you should have made sure the petcock actually turns off the fuel. If not, then that needs work or replacement.

This will get you a good base to start from.


Jetting is tricky with pods. At least you have the k&n pods which are a much better quality then the cheap chinese ones. Have you started the bike at all and run it some? First thing would be to determine your air fuel mix. So, clean the plugs or get new plugs. Start and warm the bike up and let it sit and idle for a while with no choke. You can rev some but stay below 4000. After a 10 minutes of that or so, kill the engine and pull the plugs and see what the insulators look like. You look to have the stock carbs so your plugs should be a very light tannish color. If they are white, then try turning the fuel screws out a half turn to start and try again.
Now, if you can, get the bike on the road and run the gears a bit while keeping the rpms above 5000. So you will want a highway for this. Oh wait, you have the A bike so only low and hi.
Run it up to 50 in low and shift and get to about 70-75 and then hit the kill switch. I would tell you to pull the clutch but you don't have 1 I don't think. so kill it and coast to a stop in hi. If you can, let it cool a bit as it will be hot, or have mechanics gloves. Pull the plugs again and see what the insulator looks like. Should still be a light tan. If the insulators are white, then move up a size in jets. I can't remember what the A has for mains but if you had 110, go to 115 to start. Continue on till you have a good mix on both ends.
Now, use a vacuum gauge to sync the carbs. Borrow one if you can as they are about $60 starting.
Your #2 carb is your base carb and cant be adjusted, you adjust the rest of them to get as close as possible to #2. Once you have them synced, hook up that handy dwell meter as it most likely has a nice accurate tach. Use this tach to fine tune your idle mix. Get the bike to running temp and start on #1. Set rpm to about 1200 and put a fan on the engine for cooling.
Tune the fuel screw till you hit the highest rpm and then back it off a bit. Set rpm back to 1200 using the idle knob and repeat for each carb.
Oh, if you do not know the age of the oil, change it. I suggest at least rotella t 15-40 if you have a budget. If not, I use rotella 5-40 synthetic. It works awesome but keep in mind, if your engine seals are bad, the detergents in the synthetic may clean away the sludge and cause leaks. So if in doubt, do the 15-40 or at least a quality 10-40.
 i know this sounds like a lot of work and I will not lie. It IS a lot of work. But you will not need to do it more than once avery couple of years, aside from points and oil that is. It will take you a day or so of fairly constant work.  When you are done though, you should have a good running bike. I will say though that pods can be difficult to tune and are weak to rain and strong cross breezes.
The ride IS the adventure. The destination is just to get gas!
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Re: New here.. and to the scene...

TOOLS1
Administrator
In reply to this post by KNKLHED
Welcome to the forum. I really like your bike. the As are my favorite. I have two myself. There cool factor today is off the scale. I want a brass knuckle shifter too.
re-run pretty much has you covered, but did not get to your master cylinder. It is easy to rebuild. Here is a link to a very good video on rebuilding them. http://www.youtube.com/watch?v=2W24asyNujs Also I recommend you get the special snap ring pliers. I got mine, for $10.00 from vintagecb750.com they are well wort the price. Also these bikes are cold blooded. They do not like any throttle until they get warmed up. Iridium spark plugs are a big help. They are pricey, but worth every penny.
Another thing on the carbs. They are notorious, for the accelerator pump ball valves being stuck. Be sure to check them.
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: New here.. and to the scene...

KNKLHED
Thanks so much to the both of you for your help and guidance! As I said before! haha! I'm completely new to this so I may have to turn this over to a professional for the first time until I can get some manuals and start reading.. After watching the video I'm positive I'll have front brakes by the weekend though! haha
I definitely wish my Uncle lived here still so I could have him look over my shoulder through this.. I understand it's a big over taking and I hope it gets better with time..

After running the bike around the neighborhood a few times and parking it in the garage it wreaks of gasoline.. no signs of leaks anywhere and double checked the petcock for off position.. any thoughts? I'm assuming maybe the petcock doesnt stop the fuel flow as re-run previously mentioned..
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Re: New here.. and to the scene...

Re-run
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Well it sure sounds like it is not running rich if it stinks like that but keep in mind, these old bikes like to stink anyways. Part of their charm!

This link is a large manual and I think it includes some info for the A.
http://creativeconceptcomputers.com/CB750/sohc6978large

Check it out, some of it will still pertain to other aspects of the bike.

The petcock on my 78K has a 3 position switch. On points down. Off is level. reserve points up.
The ride IS the adventure. The destination is just to get gas!
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Re: New here.. and to the scene...

KNKLHED
Yea!! My petcock is a three-position apparatous as well.. but it goes as follows: Level is off, straight down is on and reserve is 45 deg past that.. I think i should just switch to one that is on-off...
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Re: New here.. and to the scene...

Re-run
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Maybe not a bad idea. Just keep in mind that you will have no reserve position so when you are out, you are out!
The ride IS the adventure. The destination is just to get gas!
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Re: New here.. and to the scene...

TOOLS1
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In reply to this post by KNKLHED
Oh don't do that. You will be cursing yourself. especially while walking in the 100+ degree heat there in FL..
Since you have a sporty tank. Finding a quality replacement petcock should not be a problem.
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: New here.. and to the scene...

KNKLHED
Yea.. I was looking at it today and I think it's pretty easy to swap out.. I'll just find one for the tank and go from there.. I'd like to see if I can find one that actually 'clicks' into place.. so I know for sure when its in whatever position I'm trying to get it into.
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Re: New here.. and to the scene...

KNKLHED
So the bikes registerd as of today and I dropped it off to Motorcycle Clinic here in Kissimmee.. Boy, it sure was hard trying to find a local shop that worked on vintage bikes! Got one though! and he's gonna call me tomorrow with a damage report and I'll go from there!
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Re: New here.. and to the scene...

TOOLS1
Administrator
Just be sure they don't Mickey Mouse it
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: New here.. and to the scene...

KNKLHED
Haha.. what do you mean mickey mouse it!?!

By the way... anyone know where I can buy pairs of bar end mirrors for 1" O.D. bars? I tried googling them but nothing... :-/
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Re: New here.. and to the scene...

Re-run
Administrator
I think he means to check the shops work to make sure they did it right.

As for bar end mirrors, the difficulty finding them is caused by the fact that it is mainly brit and jap bikes that are cafed and they use 7/8 bars.  But a google search pulls up a number of options. I googled "1 inch bar end mirror", no quotes.
The ride IS the adventure. The destination is just to get gas!
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Re: New here.. and to the scene...

KNKLHED
OMG!?! Guy at the clinic told me it's gonna be 900-1000$ to just flush the tank, rebuild?sync carbs and rebuild the front master cyclinder!! Does that sound right at all!?! That is outrageous!! He also told me the guy that built the bike did the rear brake setup wrong and the brake is binding so it would have to be rebuilt as well!! When I test rode the bike this wasnt evident at all! I ran and stopped just fine!! Wth!?!

Thanks Re-run.. I'll re-search for them again and see what I can find!
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Re: New here.. and to the scene...

TOOLS1
Administrator
It was reference to being, so close to Disney World
Anyway. I would be happy to do all that work, for half of what they are charging. The things you need done are very easy. You would probably spend about $100 on parts, $50 on a set of gauges, and $15 on the snap ring pliers, for the master cylinder.
If you want to try to tackle all, or some of these items your self we will be happy to talk you through them.
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: New here.. and to the scene...

KNKLHED
Yea.. I been pricing things on the net and was figuring $120 for the carb kits and master cylinder kit.. I want to give it to a shop for now and luckily found a friend from the past thats owns his own speed shop and works on bikes and drag vehicles.. said he'd do it on the side and have it done in 3-4 days for 300$ I'd rather tinker with the bike when I know what i'm doing isnt an urgent issue to get it back on the road..
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Re: New here.. and to the scene...

cityslicker
I dig this bike.. the seat looks hella uncomfy, but damn thats a sweet ride.
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Re: New here.. and to the scene...

Piute
In reply to this post by KNKLHED
Hello,
  Nice looking start you have there but,when some
-one leaves you to finish ,theres lots to run into that is not noticable,to the untrained eye like myself for the 750s ,
  The guys on this forum are great group and have read and reading about builds going on now,I believe
 we all like to save are $,Not real sure what reputation of mechanic you seen,I'd do as much as possible yourself (and a friend)brakes and cleaning your carbs should be easy enough ,like they said there/we are here to help out and keep you going on your build,
  I haven't even road mine yet,but not to worried snow be here(mo.) few months and will have a few bad weather months to get in tuned to perfection and color changes and such.
  You have a good bike (750s) I'm not one to sway about automatics,But if "The Man" TOOLS says there cool thats good by me.>>>Piute<<<N>>>Jodose<<<
                            1977 CB750 F2 Super Sport
<LET THOSE WHO RIDE DECIDE><RIDE TO LIVE-LIVE FOR JESUS> 
Native American from central Cal,  Kickstand UP in S.W.Missouri,
                                       
 
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Re: New here.. and to the scene...

shinyribs
Administrator
Welcome to the forum!Oh man!That thing is perfect!! Love the knuckles.Very cool ride.
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Re: New here.. and to the scene...

TOOLS1
Administrator
Seeing this thread brought up again, has me jonesing, for a hardtail.
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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