81 CB750F Jet Question

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81 CB750F Jet Question

GTXS1100
Hi New to this site. I am working on my buddys 750 supper sport and was wanting to know what jet sizes that people have had successe using. He has 4 to 1 exhaust and pod filters. I wanted to order new jets for him but wanted to know what sizes to get. Pilots and mains pls. Thank you
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

LukeM
Administrator
I'm away from my Haynes manual until this weekend.  The information you seek _may_ be in the FSM which you'll find on the home page of our forum.  Feel free to download it (it's FREE!) and see if it's in there.

Good luck, and keep us in the loop.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
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Re: 81 CB750F Jet Question

GTXS1100
Im not finding the FSM whats it listed under? Is there a link for it?
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

LukeM
Administrator
Here's the link to the location for the Factory Service Manuals (FSM) for several of the bikes discussed on this forum.

Hope this helps.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
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Re: 81 CB750F Jet Question

TOOLS1
Administrator
In reply to this post by GTXS1100
What carbs does it have? The 75-76 used round tops, and the 77-78 used keyhole's.
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: 81 CB750F Jet Question

GTXS1100
Not sure what you mean by Keyholes. The top of the carbs are round not sure what size i would assume they are stock i dont know if they came out with more than one set.
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

GTXS1100
Oh and thanks for the link lukem that will be a big help when we realy get tore in to her.
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

Hellbilly429
If it's an '81 than it's the CV Keihin carbs that are not pod friendly according to most because they are vacuum driven and don't like to operate properly without the vacuum caused by the stock air-box. There was one guy on here that said he got his to work, I can't remember his name but he has the leaf-spring bobber on here....
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Re: 81 CB750F Jet Question

LukeM
Administrator
In reply to this post by GTXS1100
You're welcome. We've been kicking around the idea of a "hello email" pointing out stuff like where the manuals are, where to look for stuff on the site, some etiquette for postings, etc.  Do you think that would have helped in this instance?

Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
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Re: 81 CB750F Jet Question

GTXS1100
In reply to this post by Hellbilly429
Ok i can leave the stock box on i just like pod filters cus they make it way easier to pull off the carbs and put back on. I have a set on my XS11. I still would like to know what jet sizes that people have in there bikes. What combination works for them. Also i was wondering if that 81 SS came out with 4 to 1 exhaust stock from the factory. Ive looked at a lot of pics on like and quite a few have the same exhaust my buddys does. starting to think it came that way. Any thoughts? Well if it is stock then the only mod we have using the stock box is a k&n air filter, and maybe removeing the baffels out of the muffler.
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

GTXS1100
In reply to this post by LukeM
Lukem i think that would be very helpful. Im still not sure what your concidering the home page. Also what is the website name? The only way i can find this sight is to google it CB750 Forum.
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

LukeM
Administrator
Try this:

http://honda-cb750-s.456789.n3.nabble.com/NEW-Repair-manuals-April-26-2011-Updated-td685918.html

I guess I was being a bit cute by hiding the link in the link.  Sorry about that.

Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
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Re: 81 CB750F Jet Question

GTXS1100
Haha nevermind i have found it now! Right under my nose!
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

GTXS1100
Any recomendations on jet sizes you think that the stock 102 main and 68 pilots will be enough for he open 4 to 1 with no baffel and the stock air box with the K&N air filter?
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

GTXS1100
I went ahead and bumped the mains up to 105s and left the pilots for now going to see how thing run. got to yank the carbs off again to put in the new jets. how hard is this set of carbs to sync?
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

TOOLS1
Administrator
I don't think they are very hard. Now Kawasaki carbs are hard.
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: 81 CB750F Jet Question

Hellbilly429
In reply to this post by GTXS1100
Sorry I couldn't get back to you sooner, the guy had 120 mains but wasn't sure about the pilots. I am thinking the stock air-box will reduce the need for that big of a main so try the 105's and see how that goes. I'm not sure how much more flow the K&N airfilter in the stock airbox will provide and if it will throw off the vacuum too much, let me know how that works out for you tho cause I wouldn't mind trying it on my '81...
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Re: 81 CB750F Jet Question

GTXS1100
120s are what i have in my xs11 with open headers and k&n pods. That seem large for this bike. My 11 had 110 stock and the cb750 came out with 102 stock seems like a big jump to me. that is just my opinion. But hell jets are cheap ill give it a shot.  
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F
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Re: 81 CB750F Jet Question

Hellbilly429
Right, I know that those are way too big for your friend's setup, this guy has the '81 CB750 leafspring bobber with drag pipes and 4 pods, says that's what he's running to get his setup working and says the pods don't bother his stock CV carbs, but everyone else's testimonies with these CV carbs makes me leery about putting pods on since I just need a working bike and function is more important than looks to me right now....
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Re: 81 CB750F Jet Question

GTXS1100
Well with the baffels out and pods it may be about right i thought i might run 115 and see how it goes
1981 CB750F SS
1980 XS1100G
1982 XJ750
2006 GSX600F