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Hey grumpy. Thank you for the offer. My cam cap has two letters on it, an "A" and an "E". It comes from the forward, rightmost corner of the cams. I will add a picture of it below. Secondly, I got my new nozzle in today, but I was concerned to see that it doesn't look just like my old one. Is it okay to use? I have a picture of them side by side below, the old nozzle being on the left. Thanks for your help.
 
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Administrator
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If it is within an 1/8 inch of the top, it can have a nut welded to it! The welding will NOT hurt the aluminum cap. You will not be getting it that hot, and the molten steel will not adhere to, or melt the aluminum. I use an aluminum block as a backer when welding thin sheet metal just for that reason. It keeps the weld from blowing holes. If this guy is scared to do it, send it to me. I'll do it. That is if it is not broken off deeper then an 1/8 inch.
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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I will measure the depth of it, but it may be just about that deep. Out of curiosity though, how would you go about doing that, precisely? I don't know much about welding, but if you explain it, I may be able to forward that method along to the welder and we can see what we can come up with. (Not that I doubt your expertise. I just already made an appointment.)
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Bad news. The bolt is recessed about 1/5 of an inch.
On Sep 27, 2013 11:19 PM, "TOOLS1 [via Honda CB750'S]" < [hidden email]> wrote:
If it is within an 1/8 inch of the top, it can have a nut welded to it! The welding will NOT hurt the aluminum cap. You will not be getting it that hot, and the molten steel will not adhere to, or melt the aluminum. I use an aluminum block as a backer when welding thin sheet metal just for that reason. It keeps the weld from blowing holes. If this guy is scared to do it, send it to me. I'll do it. That is if it is not broken off deeper then an 1/8 inch.
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
1976 CB 750-A X 2
1977 CB 750-A X 2
1977 CB 750-K X 2
1976 CB 750 F
1981 CB 750
1995 KZ 1000 P-14
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
To unsubscribe from '81 CB750F trying to get it road ready., click here.
NAML
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Administrator
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I would take a 5/16 nut, and place it over the broken bolt, Then weld it to the broken bolt through the hole in the nut. Then just take a wrench and turn it out while it is still hot. I have done this hundreds of times. Never had it fail to work.
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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Administrator
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I've seen the welder thing work.
Tell that guy to get a 3/16 6011 rod, turn the heat up,
come directly into the hole and push that rod in slowly till
the spanking stops.
The steel will not mix with the aluminum.
Get off the rod as soon as the sparking stops,
wait a minute or 2 for everything to cool.
Bend the welding rod 90 degrees maybe 2 or 3 inches from the work.
Slowly kinda tap the bolt out, back and forth,
hopefully the steel weld will be stronger than the little bit of aluminum
that getts messed up at the top of the hole.
Good luck guy, you're in a hellova mess.
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Thanks for the tip. I will certainly mention it to the gentleman I meet with. For the time being, I would like to put my carbs back together, but I am still a little apprehensive about the nozzle that I posted up above. Does anyone know if it would be okay for me to use that one, or should I bother grumpy to see if he can ship the spare he mentioned to me?
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Administrator
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Thats what is called an emulsifier tube. It helps to break up the liquid gasoline into smaller ''pieces'' so that it can atomize into the airstream better. Since those two don't watch you could possibly run into an issue where one cylinder fuels differently than the other. It probably won't be a major difference,but if I had a matching part available to me I would go that route.
And good on you for jumping head first into this thing! That cam cap issue you have is pretty bad, after you get that sorted (and I'm sure you will) everything else will be downhill from there. You really got your feet wet on this one.  Congrats and good luck!
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Good news gang. I finally have that broken bolt fixed. They had to put the darn thing on a lathe to get it bored out correctly, since I already started that off center hole on it. In the end though, they bored it out and installed the helicoil I brought them for 80 bucks. So that, plus the coil itself makes this a $100 repair. So, I think I have learned to be much more cautious when torquing bolts, I can tell you that.
On that note, I realize now that the 9-12 ft*lbs rating that I THOUGHT was for the bolts holding down the cam cover, was actually the rating for the two bolts holding down each cam cap bearing. That COULD account for my sheared bolt. So, my question is, to what torque should I tighten all of the bolts atop my cam cover? I currently have them turned as tightly as I can with my hand, holding the wrench bit in my hand with a dry rag. The guy at the shop was talking inch pounds, so I don't trust my torque wrench that low, obviously.
So, now I am looking at the carb. In my impatience, I would like to go ahead and use the nozzle I have now. I don't need this bike to win any drag races, of course. Would I have to adjust anything to compensate for these new hole positions though? Also, regardless of this new nozzle, now that I have taken the bank off, and am now reinstalling it, do I need to do any tuning or syncing? I believe that they did a good job with all of that at the shop, and I did not take the bank apart or adjust any screws, aside from the jet and nozzle, of course. If you guys can weigh in, then I will happily be putting things together tomorrow!
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Administrator
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Glad to hear you got that cap fixed!
If all you did was a basic disassembly of the carbs your synch should still be fine. Reusing that nozzle isn't the end of the world. It might be a good idea to check that corresponding spark plug after your first ride just to verify that it isn't causing that cylinder to run too lean. It probably won't,but you'll never know unless you check.
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How would I determine the leanness/richness of the mixture by checking the plug?
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This post was updated on .
 Quote: That COULD account for my sheared bolt. <quote.That! does account for the sheared bolt! These bolts have a built-in stop on them, and are screwed in until that stop bottoms out. At that point, the vc gasket is squeezed down to effect sealing...that is how it seals. If you attempt to torque those bolts, they aren't hardened and shear. Period....
I agree, that if you did not split the bank that your previous sync is still intact, but is easy to check before installing...(bench sync) If you go to http://www.cb750c.com/ you will find a most excellent carburetor cleaning/rebuilding manual written buy Sean MacGregor of MacGregor's carb repair service. Manual is found at this link... www.cb750c.com/publicdocs/SeanG/Honda_Carb_Manual_revD.pdf You will need to register to view it. Tons of info on 1979-83 dohc cb 4's ...Bench syncing starts on page 36. check it out
<nabble_img src="PA030004.jpg" border="0"/> 
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Sad news guys. I put it all back together, and that cylinder is still cold, just like before. I was quite upset to see that. What else could be wrong?
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This post was updated on .
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The author has deleted this message.
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Administrator
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If you have compression on that bad cylinder, and spark, it's got to be that carb not letting fuel
into the motor.
Took me 4 times cleaning them when I first got my bike. 
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So, can you give me a checklist of things to look for? Admittedly, after finding the bad nozzle, I did not look too closely at other things. Just look at all of the nozzles, and make sure they are clear?
Additionally, I took the bike for a ride today. I confirmed that I still have my lack of power. However, replacing that nozzle may have solved my inability to rev higher than 7k rpm. I got up to at least 8, but I lacked space and power to push it any higher. When I heard the power popping off and on, I almost thought I heard the flapping of a valve. Could my problem be related to my air cut off valve? I just got new, non-oem ones on all of the carbs.
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No, the air cuts will have nothing to do with that. New plugs??? New plug wires? Look into the coil that plug wire goes to, making sure the little pointy thing is intact and not all corroded. I have seen it completely corroded away! Have you checked the compression on that cylinder? You could have a burnt valve causing you power loss...
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I have checked the compression in that one. It was good, and close to the others. I think it read 142 psi. I will look into the coils shortly.
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Alright, I have some new info. I think my problem is electrical. I ordered a spark tester this week, and tried it out today. The good news is, as I confirmed visually, the plug seems to be getting a spark. However, as I was testing this, I found that, by removing the boot from the plug (This is all on my #1 cylinder, the cold one), at idle, my engine seemed to sound no differently. It still has this kind of stuttering, hiccuping sound. So, that should mean I am getting no ignition, right?
That said, I checked the port where the wire leads into the coil, and it seems to be clear of corrosion and other nastiness. I cleaned it out with a cotton swap, anyway. It did not appear to make a difference. So, I guess, alternatively, the problem could still be in my carbs and my mixture is so bad that I am getting no ignition at all at idle, so the spark would make no difference. What do you think?
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Administrator
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you swapped the plugs around, and they changed color?
maybe swap the leanest into the richest and see how they look after a chop or two?
i still think it's a carb clogged a bit, or an air leak sucking that one cylinder lean.
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