knavin
CB750 New member
Hey everyone, this is my first post. I picked up a 1978 a couple weeks ago and started tinkering with it. I've had lots of bikes and work as a mechanic for a living, but I know these bikes are their own animal.
So, the story. An older guy owned it and took really good care of it (evident from the condition). He died and the person that bought his house found it in the barn and sold it to me. The old plate says that it was last registered in 2003!!! Everything appears stock, including the 4-2 exhaust.
I took the carbs off and cleaned them up. Cheaping out until I knew that it actually ran (separated them, jets out, no rebuild kit,just new vacuum hoses and cleaned and reinstalled everything else). I dumped out the cruddy gas, changed the air filter, new battery, and made sure it at least had some sort of oil in it. Fired right up after a few cranks and messing with the choke... and NO LEAKS!!!
Now for my quesrions/concerns...
it idles high (2500ish) at full choke and tends to sneek up to the 3-4k range if I don't play with the choke.
I know they are cold blooded, but it never seems to want to idle nicely. It will run shakily at 1000 off choke after a minute.
It will die if given quick throttle, but will rev with VERY slow input, but then hang on closed throttle.
The #3 and #4 cylinders seem to be getting MUCH hotter than the other side based on touch and the SMOKE rolling off of that side of the bike! Not fire smoke, but steam off of a hot cup of coffee on a cold day. I didn't spill anything on that side and they are noticebly hotter to the touch.
So... I know I need some help on what to do next as far as dialing in the carbs. I was also wondering if anyone has experience with one side running hotter than the other. I know its a alot to read, but I'm trying to paint the picture accurately. Thanks
So, the story. An older guy owned it and took really good care of it (evident from the condition). He died and the person that bought his house found it in the barn and sold it to me. The old plate says that it was last registered in 2003!!! Everything appears stock, including the 4-2 exhaust.
I took the carbs off and cleaned them up. Cheaping out until I knew that it actually ran (separated them, jets out, no rebuild kit,just new vacuum hoses and cleaned and reinstalled everything else). I dumped out the cruddy gas, changed the air filter, new battery, and made sure it at least had some sort of oil in it. Fired right up after a few cranks and messing with the choke... and NO LEAKS!!!
Now for my quesrions/concerns...
it idles high (2500ish) at full choke and tends to sneek up to the 3-4k range if I don't play with the choke.
I know they are cold blooded, but it never seems to want to idle nicely. It will run shakily at 1000 off choke after a minute.
It will die if given quick throttle, but will rev with VERY slow input, but then hang on closed throttle.
The #3 and #4 cylinders seem to be getting MUCH hotter than the other side based on touch and the SMOKE rolling off of that side of the bike! Not fire smoke, but steam off of a hot cup of coffee on a cold day. I didn't spill anything on that side and they are noticebly hotter to the touch.
So... I know I need some help on what to do next as far as dialing in the carbs. I was also wondering if anyone has experience with one side running hotter than the other. I know its a alot to read, but I'm trying to paint the picture accurately. Thanks
