Help!!? 1982 honda cb750 won't start!!

[stvnbroker]

Im eighteen and I bought my first motorcycle at the beginning of this past summer. Its a 82 honda cb750 custom. I know im a rookie so any help would be greatly appreciated. This spring it was hard starting so I decided to completely overhaul the carbs. They are perfectly clean, synced and balanced. It started alot better but still took a few tries and minutes to get running in the morning. I noticed If I gave the throttle like 10 twist before I hit the starter it came to life alot faster. the warmer it got outside the easier it was to start too.  Midway through the summer I made the huge mistake of not keeping track of my next oil change. One day I noticed the bike was getting really hot and wouldn't get over 60mph. I drove it home and found the oil was really low and over due for a change. I changed it and thought it was no big deal because my bike still started/ran just the same. It did start to leak a small amount of gas from the right side of the engine head cover though. As it been getting colder oustide its been harder and harder to start. and the last few weeks its been around 40 to 50 degrees outside. Ive been draining the battery and then recharging it or connecting it to a charger to start it. It takes about 30 minutes to get it going. I have no Idea what to try!  Ive been told I should take out the vaccum operated petcock. but It seems like the problem is bigger than that. Help??

[OTTODOCTOR]

First thing to do is figure out what you DON'T have . It takes four things to make an engine run . -- 1 - compression --- 2 - fuel --- 3 - air . --- 4 - ignition . Always start with the basics , and hope you don't have bigger problems . -- If you can get more info. , it makes it alot easier to help you figure it out . -- Otto

[sockeye]

I'm a bit of a neophyte myself, but have picked up a thing or two by trial and error.  This vintage of bike has had problems with cold conditions and it seems that anytime temps dip below 60 degrees they show hesitation to start and warm up.  This may be due to the persnickity jetting solution for EPA regulations in the early eighties Honda.  I'd say it takes about a mile and a half before my 1980 CB750F starts to run smoothly in cold weather - It's just the nature of the beast.
Also, I note that you had your carbs overhauled, probably by a professional on a bench.  My experience was that by turning the fuel mixture adjustment a schoach richer than what the manual calls for smoothed things out nicely.  There is a formal process for getting this just right, but you could experiment/diagnose by tweaking it a little richer - and make sure that you document where the mixture was when you started so you can get back to factory specs. I haven't noted evidence of unspent fuel.
Another problem I've run into is getting a good fuel supply to the carbs.  You may have debris in you in-line fuel filter or debris at the bottom of your tank.  Of course you want to get your tank clean, but in the meantime, by making sure the filter is clear and that you have a substantial height of fuel and that your pet cock is set on non-reserve (takes fuel above bottom of tank) you might get better results which would be diagnostic for fuel flow problems.  Any 1982 tank would predictably have a debris issue unless it had been cleaned and coated recently.
Then again - it could be any number of other things as previous replier stated.  These are just some easier things to check.  You've got to believe that it's worth the trouble, because once you get on the road, you'll be convinced it was!