trouble starting and misfireing

[bc750]

Hi I just bought a 77 cb750k about a week ago after charging the battery and putting in fuel it started up fairly easy but kinda putted and backfired, and the carbs leaked.  I took the carbs off and cleaned out the bowls thay werent really that dirty but they did have a small rust looking spot at the bottom of each carb.  i opened the top of the carbs and every thing looked clean but I didnt take any of the insides out.  after putting everything back together the bike ran pretty much the same but no more leaking.  I took it for a ride and i was only able to give it a little throttle or it would just bog out.  also when trying to let it idle it would stall out and then not want to start again for a minute or two.  I changed the plugs and it sounded better but still back fired a little but i was able to open the throttle completly and it had way more power.  After about a 7 mile ride the bike is starting to bog out again when i open the throttle.  Also i belive the preveous owner had used car oil i also changed the oil and filter with motorcycle oil.  The bike still doesnt want to idle and after it stalls out it doesnt want to start for a couple minutes.  Any help is greatly aprecheated

Brandon

[79810k]

Get the Carbs Synced

[blackhawkrider]

also spray cleaner in every jet and opening let sit for a little while the force compressed air through all the openings. It could be clogged jets or any number of sitting related issues with the carbs. A in depth cleaning will at least rule out the possiblility it is dirty carbs. When in there check to make sure all the jets are still stock and all match in all four carbs. If it has mains and secondary mains make sure they are in the right spots. Good luck

[liljohnnie69-2]

Check valve clearances.The backfire and the sluggish running could be due to an exaust valve(s) hanging open.It's easy and if you do it yourself it's free.Before shelling out $$$ for carb work.
 Spec is .002" to .005".Try this,turn off the kill switch and crank the engine.Does it sound like all 4 cylinders are building compression?If they sound O.K. take it for a ride and check it again hot.
 If the base engine isn't right the carbs don't even matter.And check compression too while you've got the tank off a burnt valve will cause what you're describing too.

    Good luck!
   liljohnnie69