Topic: 76 cb550 smokes and dies w/o throttle?

[skinney574]

Hello guys i am taking on my first attempt at a bike restoration. The foundation for this build is a 1976 cb550f and I would like to get i running smoothly before it gets turned into a sweet cafe racer. When i got the bike it wouldnt start, therefore i refreshed the fluids, and cleaned the carbs. Now the bike will start, revs smoothly, but dies once i let off the throttle... In addition I did notice that there is a fair amount of white smoke coming from the oil breather and exhaust. I checked the carb jets and they looked to be okay. What is the next best item to attack in order to correct the no idle, and white smoke issue? Does this thing need new rings? Where do i go from here?

Here are a few items that may help: compression is 85-75 across all four... air box completely off... cleaned points... New battery... adjusted valves... Carbs cleaned...

Thanks in advance for all the help!!!

[KingCustomCycles.com]

Your compressions are low and smoke at the rocker box breather is a clear indication of rings not sealing.  If it is rideable, I would put some miles on it and see if it improves.  A dose of seafoam additive in the oil might also loosen stuck rigs if that is the issue.  The idle problem may be as simple as setting the low speed stop screw or as complicated as intake valve sealing issues. 

[cameron]

pics or it di-

/sigh