Apparently this bike has sat for a while, so it will definitely need the carbs cleaned.But beyond that, it has low compression, smokes white, and has low power.l do not think these are carb related, l was thinking maybe...blown head gasket or ring?Does anyone know for sure?
How much does this cost to fix, approximately?
Also, the rest of the bike is in really good condition, about 20k miles, it is a 750.KBB is (low) 1000 and (high)1500...what is this bike worth (about) in this condition?
thanks

it fooooked

That is symptomatic of a blown head gasket. Your white smoke is steam.

Needs engine work.Sounds like a blown head gasket with the white smoke and possible rings may be stuck in ring land or groove.

If the smoke is blue, it is oil. It could be rings or valve stem seals. If the former, they may loosen up with use, but the latter wo not get any better. If valve stem seals, they tend to smoke more on start-up & then clear up.

If it is white, then it is coolant & chances r there is a head gasket leaking. It is hard to describe, but antifreeze has a distinctive odor when burned. Check the crankcase to see if the oil is clean. If it is milky or coolant comes out when u remove the drain plug, then DON'T run it anymore because antifreeze will glue an engine up & u will never be able to fix it.

If u think it is a head gasket & the exhaust has a funny smell, drain the coolant, replace with straight water & see if the odor changes. Remember that there may be coolant condensed inside the mufflers, so the odor change may not be immediate. If the exhaust now smells normal, then it is most likely a head gasket & replacement is about the only fix.