smoking alot running like crap

[dan87quest]

hey guys i have an 89 zilla. never really got to ride this but now i feel the need to get her going. i bought it about 2 years ago, had a new top end done, clutch, reeds. and the frame sandblasted and painted. my problem is when if i even can get it started it runs like total crap. hard to keep running and smoking alot, to the point of dripping oil out of the header. it's not the mix because i drained the gas and added fresh fuel mixed it to specs. i also tried a carb i got off of e-bay but no change to speak of. the low end is barely there and feels like it takes forever to get any revs. also it sounds like it's popping inside the pipe when running.
please help

[Apher]

Timing key?

[dan87quest]

it was good i changed out the magneto and had the flywheel off. i looked it over good and it's not distorted or anything.

[flotek]

if yo u have good compression(check it !) ...you may have blown a crank seal sucking tranny fluid or possibly a head gasket leak sucking antifreeze

[dan87quest]

compression is very good. i will try to check out the crank seal though

[sblt500r]

mine blew a crank seal. it was a bitch to start. but it ran pretty good. just smoked alot. it does sound like a crank seal or a crack in the crank area case.

have you tested the stator? is it timed right?

[dan87quest]

just pulled the engine. piston cylinder an head all look like new. power valve is crusted up with what looks like burnt oil.
i've been going through the book. where is the crank seal located? do i have to split the cases?

[sblt500r]

crank seal, is probably called a main seal in the book. its the left main seal that could be leaking. its on the clutch side of the crank. or the right side of the engine, behind the crank gears

[dan87quest]

thanks guys. i'll let you know how it comes out

[dan87quest]

fired it up today for the first time in a while. second kick.
i let it idle for 15 mins to break it in. everything seemed ok. the problem started when i tried to take it for a blast. it just has very low power. sometimes it seems like it wants to go but just kindof make noise and goes nowhere. any help would be greatly appreciated