69 dt1 250. the carb doesnt seem to back fire but the kick lever does some on starter fluid.
iv tryed 3 carbs - a dt125 to 175 carb, a vintage orginal carb and recently a pwk34 carb.  
i set timing to 3.2 mm btdc with guage and multimeter but seems like a got a timing problem?  thanks for help

Sounds like flywheel key gone, but if it's at 3.2 then got me beat, can't be that.
If the key is in place then set the points at 12thou & see what happens.
Don't worry about measuring btdc for this test. Just see if it runs.
On second thoughts ignore all that & it might be just flooded up in which case drain the bowl from the side main jet then just kick it on open throttle.
Is the plug constantly wet like it has a case full of fuel.
Drop the exhaust & see what comes out.
I'm doubting its damaged a crank seal as pretty robust--but then again--i think the right side it retained by a circlip & stator plate might stop the left escaping without researching--i've never lost one in mine.
She'd start with No Carb if its got fuel in there, but need away to stop it as it clears then revs up.
Did that on my Excelsior & hid around the corner until it stopped haha when 11 years old.
Tell us more--what was going on before this. Parked up for a long time? with fuel turned on etc?.
Oil tank over time can [but shouldn't] gravity feed through the pump & into the case [crankcase that is].
Whatever the outcome just be very sure the flywheel nut is very tight & i hope you have the correct flywheel puller.

im trying to get it started with the exhaust off the bike. it should fire up fine without the muffler right? then put it on once i get running. mainly because my mounting bracket on frame was cut by someone and needs a weld.

wish there was some jedi mind trick where i could just stare at it.

i thought it was my cyclinder compression so i put a used piston and jug done at 70.25mm off of ebay so i dont think its that anymore. iv pulled flywheel. tell you what not to try that some guy on youtube had me try was taking a 68 flywheel and grinding it apart so i could see points and all easy but when put back on 69 flywheel it was different size so total waste. Someone told me flywheels could very. So iv pulled the flywheel a few times and think key is ok. my main thing is if my kick lever is backfiring does that mean i need to retard timing more or advance it. ill try the .012 gap. got just engine and frame and forks and few other parts from a guy local and have got lots of parts off ebay. i been at it for years now. it was on back burner and for sale once when lost interest. i just got some new rubber to put on bike so im pretty bent on getting something going even if i gotta get another engine but cant really afford it. i dont know why but its on hard. got a oil leak too kinda think its the oil drain screw with no gasket but not sure yet. thx

How far off could the wrong key for the flywheel to shaft be?
Keep messing with that timing and related stuff

Are the points at 0.012"?

When you kick it over, does it spark?