Hi. New to this so here it goes. Bought old jotul on craigslist and installed into existing flue. Vent comes of back of stove and immediately increases to a 6" tee. On top of tee there is no rise just a 6" 90 that goes into flue tile. I have about 24" of pipe then traveling horizontally inside of flue tile before hitting the vertical rise of 8x8 chimney. I'm having hard time getting stove to start and when running its smoking heavily. Using only 2x4 and oak from pallets so far,? Should I change tee to a 45? Plz help. Thx.