im breaking in a GRP .28 motor, heres how its set up

#6 plug
three copper shims, 1 alum. shim ( to take stress off con rod)
o'donell 20%
msr 1005 pipe.

4turns out hsn, 3.5 turns out lsn.

i have it in my MBX5T, and i cant get it to start to save my life. it just turns over with no signs of smoke coming out the exhaust. i did notice air bubbles moving back and forth in the fuel line. is that bad? i checked the glow plug and it working fine.. any help at all is appreciated.

this is just getting real irritating