I'm in the process of rebuilding my '88 Phazer. It had sat in the barn for several years. Seems it still has the same problem that existed before getting parked in the barn. It starts perfect, runs like brand new, but after about 10 minutes of running it will start to die. It will usually run at idle or low speed long enough to get home. Let it cool down for a long time and then repeat all over again. I've done quite a bit to troubleshoot. Replaced virtually all the electrical with new or known good parts, including stator, ignition coil, plug wires, plugs, CDI. Cleaned carbs. Checked fuel vent and filter. Bypassed kill switch, TORS, key switch. Replaced fuel lines, vavuum line. Replaced fuel pump. Checked head bolt torques. I'm running out of things to check. I really doubt it is an engine problem like crank seals, top end, etc. because it starts perfectly 1st pull and runs like brand new for the 1st 10 minutes. Any suggestions???