[Algee]

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???

 

[Algee]

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???

Today...checked the exhaust pipe and y-pipe for cracks...all good, and no signs of any oily exhaust leakage anywhere. Took the heads off and checked the cylinders, all looks really good, no problems with head gaskets.
Next step...maybe I'll change the crank seals. Running out of things to try so might as well. While I'm at it I'll go over the wiring connections really carefully, check the crankcase for any signs of cracks, double-check the new stator and magnet.

 

[Ski Doo King]

I doubt this is the problem.. but maybe check the pistons may be some rust or something got in it???

 

[Old-Not-Obsolete]

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???

I know this thread is kinda old, but I was cruising around looking for information...
Did you check the rubber plugs inside the carbs? If they are in the wrong place, it will do exactly what you're describing. At least that's what mine did. Took me a while and a handful of hair before I found the problem and then I was like, DUH!

Enough gas gets in there to run, sucks it out and then dies. Almost like a vapor lock or bad fuel filter on a car engine.