Start Up Issues After Long Time Not Running

Finally got my 1982 GPZ1100 front and rear swap done after 6 years. Surprisingly it started right up but only runs for at most 15 seconds, then shuts down. It sputters and shuts off. It then cranks and doesn't start. During the time not running the engine the cylinders got honed and new rings got installed. The valves were lapped and adjusted. So, I have compression. The fuel is flowing to the injectors and after prolong cranking amy getting backfiring and fuel coming out of the muffler. I don't think the coils are getting hot as it it isn't running long enough...

Is it a vacuum  line leak?  Fuel tank breather blockage?

grab 4 of these from your harbor freight.

www.harborfreight.com/in-line-spark-checker-63590.html

At least you'll be able to eliminate the lack of spark as an issue for about $20.
You'll have to rig it somewhat as the terminal tip won't unscrew. You may be able to wrap the terminal on the tester in electrical tape or vacuum hose to ensure it contacts the terminal in the spark plug boot. 
I just wedge it between the inside of the rubber boot and the outside of the terminal clip. 


 

It sounds as if you're getting too much fuel. It fires briefly, but then eventually you've got too much fuel and it won't ignite anymore. 

The more I ponder it as I work on other home projects, I am thinking it is flooding.  I am going to check the resistance of the air temperature thermometer and make sure the pressure regulator is working correctly.  I have an adjustable one that I was going to install to get rid of stumbling but then opted for the original one. 

I am going to get the inline spark plug and check the spark the next time I am down by the Harbor Freight store.  

I would think that fuel running out of the mufflers is a sign of a stuck open injector or injectors?

Mike

Ok, I will keep that in mind.  I should have known it wouldn't start right up after sitting for 6 years again like it did the last time... 

I am 99% sure that I found the issue. I put a pressure gauge on the fuel return line from the regulator and it was 50 psi which made me think that something wrong was check/pressure relief valve in the tank. When I drained the fuel and pulled that valve it was stuck and frozen closed. I cleaned and douched it with carb cleaner. I also found some rust that I need to address before I put it all back together. 

Any suggestions on how to fix the sending units?  Getting infinity on the ohmmeter...