1998 Sportster 1800 engine cutting out after running awhile

[mattbraafhart]

I took my sportster out yesterday and was running fine cruising at 5500RPM, then I stopped and started up again at full throttle, one engine tached out at 7K RPM which is normal, but Port engine wouldn't go past 4/5KRPM, then started cutting out intermittently like one cylinder was down. beached it for awhile, went back out, ran full throttle 7KRPM no problem for about 5 miles, then started cutting out again, same engine.

Does this sound like a bad plug or fuel issue? Where should I start looking?

Thanks!

 

[Albysure]

I would check fuel system first....plus r you premixing your gas or still runing with the premix system...if so make sure all that is good and runing correctly. Ctest the cylinders.