Motorcycle Repair: 1999 1340cc heritage classic, aftermarket pipes, stock ignition

Question
QUESTION: This bike has never run right,It cuts out at high rpm's.What to check?it has a carb.slide kit w/slipon aftermarket pipes.

ANSWER: Do you have the stock ignition, if you do I think it has a rev rpm limit of 6250 rpms. Does it cut out below this rpm.

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QUESTION: it used to run right wide open, but now it cutout at high rpm.sorry I did not have correct info.what else could be the problem?

Answer
You probably have a intake manifold leak at one of your heads. To check for a leak start the bike up let it warm up. Then with bike at an idle spray carb cleaner on the clamps where the intake manifold meets the heads all the way around on front and rear head if the bike rpms slow down or it stalls out you've got a leak. Let me know what you find out and we'll go from there.