Bam bam is right, it's why I waited till the end of my warranty before modifying in any way. Essentially it is as follows
1) you purchase a new car and are provided with a warranty on the car in the state it left the factory
2) you take it to rons autos who sprinkle it with fairy dust and increase the horses and torques
3) your new vehicle develops a problem
4) you take vehicle in expecting someone else to pay to repair it and haven't told them about Ron and his fairy dust
5) you are committing Fraud
6) you would not be committing fraud if you came clean
7) you would not have told them as I imagine you were expecting a " on your bike son" from the warranty company and didn't want to stick your hands in your pockets yourself

it isn't that complicated to understand why not disclosing pertinent informationis fraudulent in this context. All in my humble opinion of course
She may be big and heavy but its whats on the inside that counts.....