My 88 Magna cuts out when I run at around 4.5-5k RPM at extended periods, which is just above 130km/h on the highway. If anyone has had a similar issue and found the solution, I hope you can help me. I suspect that it´s either the alternator overheating, or dirty carbs. The only other possibility I can think of, is an electrical error that doesn´t supple the sparks at high RPM´s...