Hey Guys I'm new to Harleys and the forum. I just bought my first Harley a 2003 Road King. When I get on the throttle and say it in fifth gear running 40 mph there is a rattling sound and I can't figure out what it could be. Any ideas. Remember I'm new to Harley so please be specific.

Thanks, Jason

 

Pirates55,

If you are in fifth gear at 40mph, you would be rattling! Because you are lugging the engine. At 40mph, you should be in the 3rd or 4th gear, not 5th gear. You need to make sure you keep your engine RPM above 2000rpm in all gears. Your engine is a rubber mounted, and the only way to smooth out the engine is to be at or above 2000rpm.

 

Yup, I think you are lugging the engine. The "rattling" you are hearing is probably the primary chain slapping around or the valve train. Keep the RPM up that big twin can handle it. I've had mine to 70 in 4th.[8D]

 

The only time you'd be in 5th at 40 mph is going down hill or running really easy along a flat road. That means holding back on the throttle so that it barely pulls. If you give a lot of throttle to it at 40 you're really bogging the engine down at low rpms and putting it under a lot of stress. Most of the time don't shift to 5th until you're at about 55.