F650ST purchase recently;

I just bought my "University of AZ" daughter a F650ST '97 model and its a fine bike, as I had a '99 F650, which I loved. I am a life member of the Chaingang but forgot how to get back in over there! I rode down to AZ a while back to take a look at what I bought for her and to get her started on her lifes journey as a rider of a fine mark like the F650ST. Jessica has a fine start, with MSF course work all complete and her fresh AZ motorcycle license and the bike of choice for her. The bike is her early graduation present and her tough work there as an inspiring young Aerospace Engineer. I am proud of her.
QUESTION! The bike has a clicking noise coming from somewhere around the motor at cruising speeds, around 40-45mph, off the throttle cruising along, easy like? Seems I recall with my F650 Funduro model, the emmisions pipe along the right side of the motor, coming from the airbox to the header pipe was an issue? Am I right in my memory of this? Plugging these was something many of us did back then and is this what the noise may be coming from. The bike runs just fine with, no issues otherwise and with 25K miles on its odometer. My guess was the emmision pipe made the clicking sounds as gases made the noise, exploding in there! Wrong? I do not know, but I do remember plugging mine in '99, at the airbox side of the pipe, for what reason, I do not remember. ONLY other issue I've read about is maybe the camchain tensioner has a piston arrangement, that has become stuck on some F650's? Unknown to me? I made a good purchase in this F650ST, as it is very clean and a very good fit for my oldest daughter and she loves it. My BMW passenger for so many years as a young girl behind Dad, touring all over the USA. We sure have stories! Now, she begins her own BMW saga in fine fashion, I feel. Please help me with this click noise we've discovered on the ST. Randy13233 and Jessica, also a young new 'moa member.

How many miles? If the F sat for a long time, a possiblility is the cam chain tensioner is frozen. Also, cruising "easy like" you want to make sure you're 4000< rpm. Otherwise the compression release could be "releasing". Which makes a clicking sound. Otherwise, a valve check should be in order. (Which should answer the tensioner question as it's removed to check the valves.)

Thanks;

The bike has been BMW serviced within the past year and at 25K miles, it is a fairly low mileage one. The compression release is another thing I had forgotten! Yes, the rpm's have to be kept rather higher on the F bikes and I have been riding my R100 a lot lately, which is another animal with low rpm performance. The ST is a fine ride and I am sure we will get it figured out for a long future of riding pleasure. Randy13233.