Popping

[happy wanderer]

My son has a k1200rs that will do over 140. And my r1150r would indicate 135. Also if I wanted new injectors, what flow do I want? There are several available.

The injectors you want are not normally ordered by flow rate but rather a BMW part number.
From the MaxBMW online Fiche:
13 71 1 342 366 INJECTION VALVE 0.08 2 $150.85

I doubt that the injectors are the problem with that mileage though. These are extremely reliable parts. Suspect you have a fuel filter or fuel flow issue. Sending the injectors for cleaning and flow rate testing is a good alternative to new in any case. Normally there is nothing wrong with them other than varnish buildup and this is easily remedied by a shop with the right equipment.
Speed?
My 2000 1100RT has done 126 MPH (clocked by GPS, not the speedo which reads HIGH) fully loaded in the Oregon desert. So 109 MPH is a bit anemic and something is wrong.

- Start with the basics. Spray some solvent (WD40 works) around the intake tubes and throttle bodies and look for leaks indicated by an increase in idle speed.
- Do a leak down test as Anton suggested to determine condition of cylinders etc.
- Replace your fuel filter and internal tank hoses while you are in there with R10 rated submersible fuel hose.