Thursday, June 17, 2010

Boosterplug Smooths it...

I just want to share my experience coping with and finally smoothing a rough running engine in my 2007 R1200GSA…

I bought the bike new, it now has 30K+ miles on it. From day one this has simply been a rough running R1200 (love the bike regardless!). I have owned two other straight GS’s and my keeper bike naturally has to be the one with the rough at idle engine and especially at low speed and low rpm – difficult to ride and shift smoothly when slow. Again, I’ve ridden several other bikes with the same engine and know what smooth feels like, my bike has never been it.

I’ve tried everything, multiple tunes, valve adjustments, computer tweaking at the dealer… it’s just always been rough and I basically conceded to some sort of a balance problem. Then I started reading about Boosterplug (, and other makes of similar products, that adjust the temperature of the intake air downward in order to fool the bike into believing that the OAT is cooler than it actually is. This tricks the fuel controller into producing a richer mixture.

I was hesitant to try it, and then I really took a good look down into my exhaust and could see that there was absolutely no black residue at all, it was obviously burning very hot. This is where I should jump in and tell you that I am a now retired professional pilot and in the piston days spent many hours out of sheer boredom (and occasional necessity) playing with and adjusting mixture. In the reciprocating engine airplane world the accepted practice is to lean to peak EGT (Exhaust Gas Tempurature – approximately peak RPM), and then RICHEN slightly off peak. There are some guys who will LEAN off peak slightly believing that they get better fuel burn and a cleaner engine, but they are in the minority and almost no credible source teaches that (these are also horizontally opposed engines).

At any rate, after reading a couple threads on ADV (ADV Forum - Boosterplug, ADV Forum 2), and especially reading Jen’s remarks at the end of the second link, I decided to take a chance and try it. The plug arrived in very timely fashion considering it came from overseas with no problem, and when I took it out could tell it was very well made and heavy duty. I took off the bike’s left side cover, unplugged the OAT sensor coming from the airbox, plugged in the Boosterplug, plugged the airbox feed into the receptacle, and laid the new OAT sensor alongside the rear side of the tank. Total install was less than 5 minutes, only needed a couple of ties to make it real pretty.

I had read that it sometimes takes 3 engine cycles before the bike’s computer begins to process the inputs properly, but I noticed the difference on the first start and ride. First of all, the engine turns over once and is running, not 2 seconds later, it fires right now! Then idle is stable and MUCH smoother. Slow speed riding has no surges and shifting is way smoother. The bike still accelerates the same, and on high rpm decelerations does not pop and spit near as much as it used to. Overall the bike instantly felt as if I had installed a new engine.

But I hadn’t run it in any warm weather until this weekend. Saturday I rode my wife over to Yakima (87 degrees) via Chinook Pass (50 degrees). Our destination was Los Hernandez Authentic Tamales… a hole in the wall with the BEST tamales I have ever had, the pork as well as asparagus & pepperjack cheese were delicious and worth the ride:

She had no idea I had installed it, and as we were eating Connie remarked that “the bike seems way smoother!” That said it all – and I have spent hundreds tuning and primping never getting measurable improvement.

I checked mileage and it was the same 40 mpg exactly that I always get. The bottom line is I think the bike was running way too lean and this has radically changed its character to the better – well worth it, and it came after I had given up hope for smoothness.

Reading around this seems to be very common with this vintage engine, and not just the 1200. If you are having some of the same symptoms (like engine surging just above idle in low gears), you might want to look into it. I’m sure the dealer may have a problem with it warranty wise and I’m sure the South Sound guys can chime in on that. All I can say is that I don’t often endorse products and I get nothing for reporting on this other than the pleasure of hopefully helping out someone with the same frustration. Install was simply plug and play.