Phil Brookman wrote "very interesting robin have you heard any downside at all with these engines like overheating or and is dual ign possible?"
There was a mention of overheating valves on a BMW R100 a few posts ago, however, I haven't heard any issues with the R1X00 series, but that is not to say there aren't issues. Obviously the manufacturers will not publicise such issues to loudly. The engine is air cooled with the heads being oil cooled, so if you keep the oil cool enough that should minimise any valve problems. The engines have the capability to fit 2 oil coolers if necessary. The only downside, if you could call it that, is the BMW engines, like all Bike engines, run fairly tight tuning, that is, you need to keep as close as possible to the original induction and exhaust systems to obtain maximum power. Duel ignition apparently is standard on engines manufactured after 12/2002, for engines prior to that, I am not sure. There was a BMW R100 in Canada that was mated to a Rotax C box and they installed dual ignition in that engine for around 300CDN. Website here: http://www.ultralightnews.com/engineinfo/bmwconversion.htm In all honesty though, if you were going to pay the money for a brand spanking new bike engine, you would be better off buying a new Jabiru 2200, as the centrifugal clutch in the BMW gearbox may need overhauling at 400HRS and they recommend a full overhaul at 800. The late model Jabs have a 2000 hour TBO with a requirement for a top overhaul at 1000. For an extra $1000 or so, you can have a certified Jabiru with even less weight than the BMW that can burn 98RON unleaded. And 85HP is plenty for an average weighted KR2, especially as your firewall forward weight is below 140Lbs. As I see it, if you can find a good used BMW engine or a good running bike, you may be able to save a significant sum of money (over the Jab), and about 70Lbs over a Corvair. The B2X cherry builder in my previous post said he brought a BMW R1100S off Ebay, and after selling off everything he didn't need, the engine only cost him $1000EUR and then the $1500EUR gearbox, for a 100HP engine. A good deal. There is also the fuel consumption issue to consider; the Corvair's cruise at about 4.5-5GPH, Mark L feel free to provide your figures please, and the BMW "may" get down as low as 3-3.5GPH so there is the longer endurance for the same power. If you have a header tank but no wing tanks, you may not need to consider installing them, assuming your KR is flying that is. Cheers, Rob. Robin Wills Second Person, Pacific National KR-2 19-4594, Ser# N111 krvia...@bigpond.com