@syscrush:
i have seen this engine in various bikes: KTM Rotax, Aprilia, MZ, CCM. most of them have their roots in dirt racing. in fact the engine is from a KTM Rotax GS, see
https://www.google.at/search?q=KTM+rotax+GS&safe=off&hl=de&tbm=isch&tbo=u&source=univ&sa=X&ei=QNCXUbXoGorZ4ASouYCwBQ&ved=0CC8QsAQ&biw=1311&bih=627yes, the engine does have a counterbalancer, and from what i have heard it is not possible to mount the counterbalancer the wrong way (otherwise it comes in contact with the crankshaft).
@TG: its more or less just for fun. but there is a good chance that we will race it in the "Grabtheflag" series.
@scottly: weight of the engine is 44kg.
last thursday the bike had its first rollout at pannoniaring. the first laps i did with my friends ktm-rotax, a 560ccm single racer with 114kg. i wanted to get a feeling for the single cylinder vibrations. the bike had some vibrations, but all within comfortable limits. next turn i tested my new racer and was astonished that all the vibrations on the dyno felt much better on the track. it was very similar to my friends bike. i decided to do some laps and noticed that the bike was more than willing to corner, however it was stable at high speed passages. next turns 4 of my friends did some laps and were very happy with its lightweight and cornering ability. 330mm front brake was disappointing, but things changed during the day. the new brake pads needed some brakin period and after this the front brake performed well.
front and rear suspension was on the stiff side. logical, the rear dampers are from my race guzzi.
the new lectron carb was on the lean side, especially in the low rpms there was a hesitating from the engine side. new needles are in order (as are rear dampers).
in one fast lefthand corner under hard accelerating i had a tankslapper. the steering damper was my friend and i am not sure what happened without it. at home i did some investigations: the bike has actually 70/20° rake and 75mm trail. no wonder that it loves corners (i wonder that it is stable at straight). i am sure that a adapted riding style (more weight at the front wheel) would cure this problem. in addition more negative front wheel travel would help also. more trail means new upper and lower triple clamps. better a flatter steering angle: fortunately i have the steering bearings in aluminium inserts. new inserts bored 2° inclined seems to be the way to go.
but first we will do some more test runs with better suspension, less tire pressure (avon 2.1bar).
stay tuned
mec