Reply To: “Vienna” B1 with Upsidedown

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As I am working on an engine upgrade with 906 ccm and didn’t finished it since 5 years now, a lucky moment happened at the “Built not bought”. The seller of my big-bore-kit was present and offered me his engine with 906 ccm, a lot of modifications and at least 2000 km used on the road !

Adjustable camshaft sprockets, EX-cam as IN-cam, larger inlet and exhaust valves, 906 ccm, dual spark plugs per cylinder, Ignitech ignition, balanced crankshaft, centrifugal force powered self-boosting clutch, modified crankcase ventilation and the beautiful Keihin CR carbs with funnels.

With these modifications the measured values are 68 HP at 6.800 rpm and 82 Nm at 4.900 rpm. Measured and available at the rear wheel !

Delivery service by my uncle Hubertus, thanks to him !

Mounted the engine right away into my Dirtbike to complete the installation and doing initial running tests. Ok, still preparing for the first run 😉

Finally this engine shall work in the “Vienna” by end of September, ready to race at the Spreewaldring 3rd and 4th of October 2019.

Need to complete the electrical installation, incl. positioning of two dual ignition coils and related ignition cables. Need to modify upper engine holders to fit the two coils under the tank.

Oil supply line outside of the engine are good to avoid untight head gaskets but they doesn’t allow to mount the existing high tube exhaust. Will fiddle with new exhaust, puh.
Peter will help me with that. Will be a 2-into-1-system. Two downtubes slim to the middle, left and right of the oil drain plug and an under-engine silencer, maybe an additional silencer right hand side.

Easy to operate Keihin CR Special with 37mm Venturi.
Intake and inlet valves are matching them 😉
Outlet valves are larger as well.

Ok, let me see how fast I can work to do the first test run with this “Monster” 😉

Cheers, Michael

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