Dnepr/Ural reduce fuel tips

2012-06-14T09:41:00.003-07:00

Hello everybody,
In most of classic bikes owners knows about high level of fuel consumption, but how it can be reduced? Let's try to reduce this level, check out an information below about this process on russian motorcycles Dnepr Ural with sidecar.
There are a lot principes to reduce fuel consumption, like to check out tire pressure or driving dynamics, but this princips can't reduce a lot. The main things, what we look out will be carburators, ignition system and final drive.
Carburators - is used to blend air and fuel. The stock carbs remove and throw out. I suggest to put another ones with diffusor diameter 34 mm, I have used Keihin carbs from Kawasaki ER-5, it has 2-cylinder 500 cubic cm engine, on dnepr/ural engines are 650/750 cubic cm, but don't think about engine capacity, because Dnepr/Ural engines performance is less than Kawasaki. The general parametr is max engine horsepower on kawasaki is 48 hp, Dnepr/Ural 28,32,36 and 45 hp, that means, what carb flow rate (performance) will be enough for Dnepr/Ural engines. Under carb adjustment I putted fuel flow bolt to min level and position of carb needle to min level, under different engines it can vary. Carb bracket consist from 2 parts - rubber and handmade bracket to cylinder head. Of course air flow filter required with zero resistance. If you are using stock air box, you can put in K&N filter for Kawasaki VN1500 (Vulcan) 99-, size/dimension will fit in to the filter box. Check out the image:

Finally, needs to add fuel hose to each carb and gas hawsers.
Ignition system - calculation of ignition moment, stock contactless ignition remove and throw out contact and put in car sensor. The shutter is hand-made. Ignition coil can be used genuine.

Distance from sensor to shutter about 1 mm, main purpose: on shutter must be 2 simmetrical notches to imitate crackshaft frekvence, because camshaft frekvence is less in twice than crankshaft. If you don't want to make it by own, you can buy it on ebay ignition kit.
Ignition module - include ignition control unit and commutator. Control unit is hand-made as well on PIC controller base + octane correction, depening of fuel type using, commutator has been taken from car. Ignition module are located under seat.

Well, last thing has been left is changing stock final drive (8/37) for 9/35, it can be found at ebay as well.

After those moifications overall fuel consumption has been reduced from 13L/100km to 5.5L/100km on driving with sidecar at speed 80-90 km/h.
If there are any questions, comment the post. Regards.

How to reduce fuel consumption on Dnepr Ural motorcycles

Dnepr/Ural reduce fuel tips