Derbi Senda Excessive Fuel Consumption?

Its the main jet after a certain amount og miles it needs to be changed as it gets bigger, and the bike wont be running at its best.

In my case the spark plug was all the time wet with fuel

DD
October 2014

Those spanish bikes are very cheaply made and come out with widely different power outputs and often fail. They also require careful running in, something a 16 year old chav is incapable of. Their built like cheese bricks

Mark Wildman
April 2011

UPDATE
The bike passed its MOT (Thanks for asking Adam).
I've reset the carb and replaced the gasket by the flot bowl because there was a small leak when the bike was parked .
I have a new fuel tap on order , should be here any day now.
Clocked the full usage carefully last night , it now appears to be doing 17k/litre and I think that works out to 48 mpg . Still not good but a big improvement.
Will be checking the crankcase thing next.

John (Riansdad)
April 2011

rians dad hi i have sent your seals off to you ! wierd to find you on here isnt it there are a few that can cause this
firstly does the bike run ok ?if so then the main jet must be in there but its possible that theey place who rebuilt it either fitted a bigger jet or made the jet in it bigger for some reason,the most common cause for fuel usesage that high is in fact a leaking needle or poorly adjusted float which can allow fuel to travel through the carb into the inlet manifold and into the crankcase,now really this shouldnt happen as your bike has a vaccum tap i think but these do fail pften and also the overflow pipe on the carb should allow the excess fuel to run out of it but this can also block up and as i said if it runs into the crankcase it will fill the crankcase and leak through one of the crankseals which in your case will be the right hand one as this leads to the gearbox/clutch area of the engine.so try taking the oil drain bolt out and see if its amount is higher than it should be and also see if it smells of fuel,do this first to see if its doing as i suggested it may be good luck mate you will get your seals soon and good luck with the mot.ps the amount you said they wanted to do the job is a bit high it should be about £70

adam bike doctor(of milton keynes motorcycle centre)
March 2011

try second gear!!

No idea mate sorry, check the fuel mix in the carburettor, check for signs of unburnt fuel like a petrol smell off fumes after the bike has warmed up.

Maybe your son is putting in £4 petrol and buying 10 cigs lol, i did that

Alex, amateur scooterist
March 2011

check carb to see if main jet has fell out.

rayb
March 2011