Discover 125 DTS-i mileage problem

[preetam]

I own a discover 125 dts-i 2005 model....my odometer reads 48k kms....of late i am getting very low mileage and its emitting black smoke on high rpms...i hav tried every possible soln.....but its still the same....can anyone out thr figure out whr exactly the prob lies?

[Aryan]

Query Approved.

[braindead]

can you list what all you have tried till now?

i suspect piston rings or valvetrain

[Penno]

It has to be something with the piston rings.

Btw how much is the mileage drop ?

[jd666]

time for overhaul.. Please get bike checked at a good workshop, where they can check the compression of the engine etc.

[preetam]

Before hand i used to get around 50-55 kpl in city and now i am getting 40-44 kpl. Got the carb overhauled....valve timing checkd....spark plugs replaced....head overhauled....pickup is good so i dint get the clutch plates replaced....

[braindead]

if the bike is making a clatter you can narrow down on the rings.

it seems your piston rings are a borderline case. they are holding under low load but letting go at higher load (high bmep)

better open up the barrel and change them before you need a rebore and oversize piston.

i would recommend moving to a better quality engine oil after you replace the rings.

cheers

[preetam]

thanks a lot for ur advice! till now i hav been getting my bike serviced at castrol bike zone. recently i visted bajaj service centre...the concerned person told me thrs a leakage in engine compression. suppose i get the piston rings replaced...which engine oil would u suggest?