Bajaj Discover high fuel consumption

[t_han123]

I have a Bajaj Discover 100 (5 Gear) model manufactured in 2011. I bought it about a year and a half ago and it was doing about 50kmpl. But now the fuel consumption is around 35-40kmpl and hill climbing performance is significantly reduced. black smoke is coming while accelerating at idle position. It was a lot in the beginning, but now it is less due to a recent carburetor adjustment. Also, I heard this model should perform an average of 65kmpl.

Since I did the carburetor cleaning and adjustment, what could be the other possible reasons for reducing fuel consumption?

Edited February 17 by t_han123

[Riz]

Bike is almost 14 years old.....Well looks like........you need to go for an engine overhaul...

Remove the spark plugs and see whether there are oil and / or carbon deposits. If it is oil then an engine overhaul, probably replace the piston rings etc............

[AVANTE]

On 2/17/2024 at 7:32 PM, t_han123 said:

I have a Bajaj Discover 100 (5 Gear) model manufactured in 2011. I bought it about a year and a half ago and it was doing about 50kmpl. But now the fuel consumption is around 35-40kmpl and hill climbing performance is significantly reduced. black smoke is coming while accelerating at idle position. It was a lot in the beginning, but now it is less due to a recent carburetor adjustment. Also, I heard this model should perform an average of 65kmpl.

Since I did the carburetor cleaning and adjustment, what could be the other possible reasons for reducing fuel consumption?

How many kms on the engine? You may need to go for a rebuild if you are seeing signs like white smoke, Hard start, oil burning etc. 

Like the above comment said, checking the sparks are a start.

You might be better off replacing that carburetor as well next time since the Discover/Platina 100 carbs are not too expensive. With lankan fuel quality, you need to be cleaning them more frequently depending on usage. 

[t_han123]

On 2/22/2024 at 2:28 PM, Riz said:

Bike is almost 14 years old.....Well looks like........you need to go for an engine overhaul...

Remove the spark plugs and see whether there are oil and / or carbon deposits. If it is oil then an engine overhaul, probably replace the piston rings etc............

 

On 2/23/2024 at 5:26 PM, AVANTE said:

How many kms on the engine? You may need to go for a rebuild if you are seeing signs like white smoke, Hard start, oil burning etc. 

Like the above comment said, checking the sparks are a start.

You might be better off replacing that carburetor as well next time since the Discover/Platina 100 carbs are not too expensive. With lankan fuel quality, you need to be cleaning them more frequently depending on usage. 

 

It's about 65000km if previous user didnt do any mislead meter correction and i think engine has rebuit once before I buy it. Some carbons are in left plug and oil deposits in right plug. But no visible white smoke, but black smoke is coming when accelerating. Only little bit of oil has burned for over the period of 3000kms (from top level to mid level) What is the meaning of these signs?

[Riz]

Difficult to figure out , 

few tips....If you know about carb operations and adjustments.

a) Remove the carb and partially block the jet fuel passage

b) Adjust the fuel / air screw to the leanest level

If sorted, then change the carb repair kit.

and if black smoke still persists, as AVANTE suggested..... try your luck on a new carb.

But at 65,000 odo level, carb should be good enough to run another 20000 / 30000.

 

[t_han123]

2 hours ago, Riz said:

Difficult to figure out , 

few tips....If you know about carb operations and adjustments.

a) Remove the carb and partially block the jet fuel passage

b) Adjust the fuel / air screw to the leanest level

If sorted, then change the carb repair kit.

and if black smoke still persists, as AVANTE suggested..... try your luck on a new carb.

But at 65,000 odo level, carb should be good enough to run another 20000 / 30000.

 

I don't have much knowledge about carb adjustment. First, I am considering changing the spark plugs and seeing the difference since they are still old now. According to the result of it, move to the other steps. Is it a good initial solution?