Re: Discover 125 ST - Huge vibrations and low mileage

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Re: Discover 125 ST - Huge vibrations and low mileage

Mileage of 50kmpl isn't low for a 125cc bike , IMHO .
Fuel Efficiency depends on lot of factors , like .... riding style , traffic conditions , road conditions ...
can't say about the vibrations though.

Re: Discover 125 ST - Huge vibrations and low mileage

This isn't the solution. Let's troubleshoot the issue.

AFAIK, recommended oil grade for BAL bikes is 20w50. Now, you're running on Shell oil. Most probably, that is a 10w40 oil.
So, you've prolly shifted from a xxW50 oil to xxW40 oil and hence you're experiencing more vibrations. Get that checked and sorted out.
Apart from this, get your air filter cleaned, spark plug checked and replaced if necessary and get the chain sprocket cleaned with diesel and get it lubed with generous amount of grease.
Maintain proper tire pressure.

Do this first and revert back.
We'll dwell deeper if the need be.

Re: Discover 125 ST - Huge vibrations and low mileage

Like Divya Sharan mentioned, try those initial steps first. In addition to that, vibes are also causes by loose nuts/bolts, have the foundation nuts/bolts tightened.

Also, since the engine being 125cc, it will be having vibrations which would come post 40kmph. And at 70kmph, the small engine is supposed to vibrate mate.

Re: Discover 125 ST - Huge vibrations and low mileage

@kabir848: No, two of my friends who ride this same bike are getting mileage of 55+. My riding style is as it should be for any 125CC bike. Mostly in 50-60, because most of my travelling is on a highway. I never stretch any gear. 1 0-10, 2 10-20, 3 20-35, 4 35-42, 5 40-42+
@Sal: I agree a small engine will vibrate, but not so much so that hands of the rider would go numb. I have ridden this same bike of my friend. Engine does vibrate above 60 but it is easily bearable. Also these vibrations are in each gear. Even if I try going couple of kph more than the range I specified above, engine shows a big drag. Service center mechanic said that he tightened bolts of chassis which he told me is a solution for engine vibrations.
@Divya Sharan: I said I was on the verge of selling this bike because since second service I have been struggling to get this issue sorted and I am tired now.
For discover 125 ST oil grade is 20w-40 as it is mentioned in the manual. I had motul 2ow-40 after second service. After 3rd service I had motul 20w-50 and then I got bad mileage.
All the suggestions you made have been carried out. I got air filter cleaned a month back. I gave bike for servicing just a week ago, so they cleaned it then as well. Got carb cleaned. Greasing is proper as rear tyre when rotated spins freely for good 6-7 rotations.

Re: Discover 125 ST - Huge vibrations and low mileage

Ok, few things first.
So, W40 is the recommended oil grade and I presume you filled Shell xxW40 this time. Then, that's taken care of!
You said your bike's carb was cleaned. Why? Were you facing issues with the carb?

I mean, have they set it to factory spec? Maybe its tuned rich.

Post a pic of your spark plug here.

P.P.S - Mileage depends purely on one's riding style. I may get x kmpl while you may get y. What RPM band/speed range do you upshift/downshift?

Re: Discover 125 ST - Huge vibrations and low mileage

I told mechanic that there was huge mileage issue so he went ahead and cleaned the carburetor. I am pretty sure that he didn't reset the AFR ratio. He actually seemed to tune it for mileage.
Mileage isn't a big issue as it seems now. Vibrations are much more severe than before. It's sapping all the fun of riding.
I mentioned in my previous in which range I shift the gear. As for RPM band, there's no way to tell. Khadoos, kanjoos Bajaj omitted tachometer from this bike's console. I really wonder by what a great number would the sales have been dropped if the tacho of a few hunderd rupees was included !!

Re: Discover 125 ST - Huge vibrations and low mileage

I suggest you open the manual and cross verify the number of turns on the AFR screw for optimal riding. (best of acceleration and average)
Tuning too much for mileage would induce roughness and hence, vibrations.

Re: Discover 125 ST - Huge vibrations and low mileage

Tuning the carburetor rich also causes vibration. Had happened to my bike, the carb was tuned pretty rich and i used to get vibrations on Low rpms. Tuning the afr to correct ratio had resolved the issue for me.

Well, since you mentioned that "Also these vibrations are in each gear." There is a high possibility that these vibes could be due to the badly set-up Scissor gear. Try searching for a good Bajaj ServiceCenter, and ask them to do Clutch Loading.
Also, could you tell where are you from?

Re: Discover 125 ST - Huge vibrations and low mileage

i doubt if he has tuned for rich setting as mileage seems to have improved a bit. i will tell them about clutch loading although i highly doubt whether they know this term.i am from borivali, mumbai

Re: Discover 125 ST - Huge vibrations and low mileage

Hey guys. I showed to mechanic from which I have been doing servicing. He said that's all we could do, if you want you can take it to sai service mechanics (that's a big bajaj SVC in borivali). So I said fine I will find someone else. So I came to know about this another mechanic. He's pretty good.
I showed my bike to him. He returned the bike with air filter replaced. He showed old air filter to me. It was in pretty bad shape. Paper folds on the air filter were badly bent from sides. Previous mechanic must have fitted it wrong way so it must have been damaged. After this new air filter is in, bike is showing a lot more smoothness. I gotta check mileage now. Fingers crossed

Re: Discover 125 ST - Huge vibrations and low mileage

Hey guys, one month has passed since I got the damaged air filter changed. For 2-3 weeks bike showed amazing buttery smoothness in the engine. It literally glided between the speeds of 50-60. Mileage was 55 kmpl confirmed. Now after a month. Smoothness is gone, vibes are back. Though not same as those finger numbing ones. Mileage has again hit the rock bottom figure of 45-50 kmpl, not higher even on highway. I don't know what to do now. My new mechanic is surprised at this, even he is running out of his options. Feeling really sad now

Re: Discover 125 ST - Huge vibrations and low mileage

Check your bikes wheel bearings, if the vibes are due to engine there could be no of reasons, tuning getting bad, did you changed your bike's engine last time you got your filter changed engine oil is an essential part check the oil for viscosity, clutch plate can also make the bike a bit vibey, to check whether the vibes are caused by engine or not, accelarate your bike to 60 or 70 km/h and then pull clutch, close the throttle completely while pulling the clutch, if the vibration goes away when you pull the clutch if indicates valve adjustment and timing chain issue, when you adjust your valve give them a bigger tolerance.

Re: Discover 125 ST - Huge vibrations and low mileage

I again sent bike to mechanic. He said wheels are fine. And he's outright denying any problems saying bike is brand new there shouldn't be any issue. He returned bike now it's even more viby. Tremendous vibrations at 50kph. Vibrations go through my feet and ass at the speed of 60kph and I jst cant go beyond that speed. Acceleration has gone way down. I am sure he has turned the mixture lean. Mileage seems to have improved. But I don't want mileage at the cost of drastically reduced acceleration. Now he is denying any other solution saying ab aur kuch nahi kar sakte hai. Please can any one tell me where the AFR screw is located? Also please let me know any good mechanic if anyone knows. I live in Borivali, Mumbai