SWIFTSHASHI

Hello all,
I've been facing problems one after another on my XCD 135 DTS-Si bike,for the past 2 months.Before that,the bike was in excellent condition with a mileage of 70-75kmpl and was in touchwood condition.I'm presenting the case history and problems I'm currently facing.
History-One day the tachometer started dancing,I mean,it used to go on its own to 12k rpm and come back to 0 rpm and so on during normal city ride,and the engine also started misfiring.On inspection,it came as a loose wire near battery,which goes into a white cylinder sort of thing, and the service advisor asked me to tighten it whenever such problem arises.He also mentioned that the part acts as a voltage regulator sort of thing with some Xvolts coming inside it and Yvolts going out of it.I don't exactly recall the part name..After two days,the clip of the wire which hooks itself to the cylinder's termina, burnt,which I replaced using horn clips.The service advisor asked me to replace the entire electrical system of the bike as there is no separate part for the clip.But I ignored him as the bike was perfectly normal on that setup.

Current problems
1.Poor pickup till 3k rpm-Its not exactly poor,but the throttle response is not the same it used to be earlier.The exhaust sound below 3k rpm is also changed,it feels like the sound when the bike starts to go in reserve.

2.A peculiar misfiring sound like "BHAD-BHAD" comes from the exhaust when I leave the accelerator to decelerate.However no jerking is felt.

3.When I try to ride slowly(for example 30-35kmph @ 4 th gear @3k rpm) and keep the accelerator constant,the bike sometimes jerks and this happens only when the accelerator is open just 1-3%.I hope you understand what I mean to say.WHen the throttle is generously open,this problem doesn't occur.

4.WHitish smoke appears from the exhaust then the bike is revved to 9-10k rpm in neutral.Is it normal??Also black soot formation has occured at exhaust tip.

Some relevant information regarding my bike which may help you to diagnose
1.Parts changed:
--Spark Plugs
--Clutch Plates
--Air Filter
2.No drop in engine oil level.
3.Mileage-70-75kmpl
4.Odo Reading-23456kms
5.Have always used unleaded fuel(No extra premium or High octane fuel).


Kindly help me,I'm in a great agony due to the pitiable condition my bike is in

sunilg

Query approved.

__________________
(Been There Done That) x 3.25

Join xBhp On

cmahajan

This may be due to irregular supply of fuel. Have you checked the fuel supply to the cylinder? Make sure the fuel supply pipes are all clear of any smudge. This may be due to others reasons as well though.

Not sure why this may be happening.

Again, may be due to insufficient supply of fuel to the cylinder. When the throttle is wide open, the fuel flows, when the throttle is only slightly open, the fuel doesn't flow properly. Just a guess.

White smoke appears when the oil mixes with the fuel in the cylinder. This may also result in carbon deposition in the silencer and its tip. This may be due to a damaged piston. I think changing the piston rings would solve this issue as a proper seal would be created again between the piston and the walls of the engine cylinder.

A good mechanic should be able to help you with all these problems.

__________________
Signals which are timed for 50 Kmph are also timed for 100 Kmph :)

SWIFTSHASHI

thanks a lot for the prompt reply.
Some queries-
1.What will be the cost of piston rings??and will it be available as a bajaj genuine part??
2.Can piston rings get damaged at such a low mileage??The service advisor told me to get the entire block piston set along with valves changed.

Observation-Today I observed oil accumulation on my 1day old spark plug.This is the first time I'm seeing this.The old spark plug didn't have them.

Pinaki

Oily plug is clear indicator of worn piston rings . Clean it once with carb cleaner and re-check to be sure after a few days riding .
Also have the carburetor disassembled, cleaned and worn parts replaced in it .

Honda_CBF

+1 to pinaki ji.
@ Swiftshashi,
your slow riding problem is exactly like mine..
I guess its cloged pilot jet or/and damaged diaphragm. (mine was the diaphragm)
piston block set should cost something 3- 4k Rs.
Btw, first get your carb cleaned and tuned then we will move onto other problems.
And yes rings can get damaged even in low mileage running, lots of factors are there to do that.
Also, were do you saw the oil deposits? Spark plug's electrode or the threads or both areas??

__________________
http://www.facebook.com/ateesh.kumar

SWIFTSHASHI

Thanks a lot members for the replies.

The oil deposits were seen near the electrode and the threads also.

My query-Is piston ring and diaphragm of carb available as a genuine spare??and what is its cost?the reason i'm asking this is that the workshop mechanics always try to push you towards the more expensive form of repair.

Honda_CBF

oil on the spark plug electrode means oil is coming to the combustion chamber so it seems rings and/or valves and/or valve guides are gone.

Yes, genuine spares are available but its possible that they may come in sets. So rings are with block piston & diaphragm with the new carb.
But there are also reliable aftermarket spares, dont know much about them may be others can help

__________________
http://www.facebook.com/ateesh.kumar

shoeb2015

Whitish smoke is clearly indicating that you are burning oil.
Piston rings may be worn-out,hence compression has decreased and engine is misfiring.
Check oil regularly and see how much oil it is burning per 100KMs that shall give you a clear idea about the condition of rings.
Clean the carbureto are replace all the worn out parts.
Check the ignition coil(cylindrical object you mentioned earlier) and cdi for any faults as it can also create misfiring issues.

rakowli

First of all, clean the carburator and the jet and get it properly tuned from a good mechanic, if you can get it cleaned and tuned from outside mechanic. This is because i have P150 Dtsi which had similar problem as i have K & N fliter installed which requires upjetting, my bike tuning was not proper and it used to give white smoke and had a low pick-up. but once i got it tuned proper from some other mechanic everything was fine, no piston rings replaced nothing done. So before replacing just try doing this. If it helps it would save your money.