Query Approved

What oil grade was used in the 3rd service?
Was the oil filter changed?

Primarily, check the chained. Clean and re-lube it.

How's the performance upto 7krpm?

These question should give a better idea.

But its hi-time you hit the SVC for a checkup.

its always been the Yamaha recommended oil,and yes the oil filter is too changed,chains are in good conditions i use motul chain clean & lube-road.obviously it struggles after 7- rpm well there's kinda of smoothness till 7, but beyond that, too much engine vibration, handle bar wobbles,and coolant level is fine, and i change engine oil at the perfect interval,but still cant fig out the problem is.

^^^ Looks like cam issues, atleast this is what happens with CBR 250R. But cams are not likely to be worn out so soon. May be PM sridar1983, he's an automobile engineer & could give you some insights.

When was the last time you adjusted your tappets...?
Did the mechanic try to do this in this service?

Typically the tappets needs adjustment only in about 10000KM (IIRC)


(Aargee the issue on CBR is also to do with the valve (shim) clearance and not to be generalized as "cam issues" .. :P )

Shim issues do not restrict with going beyond certain RPM; for instance, when I was doing our Bekal ride, the clearances were not acceptable, yet I could hit the top speed with no issues, just that there were additional noises.

Was the valve clearance adjusted in this service. If so a low clearance will hamper the performance. A loose tappet will only make sound but a tight tappet will hamper the bike to rev to high rpm. Get your tappet checked if it is too tight.

hmm... now am really starting to doubt on tappet and camshaft, so can there be any chance of mis adjustment in clearance,if the bike fall, ive droped ma bike once not hard, the stand retracted and the bike moved away and fell , and regarding km clocking the odo reading is abt 6800km[6 months old] i havent checked with srvc guys coz am in a rural for now so, am worried will they have a clear knowledge abt fixing it what is ur suggestions ppl??

A casual fall from stand will not cause any serious engine problem, and at worst may cause broken fairing and turn indicators...The Valve clearance is to be checked and adjusted in new bike at at 5 k kms since it also undergoes run in/setting in process....Get it checked and adjusted with ASC.

Since you say you are now at the outskirts of city,be careful of where you fill your petrol from..Fill petrol from a reputed Company owned bunk, as adulterated fuel will bring down performance.

As satyenpoojary and others mentioned, this problem is related to tappet. Since you are saying the engine is not able to rev high, it should be because inlet valve tappet is lose and exhaust tappet will be tight.

lose inlet will not allow engine to get enough airfule mix

and a tight exhaust tappet will causes loss of pressure and bike will not be able to rev higher and will not have power because of leaking compression. ask the service guy to remove cylinder head cover and check the exhaust cam. and if you see deep scratches. ask him to loosen it for now and get it replace in warranty..

if you find a tight exhaust tappet, its better you ask them to change cylinder head. becasue of combustion happening while exhaust is leaking. the carbon deposit on the exhaust valve guide will cause compression leak even after adjusting the exhaust tappet.

Second reason could be, a short circulate in bikes electrical at the time of water wash could have cause a problem and ECU will automatically go to safe-mode. but in your case its the exhaust valve.. please get is checked asap..

Hope this solves your problem.

thank you for hearing my distress call,now is it like automatic stuff those tappets valve gets loosen and tighten itself?? and abt carbon deposit can it take place within 700km?? i mean i always use graded petrol like premium or speed!! and thank you so much for enlightening me.. now the problem is i dnt even know guys here could fix it even though i explain it...
points i should do is
1.tighten inlet valve tappet & loosen exhaust tappet ..right?
2.remove cylinder head cover and check the exhaust cam
if scratches are found
3.get it replaced ASAP
4.If tight exhaust tappet is found change the cylinder head..right ?
what if there is no carbon deposit? still has to go with replacing??

You are always welcome my friend.

Here is what you need to do,

Take you bike to ASC and tell them there is no power and no compression and you feel exhaust valve is tight. then they will have to check the valves. stay with them and look at the condition of the exhaust cam. if you look at inlet you will get the idea of how it should be, if you see wear in exhaust cam. tell them that would have affected valve seating also. if they say no sir. ask them to show you valve seating condition.

once the cylinder head is removed and cam's are removed. valve will be in place because it is spring loaded. ask them to use pincher tool to pinch the exhaust valve and you will see exhaust valve sticking out.. then it will be easy to inspect the valve seating.. if there is uneven surface in the tapper of valve seating, compression will leak. if it is a normal mechanic, he will take it to lathe and will grind the seat but in ASC they will replace the cylinder head since cam and valve seating is not proper..


in the diagram below you will see seat width.. that's the contact area that seals the valve seat on the cylinder head. and if there is leak.. then you will not have compression.



Hope this helps.

Edit: Found a better picture

thank you sridar1983 i under stood and what could be the cost i can expect for fixing everything??,when i bought my bike i had those radiator problem till my second service.. that the engine always heats up and turning on the heat warning led...but then i took it to the svc those guys said me it might be due to some electrical problem..and i didnt take it serious coz i had those projectors and all those stuffs and thought may be due to electrical wiring..but it happens only at low rpm drive like in city traffics, but on long ride at high rpm and speed,the led wont come on...and at the 3rd service the guy who serviced my bike said that there's very low coolant level and toped it up.. and after that the led wont come on even at city traffics... and then vibrations have drastically reduced....but when i had those coolant problem i did my top speed test,so can this be the reason like engine overheating for such a misfortune to happen compression leak and valve clearance problems?? and can some tell me a very good reputed svc at chennai.. no matter how far..... BTW am living @ nesapakkam...sri motor sucks..lol

PM SriramEFunds, he might be able to help you.