Engine noise 26k - Comments appreciated
 

Hi there my 08 XTX don't sound so sweet.
Smooth running motor up until last month.
First thing to catch my attention was a metallic buzz/rattle at mid revs,
followed after a week or so by what I thought was pretty loud tappet sound.
(I know they can be fairly loud, but this caused me concern.)
So I changed oil and filter. Then I adjusted the valve clearances, they were mostly too tight.
This made a difference but not really what I would call fixed.
Next day the tappets seemed loud again, so I checked again, ok maybe at the loose end of the tolerance so I made very small adjustments to exhaust side.
All adjustments with a cold engine.

Still not happy, so went to Yam shop for advice. aiming my concern at the cam-chain.
Bloke revved and listened and said sounded ok, I wasn't so sure.
Bloke said 'just general engine noise, not to be concerned, XT's are pretty noisy engines anyway' hmm.
Now I know what my bike sounded like, I ride it every day, it has suddenly changed recently.

I've looked at the cam-chain adjuster and that 'seemed' ok but I've ordered a new one anyway.

symptoms are:-
metallic buzz/rattle at mid revs.
general loose rattly sound when blippin' the throttle if stationary. and when decelerating when riding.
tappet sound much louder than normal
ALL THE ABOVE SOMETIMES CURES ITSELF - JUST FOR 20 SECONDS OR SO (reminding me that the bike used to be much more quiet) then resumes noisy operation. usually when at lights but probably only once a day.
Also a 'sweet spot' about 3rd revs when riding sounds quieter then any more throttle causes rattle/buzz.

Like I said new tensioner tomorrow, but the old one seemed ok and had some pressure against chain when re-inserting (without spring)

Would a worn tensioner cause the noisy tappet sound?
should any noise like this come and go? seems odd to me.

Any thoughts appreciated

Loose crankshaft nut? Not unheard of and makes a noise similar to what you are describing which will vary and go quiet inconsistently at certain engine speeds.

Does it sound anything like this...



If it does and you catch it early, it's simple to fix. Just re-torque the nut to 120Nm and no lasting damage to main bearings/primary gears will be done.

yep could be the crank nut, or.......

tho my money is on the chain guide on the tensioner side, mine broke where it pivots at it's base allowing the guide to move up and rattle about

is the tensioner near the end of it's travel? you're going to need to do a bit of stripping to get to the bottom of this one!

Thanks for replies, Always love the folks on this site. :) Genuine help is never far away.

OK, I'll have to do some investigating at the weekend.
No sound on this pc at work, I'll check video clip later.

Thanks.

..and I thought I was an experienced rider.
 

well, after fitting a new tensioner and then getting the shop to check my clearances again for me, the noise had still not gone, getting worse.
Took back to shop and quizzed the guy
but was told my exhaust was blowing.
I was convinced that was not an air noise but a metal noise.
Indeed the rattling on engine-braking sounded like the engine was going fall apart.
At first I couldn't find it, but putting hands over exhaust holes proved the point. then moving the downpipe with my foot, I felt silly.

Struggled a bit to loosen the nuts, but replaced with new nuts and ...tightened the exhaust to the engine ;)

So, �100 on a chain tensioner,
and �80 for valve clearances,
three visits to bike shop.

I just needed to tighten two nuts, DOH.

Feels like a different bike now. Sorted.

hi thats my video :) (i feel proud) the best way to test it is to sit still with youre front brake on put it in gear and give it some revs and try to drive forward the knock will get really bad and sound quiet nasty and always does it on accelaration and decalaration. somewhere on here u will find my right up videos and pictures there is also another of my vids on youtube that show the exact problem. to me it sound like i had killed the bottom end as the sound was coming from just behind and slightly deeper into the motor but the noise mostly disapears under constant speed and revs. i was told by 4 diffrent bike mechanics that it sounded "course" and they could here what i was listerning to but said its just a big single and they are clunky. im pretty sure from what i have red above it is the same thing and if you are slighly mechanical minded all it will cost you is a oil and antifreeze change some locktite and some instant gasket for the rebuild i did mine around 12000 ish (check other article will be more acurate) and im now on 16000 and she is sweet as a nut (HAHAHAHAHAHAHA JUST GOT TO THE BOTTOM COMMENT AND SEEN YOU FOUND THE PROBLEM LOL SORRY LOL IT IS 2.44 AM LOL GLAD YOU FOUND IT . ASH

Thanks anyway :)

Bike mad, i have the exact same sound from my engine,,, id say the exact same noise,,, so exactly what do i do to fix it... if ye know,, thanks,,,john.

How do you get to the crank nut to check torque. Is it just remove an engine casing
or an engine out job? If its easily accessible might be a worthwhile check before a
long trip

All you have to do is remove the right hand engine cover (clutch side) to expose the offending nut. It can all be done with the engine in the frame.