Engine ticking or clatter on startup.

[shreeshar7]

The bike makes quite loud..ticking/clatter sound on startup..the noise stays for like 30 secs and then it runs normal..
Took in the bike to the dealer today..,they said it is tappet noise so they removed head cover,checked clearances, replaced one of the intake side shims, and exhaust side camshaft because it had scoring marks on it.
The camshaft holder ( journal bridge) too had a bit of scoring but they put it back and started the bike.

The clatter is again there.. Doesn't depend on bike's temperature.. If the engine is not running for lets say 2 minutes and then I start it, the clatter is present, goes away after 20-30 secs..

The clatter comes back if I turn off the engine for even a minute.

This issue isn't solved by my dealer and he's not able to find the fault.
Help!

 

[Fangfactor]

Maybe check cam chain tensioner?

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[oneupmotogarage]

Could it be a sticking starter button? Logic behind that question is that if you hold down the starter once the engine has started the starter bendix will stay pushed into the flywheel gear and can make some bad sounding noises. I haven't tested if this happens with the 390 specifically. But its possible.

If not that, and it is definitely a top end sound, It could be a sign of low oil pressure, does the oil light stay on longer than a second when the engine starts? How many miles are on it?

 

[shreeshar7]

Could it be a sticking starter button? Logic behind that question is that if you hold down the starter once the engine has started the starter bendix will stay pushed into the flywheel gear and can make some bad sounding noises. I haven't tested if this happens with the 390 specifically. But its possible.

If not that, and it is definitely a top end sound, It could be a sign of low oil pressure, does the oil light stay on longer than a second when the engine starts? How many miles are on it?

The engine was rebuilt 2 month back..the entire engine!

It has done around 4000 kms..
There was a recurring low oil pressure issue for a long time which these guys couldn't rectify after repeated attempts.. Later it was found to be evacuation pump strainer twisted. They then replaced it.
At one point of time these bastrds had cut off the oil pressure switch wire so that it doesn't show low oil pressure.

Now its plugged it but doesn't show any warnings... Although I'll check oil pressure again.

One of us journals in cam holder bridge was scored to some extent.. Could that cause an issue like this?

 

[shreeshar7]

Maybe check cam chain tensioner?

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Will check that.. Do the 390s have. A hydraulic cct?

 

[Fangfactor]

Will check that.. Do the 390s have. A hydraulic cct?

I pretty sure its hydraulic. Ive read they can be temperamental with low oil pressure

 

[shreeshar7]

So are you suspecting a bad CCT or the motor actually have low oil pressure?

I'm not able to fix on one since the motor has had history of low oil pressure.

Please suggest me on what to try replacing or check next?!

 

[Fangfactor]

With your motors previous history of low oil pressure and the excessive cam wear, scoring etc I would be getting that checked again to be safe.

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[Fangfactor]

A second opinion from another qualified KTM mechanic would also be a good idea. I wouldn't ride it until you have this sorted or you will most likely end up with another blown motor. Good Luck.

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