Knocking/ Clanking Noise from engine 5-6k rpm's

[raminlive]

Guys, I'm posting here after too much of frustration with the KTM service for the last 3 days. Mine is a 2015 RC 390 and I'm hearing a very unusual clanking noise from the engine when I accelerate hard between 5-6k rpm's under load and vanishes off post that or less than 5k revs. This is not valve clearance sound as this doesn't happen under idling conditions. The clanking noise is not present when the bike is revved without load.

I'm suspecting the one-way clutch or the rotor bolts that are off the torqued specs but the KTM guys are saying it's common. I again proved them by riding a friend's 2015 RC 390 which has no sound. I have a ride coming up this weekend and I really need assuring answers to sort this out or my annual ride plan would get cancelled with a bike I'm not sure when it would break down.

Pls. help..

 

[John390]

I'm not riding it, so I can't hear it or use any of my other diagnosis skills on it, but I have an idea to have a look at before you dive into the engine.

Check your chain tension. Mine was loose and it made wierd engine knock sounding noises. If the chain is flopping around against rear parts it can sound like that.

it could certainly be your engine or trans, or clutch related, but have a look first.

that said, I had an older bike that I rode for years with a noisy clutch. it was scary at first but it never caused any problems

 

[raminlive]

I'm not riding it, so I can't hear it or use any of my other diagnosis skills on it, but I have an idea to have a look at before you dive into the engine.

Check your chain tension. Mine was loose and it made wierd engine knock sounding noises. If the chain is flopping around against rear parts it can sound like that.

it could certainly be your engine or trans, or clutch related, but have a look first.

that said, I had an older bike that I rode for years with a noisy clutch. it was scary at first but it never caused any problems

Hi John, thank you for the inputs and really appreciate the time taken to reply to my query.

I've given the bike to the KTM guys who promised to have a look at the issue. I shall keep you posted on the findings.

Thanks again John.

 

[raminlive]

Hi John, thank you for the inputs and really appreciate the time taken to reply to my query.

I've given the bike to the KTM guys who promised to have a look at the issue. I shall keep you posted on the findings.

Thanks again John.

Took the delivery today. Issue was found to be decomp valve spring which has weakened itself over time. As KTM doesn't provide the spring or the decomp valve assy alone need to go in for a full exhaust cam replacement. Costed about 60$ with labour including valve clearances job. Bike is super smooth now and no clanking noise.

 

[KneeDrachen]

that's incredibly inexpensive if that is in USD. Where are you located?

 

[John390]

$60 is expensive to replace a whole camshaft??