Bike suddenly got louder

[rick]

I was riding in to work yesterday and the bike suddenly got louder as I was pulling into the parking lot. On the way home it still seemed louder than usual and my wife commented when I pulled in that the bike sounded funny. It was nice to know I wasn't imagining it.

I bought my RC390 in October and it has about 2,500 miles on it. The bike seemed to run as strong as usual and there wasn't any obvious deceleration popping or anything. Still, I assume the extra noise is from an exhaust leak and I was planning to throw it on the lift tonight (took the Duc in today), pull off the bodywork and try to find the leak or something else obviously wrong.

I was just wondering if anybody had any advice or a similar experience. Thanks!

 

[msquared]

No similar experience but I've been looking at the exhaust as I am about to remove and replace it with the MIVV system. Unless you punched a hole in it someplace (which seems unlikely given how thick that metal is) I would check the clamp at the top of the system first AFAIK that is the only place it could get "loose"

 

[A1VW2NV]

Start with the head bolts, then check the clamp between the headpipe and muffler. Do you remember hearing anything rattling?

 

[rick]

I don't recall any rattling. Just normal engine noise - only more so. Moving my head around, it seems loudest near the footpegs.
It's nice to know that there isn't any well known problems with the exhaust and welds failing after so many miles though.


I'll get it on the lift tonight and probably take it apart this weekend. Thank you!

 

[rick]

Hmmm, now that I've got the bodywork off, the noise seems to be coming from the top end. No obvious exhaust leak. I guess I'll dig down to the head...

 

[rick]

Yeah it sounds like it's coming from the head or maybe the cam chain tensioner area. It might be time for a real mechanic.

In other news, the sheet of rubber covering the head wasn't nearly as hard to get out of the way as people have suggested. Cut four zip ties, discconect the 3 clip-connectors to the throttle body and it could pull right off. You could also snip the rubber once around the hole for those connectors and not even have to do that. Although, I'm not seeing any compelling reason to put it back on. It doesn't even exist in the service manual.

Also, I haven't gone the electrical schematic yet but, w/o the fuel pump connected it won't even try to start. Anyone know which pins I could bridge or whatever to get it to run off a gravity fed auxilliary tank while it's on the lift?

 

[Ryanthegreat1]

Probably won't start with a gravity feed for fuel. I have not looked at the manual for the pressure but most FI systems run 43psi.

 

[rick]

Oh wow! I had *heard* most motorcycle fuel pumps are closer to 3 psi but, yeah, a gravity fed tank ain't gonna work at 43psi!
I've got an appointment at my favorite local shop tomorrow - it didn't connect until after I made the appointment that it's still under warranty. If my favorite shop finds anything big, I'll have 'em button it back up and drop it off at the dealer. Boo.

 

[DCMoney]

Oh wow! I had *heard* most motorcycle fuel pumps are closer to 3 psi but, yeah, a gravity fed tank ain't gonna work at 43psi!
I've got an appointment at my favorite local shop tomorrow - it didn't connect until after I made the appointment that it's still under warranty. If my favorite shop finds anything big, I'll have 'em button it back up and drop it off at the dealer. Boo.

Probably just misheard, 3 Bar is equal to 43.5 psi.

 

[Fasteddy]

3 psi is probably in the range for a non fuel injected bike, like YZF600R which has carbs that sit above low point on tank, the spec KTM shop manual is actually higher then 3 bars, IIRC 54psi was max...

 

[rick]

Wow, good to know!

 

[big_sur]

Yeah, I dk about this bike, but having pulled off a fuel line on another FI KTM, there's a lot more than 3psi. I seem to recall it was around 50psi so I doubt it would run off just gravity.

 

[fs1ephil]

Just a thought. Could the spark plug have come loose slightly?

 

[rick]

I did pull the spark plug in order to do a leak down test. It seemed tight as I was talking it out - there was a rubber boot slid onto the stock Bosch sparkplug that interfered with my 14mm spark plug socket so, I had to use a normal 14mm deep socket and a magnet to get it out. ...er, the point being that removing it didn't go as smoothly as usual so, it's possible that I missed something but, it did seem tight.

 

[rick]

So, I just talked to my favorite local shop and they said that the cam is gold and chunked up and that I should take it to a KTM dealer for repairs under warranty. I called the closest KTM dealer and they immediately started listing all the reason they probably wouldn't cover it under warranty:

"Who performed the break-in service?"
"What are their qualifications?"
"We'll need the receipts for the parts used"

..and what not because they did not perform the break-in service. I double checked to be sure that that is NOT required (see here) but, clearly they're steering that way.

Any advice before I take it over there? Anything I should or shouldn't say?

 

[Fasteddy]

And the next closest dealer is? contact KTM direct...

 

[rick]

Heh, sadly the next closest KTM Dealer is almost 2 hours away from where the bike is now.

I've never had ...er, any good experiences with any dealer as far as repairs go. What little I can't do myself usually gets farmed out to a local shop that only repairs motorcycles. It seems that once they start selling bikes, that becomes their primary business and then the quality of the mechanics starts sliding badly.

 

[Fasteddy]

Before I did my own first service I verified both with my dealer and KTM nort America that it would not be an issue and they confirmed it would not. KTM ph # 440 985 3553 , maybe get the area rep to check it out first before moving it...

 

[rick]

Went to check it out last night (I'll have pictures tomorrow) but, one of the exhaust cam lobes really did just fall apart - a big chunk is missing on the flat part of the lobe. Pretty hard to call that anything other than a manufacturing defect after only 2,500 miles by my thinking.

The other lobe is showing some abnormal wear too. Kind of like this guy found. Hopefully the dealer/KTM won't give me a hard time when I drop it off with them tomorrow.

 

[DCMoney]

Went to check it out last night (I'll have pictures tomorrow) but, one of the exhaust cam lobes really did just fall apart - a big chunk is missing on the flat part of the lobe. Pretty hard to call that anything other than a manufacturing defect after only 2,500 miles by my thinking.

The other lobe is showing some abnormal wear too. Kind of like this guy found. Hopefully the dealer/KTM won't give me a hard time when I drop it off with them tomorrow.

Shit.... Cant wait to see the pic!