Strange noise when I snap the throttle

[slowtacotruck]

Hello, this bike is a 2012 and makes all sorts of noise, most of which I think is probably normal. It has 6500 miles on it. One, if I'm running the engine around 3k rpm and accelerate, the engine runs fine and goes but it seems to be harsh. The engine seems harsher than my klr. I saw that is probably the clutch basket and as long as it doesn't blow up I'll be good with that for a while.

The second noise is when the bike is sitting still and I snap the throttle. When I let off the throttle the engine makes a whirring noise. The noise is pronounced but doesn't last long. The bike is new to me so I'm just trying to see if the noises are normal. I put a few hundred miles on it this weekend with no issues.

Thanks for the help.

 

[Boris]

Noise one is almost definitely the clutch. Ignore and carry on, or put a gen 2 basket in there, I did and it the noise was loads better.

Noise 2, sorry, no idea.

 

[EricV]

If you are snapping the throttle in neutral, and the whirring noise is coming from the right side of the engine, (as you are sitting on it), then it's most likely the cam chain. Nothing to worry about. This design has a very long cam chain. It will rattle on cold start, but shouldn't rattle for over 30 seconds before quieting down. If it does, that's an indication of the Cam Chain Tensioner, (CCT), starting to lose it's ability to maintain tension and something that needs to be addressed.

When you snap the throttle, you are tensioning the cam chain, then momentarily giving it slack when the rpms drop w/o load. Thus the more pronounced whirring noise.

For most bikes, the CCT getting worn happens after 50k miles or so. (there have been failures, but all over 50k miles, some catastrophic, including mine at 82k) Yamaha recommends replacing the Gen I CCT at or before the 2nd valve check/adjustment at 52k miles. If you're under 26k miles, (the first valve check/adjustment interval), you might consider having the CCT swapped out at the valve check time, just to be done with it. Yamaha has superseded the part number for the CCT twice now, so an updated design is currently being used.

If you're snapping the throttle with the clutch lever pulled in, it may just be clutch noise. No biggie either. This is a noisy engine.

Oh, and stop snapping the throttle. It doesn't go anywhere when you have the clutch lever pulled in or are in neutral.

 

[slowtacotruck]

I appreciate the response. I thought it may be a normal operating characteristic of the vehicle but I figured I'd ask since its new to me. Are there any special tools other than feeler gauges required to adjust valve clearance?

 

[EricV]

Not really, it's more effort to get to them than to check. The valve cover is very tight to get out and back in w/o damaging the gasket. Otherwise it's a typical shim under bucket design. I do all my own maintenance, except for this, which I pay the dealer to do. It's just too much of a PITA for me to want to do.

 

[slowtacotruck]

I've heard that a few times. I'm starting to get a little nervous about opening the engine up lol. I've had some engines that the cam and crank gears are not keyed to the shaft and they require timing tools to get the engine into time when you loosen the bolts. Have you replaced the tensioner? Is that pretty easy?

 

[EricV]

With a dual cam engine the cams will rotate slightly when you loosen the chain tension. They do sometimes slip a tooth. The by the book process for replacing the CCT involved pulling the valve cover so you can verify/re-set the cam timing as needed.

The cheater method involves removing the lower engine cover and zip tying the chain to the lower gear under tension, then R&R the CCT, tap the new CCT to release the pre-cranked in tensioner, then removing the zip ties and hoping nothing skipped a tooth.

There are write ups here on the forum, so do some searches to find those threads and make your own decisions. Oh, and it is an interference engine. A tooth off doesn't usually mean a grenaded engine, but a few teeth will mean bent valve and piston hit. Usually just one or two valves and one piston. Not a happy day. BTDT with a CCT failure on my '12 Super Ten. I was still under warranty at 82k, so covered event. I was one of the first to suffer that failure before Yamaha updated the CCT design. I have not personally replaced the CCT. Having extended warranty is a nice thing.

 

[slowtacotruck]

I bought mine through a Yamaha dealer but with an aftermarket extended warranty. I usually do all my work myself and was a dealership tech for several years so I have a few tools to get it done. I just like to know what kind of shenanigans I'm getting into.

 

[Checkswrecks]

I've heard that a few times. I'm starting to get a little nervous about opening the engine up lol. I've had some engines that the cam and crank gears are not keyed to the shaft and they require timing tools to get the engine into time when you loosen the bolts. Have you replaced the tensioner? Is that pretty easy?

If you worked in a dealer then you'll know how to check and adjust valves in this thing. And opening the engine is no big deal either, as Eric mentioned. It's just that access is really tight between the frame rails, similar to some sport bikes with bike frame rails.

 

[j.bolina]

had your same problem, and generated by the springs of the clutch bell. I replaced with the "clutc bell" of the 2014 model and disappeared completely

 

[ace50]

My bike too developed a rattle (tapping) when I would 'get on it', say above 4-5K.
After a while of doing this and wondering WHAT THE HECK!, I realized I had just put on adjustable bubble side mirrors
and the edge was vibrating against the other mirror at a certain RPM! Re-adjusted mirrors and all was fine!
Engine explosion alleviated!