HELP!! Strange engine noise in Apex

[rock doc]

I am getting a little freaked out. At the end of last season, the engine would make a rattling noise when it idled down once warmed up. I was sure it was an exhaust leak, so I didn't get to excited.

So I stripped the sled down to complete the oil change. I decided to check for leaks by blocking the exhaust while running. To my surprise, the sled stalled. I could not find any obvious exhuast leaks.

The engine has approx. 2200miles on it. It is a 2006 APEX. It doesn't burn oil and seems to run smoothly. Is there a heat shield or something that could be loose?

Any advice would be appreaciated!!!!

 

[Len Todd]

Take a look at all parts under the tunnel. The Tunnel Protectors rattled on mine. Also, the heat shields work loose and rattle. Sometimes the cross-over for the Heat Exchangers rattles too.

Also, if your idle falls below 1500 RPMs, the clutch and reduction gears can rattle.

 

[shawnj]

Exhaust donuts/flanges, possibly. I hear they loosen and need to be tightend sometimes. If they go on and rattle loose they will wear the pipe or mainifold, not sure I got the termonology correct and then be expensive to repair. Yamaha mechanice was working on this one day I was in and was explaining and showing me this. Not sure if that is where your noise is coming from but better to check it.

 

[Len Todd]

With only 2200 miles, it is a little early for exhaust donuts. But, if you get backfiring when you let off on the throttle, then maybe exhaust donuts. But, you did say you checked for exhaust leaks. So, ... What did you find, so far?

 

[bottlerocket]

I had a bad clamp/donut that rattled at idle. The sled stalled when I covered the tips so that test is not to trusting.

 

[Len Todd]

You may have to remove a little metal between the two clamp halves where the bolt passes through to allow it to clamp a little tighter. I took about 1/8" out and the clamps were all fitting nice and tight on mine.

 

[unclearpine]

I had the tunnel protectors rattle on my apex at idle I put a drop of silicone on it.The other thing that will rattle is the primary clutch ,this is something that is a common rattle on all yamaha sleds ,if its not that then is it the exhaust donut clamp rattling against the shield .I hate rattles.

 

[bottlerocket]

You should be glad General Motors doesnt make sleds....

 

[Len Todd]

My tunnel protectors were rattling' this year also. I pulled a thin insulated wire around the fastener and then twisted it to take up the space between the protector and its mount. Next time I get in under the muffler, I'll fix it right, ... maybe.

 

[rock doc]

Thanks for the input guys.

To be honest this experience has turned me off snowmobiling for a while. I am really really really tired of wrenching on it. I have a nice heated garage with lots of tools etc. I just have spent way too much time working on this thing. Here is the list:

1) wire pulled out of shock 1st time out. Drop skid and fix;. Install Big Boy to fix bottoming. Install new skis to fix handling. Install rear cooler to fix over heating. Install a real windshield, Install bushguards cause my hands almost froze solid. Hyfax wear is outta this world.
2) wire pulled out of top of shock this time. No cheap fix so I leave it.
3) Bottom transfer rod pulled apart. Got ticked off and dropped a ZX-2 in her


I'm sure you are all laughing at the list becuase it seems like everyone has been there and bought the shirt. That is what ticks me off the most...I think Yami should have come good on at least some of this (the wire, handgrips and cooler for sure).

All this in 2500 miles. Last year I barely went out because we had another wee one. There are no miles on the thing.

Don't get me wrong, I love the sled. I guess I'm just a little down cause once again I'm grounded with problems and the season is here. The guys are saying this is the most over serviced sled in history. I even got a flippin lift for it cause it seemed like I was working on it soo much. I guess I'm mostly disappointed because I have owned lots fo Yami hardware and have always had really good luck. The road version of this sled has been great to me.

Anyway...thanks for listening and offering advice. I'll get over it and continue taking bits off her tomorrow. Can someone point me to a good link for getting to the Y-pipe? I dunno what I would do without this site, it truely rocks

 

[rock doc]

Found a good link.
http://www.ty4stroke.com/viewtopic.php? ... ight=ypipe
Thank God for TY!!

 

[w8tn4snow]

I started hearing a weird #*$&@ noise from the first ride on my Apex . Couldnt narrow it down it seemed to get louder the faster i rode then would go away if i stopped . Mechanics couldnt find it , freinds rode it and never heard it . I took a tape recorder out with me one day to prove to my freinds i wasnt crazy and there was a noise .

....Turns out i was crazy , it was me giggling , woohooing and laughing to myself the whole time !! hehehe
Sorry dude the voices in my head made me do it !