Almost had an engine failure! Watch out guys!

A couple weeks ago... I shut the sled off after a ride, so the engine was warm. 10 mins later I go to start it and it was very hard to start, i had to hold the throttle at 1/4 to get it to fire up. But the sled didn't sound right, it didn't have enough power to move and wouldn't stay idling without a bit of throttle.

I trucked the sled home and put it in the garage. Impatient to wait till Monday for my dealer to open, I had a look at it myself, checking the simple and obvious.

Checked the plugs and compression (what a task BTW!) Everything checked out ok.

I then pulled the airbox cover off and knew what happened right away. One of the two little metal clips that holds the air filter in was missing! (The rivit cracked off, possibly due to vibration).

Well... there's only one place this metal clip could have went... down the intake. So I pulled the throttle body off and had a look, sure enough, there it was jamming one of the intake valves open.

I hooked it out, put the sled back together, and it seemed to idle and run good, lots of power, back to normal.

I also dispossed of the other metal clip before it finds its way into the engine too.

I havn't made it to the dealer yet but I am gonna have them take a look because there are two things that are bothering me:

- how can the intake valve stay open and the piston reach TDC without doing damage? I didn't think there was enough clearance?

- and the clip was chewed up pretty bad so what about the valve seats? It wouldn't hurt to have a look at those too.

The ODO said 320kms when this happened, the sled is parked untill my dealer has a look at it. So just giving you guys and gals a heads up, possible recall?

Here's a pic:

Holy crap. That's totally believable.

I was messing around with those exact clips tonight on my airbox cause i had the filter out to clean it all up, and those clips seemed loose on mine, enough that they weren't even doing anything to hold the filter cover on. Yikes!

One fellow in my area had the same thing happen to his machine. That same clip came off and got sucked into the engine. Yamaha replaced his motor I was told. Topper

Think you were saying that you have measured the compression? Sounds really strange that it was the same on both cylinders if one of them had a open intake valve..

Also, I have seen something like this once before. It was on a dirtbike (wr) but on this we had to take of head, out with valve and rebuildt because valve and seat was dammaged. Btw, bike seems to run ok before it was repaired but it had loss in compression.

Something to certainly to check out, thanks for the heads-up!

sniperviper said:

Think you were saying that you have measured the compression? Sounds really strange that it was the same on both cylinders if one of them had a open intake valve..

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Sorry I screwed that up I did'nt check the compression, I was going to but my gauge was busted, but you're right, should have been 0 psi on that cylinder. I have to get a new gauge and check the compression, this should tell me if the valve is seating.

I see. Hope that everything is okay. Last time I inspected my air filter I noticed that one of the clips was loose but still in place. Will check it out before next time I start it up.

If yamaha know about several phazer's this have happened to I think it's strange that they havent stated a service bulletin on this issue. Think it would be much cheeper to recall sleds for check than changing a lot of engines before taking this seriously.

Thank you for letting us know!

I got looking around my today and everything is good and tight! Got thinking about a fail safe idea! Put some zip ties or rubber band on them there clips and secure them to something, in case they do decide to vacate the air box! Until a guy can dream up a better idea! Just a thought!

Word

I put some silicone on mine to dampen any vibes and hold them in place

Couldn't find any good way to tie them up so I pried them out with a screwdriver
then cleaned up/sealed the holes with a soldering iron. No worries.

Why the heck the backfire screen just could of clipped in all the way around like it does in the front is beyond me! The thought of little things that can get sucked into the throttle bodies gets a guy a little paranoid! Rfabro, with out them clips, does it still seal up o.k?

Just fine. It's really all about the foam filter underneath anyways.

Been in the airbox a few times but having trouble visualizing what you guys are talking about. Are you talking about the metal clips that hold the metal screen down (which contains the foam filter)?

If not can someone take a pic?

Thx,

-Steve

BV1 said:

Been in the airbox a few times but having trouble visualizing what you guys are talking about. Are you talking about the metal clips that hold the metal screen down (which contains the foam filter)?

If not can someone take a pic?

Thx,

-Steve

Click to expand...

You have it right.