800 Outlander dropped valve

[Fyko 0]

I have an Outlander 800 XT with 480 hours on it. Very recently the engine power dropped significantly while riding. Soon thereafter the engine created much noise and stopped.

On opening the rear cylinder I found one inlet valve stem bent and the other broken. The valve head caused considerable damage inside the cylinder.

My reading is that the timing chain to the rear cylinder jumped at least one sprocket tooth to reduce the engine power, thereby compromising engine power, and then shortly thereafter jumped one or more teeth to allow the rear piston to contact the intake valves. On disassembly I did not notice that the timing chain was particularly slack, but neither  was I looking for such things. The ATV has been serviced by agents according to requirements, in fact it was serviced very recently, by accredited agents.

Coincidently I met another 800 XT owner a couple of days ago who had had a similar incident a few years ago, which makes it likely that there are others out there who have had similar experiences. If there are I'd very much like to hear from you.

[Frank Angerano 835]

Hey @Fyko welcome to Quadcrazy. That really stinks man about loosing the valve. Was the piston damaged? Also have you looked at the timing chain tensioner to see if anything was going on there ? Also maybe just a stretched timing chain? 

I would also check the other cylinder as well if your going to tare into it. Never know.  

Good luck brother 

 

[Fyko 0]

Hi Frank,

Good to hear from you. And good questions you have.

Right now I'm in the boonies of Mozambique, which is about as third-world as you'll find on the planet. So I haven't opened the front cylinder yet, but definitely will for the reasons you mentioned. Before we took the head off we didn't look too closely at the state of the tensioner because we didn't know what we were going to find under the cylinder head, and now it's a bit too late. But very good point. Thanks.

I spent the last 60 of my 69 years taking engines apart, but with this machine I gave it to the agents, so I have to trust they'd check such stuff - until proven otherwise. Having said that I must tell you the state of general workshop diligence here is so low that it's easy to picture them spending more time writing the invoice than doing the actual work.

Another thing I need to mention is that parts to fix this thing i.e. rear cylinder head, piston, and gaskets would cost US$564 from PartShark in the US. Plus postage. BRP hatched a plot with the local (South African) agents of BRP to disallow sales of parts outside of the US by US dealers. The same parts I detailed above cost well over US$2000 here. Now that really sucks.

The piston was pretty battered but not penetrated, the head was hammered from below, but can probably be rendered usable, the two intake valves are obviously shot. The minimum to repair will be a piston and 2 valves - and then most likely 2 timing chains, since it's hard to imagine them jumping sprocket teeth without being severely stretched.

Thanks again for your comments.

Best regards

Fyko

[davefrombc 353]

Do you know anyone in the  US you  can trust to pick up  the  parts and  ship them  to  you?  I looked for Canadian dealers  but BRP  must have the same deal  with them . No shipping outside Canada  even to  the  US, and  I  didn't  find any  that  showed pistons or heads available online.

[Fyko 0]

Hi Dave, Sadly no. I should have distant relatives there, but too distant to lean on in this way.

I started this thread fully expecting others to have come up with this problem somewhere, on the basis that two near neighbors in South Africa have this disaster strike and not anybody else. But so far it's just the two of us - though the agent was heard to mutter darkly about how these Rotax engines regularly drop valves.

I'm now thinking that the front timing chain will probably turn out to be stretched as well. And it will come back to the servicemen not checking this when they ought to, this being Africa remember, where anything goes.

We won't know anything more until the ATV is trailered back home and we open up the front cylinder. But it's starting to look like shoddy local maintenance.

Thanks, and best regards,

 

Fyko