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'13 800 Pro running rough

L
Nov 13, 2012
66
15
8
Waverly, MN
After a long pull yesterday my Pro started running like it was only on one cylinder if you blipped the throttle 10 times it would clear up run top notch. But if you let off the throttle and it got below 6000 it would run rough again. It did run out of gas the other day so I thought maybe dirt in filter, brought to dealer in town and they said it was PTO but both cylinders are dead even at 100psi cold, and 105psi both after running a few minutes I know thats a little lower than it should be. But would it run perfect at 6500-8200 if it was a bad cylinder? It didn't throw a check engine while it was a running rough. Any help would be appreciated.
Thanks
 
X

xc6rider

Well-known member
Jan 12, 2009
1,484
484
83
Iowa
How'd the plugs look? See the piston domes at all?

Id prob start with pulling, cleaning, inspecting exhaust valves. And youll be able to get a little look at the exhaust side of pistons.
 
X

xc6rider

Well-known member
Jan 12, 2009
1,484
484
83
Iowa
Cant see what the markings are clear enough...

Could be a piece of ring, or a ring locating pin, piece of crank bearing etc... If it is something thats been bounced around in the cylinder. Does the head look the same?


Pull the cylinder and see what everything else looks like
 

Scott

Scott Stiegler
Staff member
Lifetime Membership
Nov 1, 1998
69,618
11,737
113
51
W Mont
Something definitely went through there.


Maybe rings.


You never know.


I had a nut go through my cylinder and it kept on ticking. It was unbelievable.
Rode it the rest of the day and it did just fine.
Had a little head damage and I replaced the piston, but we cleaned the up and she was good to go.


It was a nut from a nitrous nozzle in the air pod filter.


Good thing for BIG displacement in the 1155cc twin.


I got really lucky, because I was a LONG ways in the backcountry.
 
X

xc6rider

Well-known member
Jan 12, 2009
1,484
484
83
Iowa
Looks like a ring locator. Can you see if both of them are still in the piston?
 

Scott

Scott Stiegler
Staff member
Lifetime Membership
Nov 1, 1998
69,618
11,737
113
51
W Mont
I'm not seeing much piston wash....
attachment.php
 
B

BC_mtn_rider

Well-known member
Nov 11, 2012
160
66
28
48
Surrey B.C.
looks like your missing the green injector o ring on the left side in the pic. don't drop that sucker down into the crank
 
L
Nov 13, 2012
66
15
8
Waverly, MN
When all was said and done its seems as though part of the cylinder wall/skirt broke off, you could see the exact shape where it broke off as to what was hammered in the head and piston. The reeds on the PTO side were good so nothing was sucked in. Rod bearings were tight and there was no bottom end damage. Put reman mono block and piston in it and bolted it back together. Being that was motor #2 to fail in 1350 miles, I hope my new AXYS treats me better
 
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