I have a 2011 or 12 900xp. Got it with a grenaded motor but got a spare 2013 motor with it. The spare motor only had 5-6 hrs on a complete rebuild. But ended up with a knock but still ran great when motor was pulled back out. L I tore into the spare motor and it ended up being spun rod bearing. Replaced both rod bearings and put it all back together. Swapped the motors out and had to swap out the stator because the chassis had a different plug than the other motor but I didn’t swap the fly wheels out. At an idle it seems to run good. I have good spark, but as soon as I hit the throttle it starts backfiring. I can still get good Rpms out of it. The mag side cylinder runs way cooler than the pto cylinder. I swapped the pig tales for the mag side injector thinking it could be a fuel problem. And I also swapped the injector out. Both pig tales and injector were used and off the previous motor. Checked the plug wires and the ohms read 7.1 and 7.33. Im at a loss. I am new to these motors and rzrs
Ikrogseng
Double check the valve timing versus both the TDC mark on the flywheel and with a screwdriver in the PTO plug hole to make sure that they agree versus the cam lobes. The TDC mark versus flywheel position on the 2011 and early 2012 XP 900s was at a different position than on the later 2012 and 2013 ones. The early ones used the split in the case pointing towards the rear as the position to identify TDC of the PTO cylinder, while the newer ones use a notch on the case almost totally vertical. If there's a mismatch there will definitely be running problems.
Yeah I used the split on the case for the timing because the virticle tdc made the piston bind up on the exhaust valves on the pto side. What’s the plug on the pto side? I didn’t see anything about that in the manual
To my knowledge, if it's a 2013 engine and flywheel, the PTO TDC position used for setting the cams relative to the flywheel should be the vertical mark rather than the split in the case. The plug hole I was referring to was the spark plug hole on the PTO side. You can pull the plug and set a long screwdriver in the hole and watch it rise and fall with the piston as the flywheel slowly turns. The cams lobes should be in the correct reference position when the screwdriver is at its highest point, although it might take another full revolution to confirm since it may not be on the correct stroke the first time. This is just a rough gauge for the position, though, but can be used to confirm the TDC mark on the flywheel vs. the case.
No I didn’t check the valve clearances cuz it was still running around good (aside from the knock) didn’t figure I would need to. Should I go back and check them is there a reason they could be out of adjustment?
It's not as likely of an issue as the valve timing. However, if you have the valve cover pulled to check the cam lobe positions versus the TDC position on the flywheel and with a screwdriver on the piston, you may as well check the clearances to rule them out.
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
