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Just bought my daughter an 07 Outlaw 525 IRS. I've read about the 525 KTM engine being noisy (not sure why, but they weren't lying! 馃槃). I have determined that the noise reduces when I pull in the clutch. Is this typical, or a sign of something needing to be addressed?
Thanks!
 

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Yes, it needs to be determined if you have a vibration coming from the chassis which is common with skid plates and nerf bars on mine (routine tightening upkeep is needed). There can be cam chain issues and valve clearance out of spec. that will present a noisy condition also. I checked all this prior to moving the crank primary gear nut, it is actually pretty common issue with this engine. That vibration noise is loud everywhere in the front of the engine (top/bottom/front), so it's hard to really identify externally.
In this case you need to drop the engine oil and pull the clutch-side engine cover off, not just the clutch access cover, the larger one that has 10 allen bolts. The crank nut needs inspected, it has a large aluminum nut that will back off if it this has not been addressed properly. I dealt with this on mine and did a bunch of reading online to get the nerve up to buy the gasket (ebay), and get into this chore, which was not all that bad really. My crank nut came loose by putting the big 2Xmm (sorry forget size, I think 25mm but don't rely on that), and spinning it with my fingers (no ratchet involved). That is apparently a common issue. This nut is supposed to be torqued to 110 ft. lbs. and it is LEFT-HAND THREADS ! The nut is stamped with indication of that as well. I cleaned the heck out of the threads on crank shaft end threads and nut, then I applied orange Loctite (manual spec. = Loctite 243), and tried to torque mine to spec, not the KTM / Polaris recommended (Polaris part#: PA-48685) Clutch Holding Tool. I didn't have want to buy the tool, I wedged a rag in the primary gear assy. that I felt would lodge the crank from spinning. It was not optimal for the torque wrench hold, so I went with plan B and it's probably not a great idea and used my (Earthquake 1/2" high torque) impact gingerly, about 4 blips. Let the Loctite dry/setup completely (mine: overnight) before replacing the engine cover and filling with oil. I bought a new gasket before doing the project, I used a quality name brand (Vertex I think) gasket, OEM is pricey and does not like to be re-used. Clean all the gasket surfaces meticulously before installing new one. Note: engine at TDC is not necessary for this, but probably should start with doing the valves first and that does require putting crank at TDC.

Since doing all this and about 29 hours on the quad, it has been back apart for re-checking, and reassembled using that same gasket, and ran. That inspection was not because I am that anal, it was because I jumped the gun and thought my first go was not enough torque applied and it backed off, but in fact is was just the front A-Arm skid plates vibration making the same noise due to foam tape breaking down. There were/are no problems whatsoever at the crank still.
The first 10-12 hrs. after this fix were hard dunes riding, lots of hammer down runs on the sand drag strip, and 3rd-5th gear wheelies pinned across the dunes. The other 8 hrs were WV trails and hillclimbs, some power put to the ground in many situations and held strong. Long-story short, that fix is solid. There is a ton of info out there in the interwebs on this issue too search "KTM RFS engine crank primary gear nut loose".
Have your 2 new oil filters (short & tall) on hand and correct engine oil on hand for this task as well, be sure your clean both the oil screen filters for materials, especially with the loose crank nut condition (side case / bottom case). However, that is routine maintenance anyway.

I am adding some manual snippets of that proper crank hold situation.
The clutch holder tool is in first snippet, it may be a good option for holding primary gear for torque down procedure, but I am not a KTM / Polaris tech., just take my fair bit of mech. aptitude, do some homework, and then run with scissors.
The KTM525 engine is absolutely amazing with the IRS setup, it's hands down the best quad I have ever ridden in my 40 yrs. of riding. Make sure the power is fully respected, it is a real deal performer with controllable power.

Also based on your indication that clutch engagement makes a difference on noise. There are some other posts on the interwebs about clutch basket vibration noise that comes from the bearing (if I recall correctly), but still could be the primary nut. I did not find slop in my clutch basket. A little reading goes a long way with the tail chasing and saving $$$$ from just taking it to a shop.

Good luck with resolving the noise!
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Just bought my daughter an 07 Outlaw 525 IRS. I've read about the 525 KTM engine being noisy (not sure why, but they weren't lying! 馃槃). I have determined that the noise reduces when I pull in the clutch. Is this typical, or a sign of something needing to be addressed?
Thanks!
 
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