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KTM 560 SMR Motor Problem

10K views 10 replies 5 participants last post by  Throttle_monkey1 
#1 ·
Hey,
I was going to replace stator cover, after removing the cover I did discover few issues shown in pictures attached.
1. Home made looking weld around the crank case bearing, right on the block. Have you seen anything like this? Maybe it done because previous crack in the case? Maybe it was done to strength it?
2. Flywheel is rubbing onto the stator creating minor metal shavings.
3. Mechanic measured wobble of the crank shaft, it is 0.0005 of an inch. He did not move shaft to see if bearing is out and put it all back together.

Let me know if it looks like someone was trying to quick fix case avoiding big expense or it was done to make case stronger.

Thanks:bowdown:
 

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#2 ·
The 560 has an issue with spinning the crank, I race at Loudon NH and every one that has a 560 has had the crank welded. the problem is KTM used a 450 crank on the 525 and the 560. the 525 has had some problems but the 560 spins almost all of them. im wondering if somone knew this but had no idea what welding the crank meant and did that, or they spun it messed the crank bearing up and it leaked and thats what its for. Dont know if this helps < Adam
 
#8 ·
BS.....BS, BS.

ALL three cranks are different part #'s and different in WEIGHT. All RFS motors use the same DESIGN but they DO NOT USE THE SAME CRANKS. Just look up the part # yourself and find out, ALL three use a different stroke length and also have different crank side halves.

The real problems arrive when you have that big a piston and not enough end play to start with. At high RPM the crank begins to flex and this in turn moves the crank pins out of true with the center/rod pin. Some were so tight the crank hit the cases, while others only took out the crank bearing and ruined the crank outer pins. Yes the 560 from the factory uses a ball style bearing on the left, and a roller on the right like most other 250/400/450/525 RFS motors. The ball bearing helps to handle the side loading but does not have the durability of the roller. Therefore 560's need crank bearings at a much lower HOUR run time than the other engine sizes. yes welding and truing the 560 crank helps with this issue, but once it slips and goes away even welding and truing an already spun crank is NOT a true fix-all...the 560's eat crank bearings, and all of this depends on how hard you ride it and on what type of surface as well. Good luck
 
#3 ·
If crank shaft is bent, will I have to buy a new one or can I remove existing one and have it welded? How much does it cost to weld it and who does it? If case is busted, I guess I would have to replace that also while motor is disassembled.
Do you have any pictures or instructions of crank shaft welding process?
Thanks for your help.
 
#5 ·
I'm a new 560 owner and I don't think my crank has been welded. What part of it do they weld, and what is accomplished by welding it. Should I go through all the work to tear down the whole motor to have this done? Is it critical?

Is the crank undersize on the bearing journals?

Sorry for all the questions, but I'm just trying to figure out what this welding does to the crank.
 
#9 ·
Is the roller bearing that is used a straight roller or tapered roller bearing?

I guess I bought a lemon. How long do these bearings last? I don't really ride around at high rpm, I like to short shift it, and don't race, just ride on the street.

Will I be needing to replace these bearings every couple of months, even with ball bearings?
 
#10 ·
It is a straight roller. Like stated earlier welding helps the crank and there are different quality of bearings, but looks to me like someone already had a problem and lost a crank and it was not completely repaired properly. Looks like a weld job on the case webbings was done poorly and did not hold, might be time for a new set of cases and a NEW crank. RFS motors like yours on the street last approx 100hrs, but like I said it depends on how you ride it.
 
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