I've seen threads on this and other forums regarding the newer cast cranks "slipping" and going outside the runout specs, even though the MOCO has gradually increased the max. runout spec to .012", which seems extremely large to me.

But as far as I can tell, it seems to always happen on modded motors, though.

Has anybody had this issue come up on motors that have been left factory stock?

Thanks in advance for any and all input.

 

Most factory stock bikes wouldn't have the need to check the runout. Its only the modded people who go that far into them.

 

There is a local Indy shop that keeps trued & welded cranks in stock because about half the bikes they check are out of spec, or so they say. My '09 is .002 at 28,000miles and getting 103 done. No crank work.

 

Many factory stock bikes are close to tolerance upon assembly. Checking the crank any time the cam chest is opened is highly recommended.

 

Depending on who you talk with, any late model bike could experience scissoring the flywheels. According to reports some of the causes of shifted flywheels have included: wicking the throttle while the rpms are low, a panic stop locking up the wheel without pulling the clutch, a hard down shift, and a number of other things have been attributed with causing the flywheels to shift.

 

I was just stating people who don't modify wouldn't be opening their 2012's. The year the OP referenced. I completely agree inspect any time your working in that area.

 

I think some folks just over think the cast crank / pressed fit assembly thing too far. Could the crank shift, sure. Will the crank shift, maybe. In the mean time I just ride mine like they were built to ride and if the cranks shift (and they might because both of my bikes are hot rods and I ride them hard) I will worry about welding the cranks when apart for repairs.

Too much thought spent on fixing problems that don't exist yet in my opinion.

 

I use the same train of thought. I'll ride it till it gives me a reason to take it apart and check.

 

Thanks to all who have responded so far.

My original question was if anyone with a stock 2012 103 motor has needed to have the crankshaft replaced due to it being out of runout spec. (due to slipping at the crankpin etc.)

Thanks again for posting any personal experiences regarding this.

 

I think the forums and all the discussion has changed things over the years. I've always ridden with the ride it till it gives me a reason, also, but it seems a lot of people are spending a lot of time and money fixing things in anticipation of failure because they heard they were going to fail from somewhere. Kinda like the regulator thing lately, I just talked to a guy over the weekend who changed his even though he was having no problems. He said it was better to be safe now instead of sorry later. Wouldn't it be ironic if his new one wasn't as solid as his old one and failed?