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Hi Wadner. Can we have a picture of the whole (broken) crankshaft ? So we can identify that it is GSXR crankshaft. The primary drive gear looks the same on the R1 crankshaft. Please Don't be offended by this request. Some of us might be deciding to change crankshaft to a better stronger one.
A major investment.
 

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from what i understand it is the torque feeding from the rear tire through the transmission to the crank. -

THIS IS NOT NORMAL OR COMMON. that said it has happened and from what i understand in the USA we have not had a single crank failure of a STOCK engine - the key word is stock. so if you have not gone into the motor then dont worry about it.

jason
So, what category would my motor fall into Jason? Stock++??
 

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The only thing I have mounted is the yoshimura Jason kit clutch, I can give you my word that the rest is completely standard.


ok I'll upload photos
 

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l7 6.jpg l7 5.jpg l7 4.jpg l7 3.jpg l7 2.jpg l7 1.jpg l7 7.jpg


Here I leave the images of the two engines with the exact same fault, attached photo of the telemetry just at the moment the engine broke.
broke exactly at 46% throttle and 7603 rpm in second gear

it only occurs to me that the yoshimura clutch has too much engine brake compared to the original system ......
all this is quite frustrating since when it breaks practically nothing can be taken advantage of.

jason the limit of rpm stock
 

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that does suck - the crank completely failed at that point but the crack/s would have started before

you had both failures in the same bike?

thanks
jason
 

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They are two different motorcycles, the first broke with 3800 km the second with 5000, both were equipped with a yoshimura clutch, that's why it is my only suspicion that it could be the reason ......
 

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I have heard of a possible recall. But I also am interested at the failure mileage. Do we know if the proper braking procedure was followed?
 

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the adjustment was correct, but obviously the yoshimura system has much more brake than the standard system, I am confused, it is hard for me to believe that it can break due to strong braking but at the same time it is the only modified part.
 

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I have heard of a possible recall. But I also am interested at the failure mileage. Do we know if the proper braking procedure was followed?
there will not be a recall in the USA... suzuki US has not one reported failure of a stock motorcycle doing it. it would cost millions to do replace the crank. to give you an idea the R1 trans recall of 2017 cost yamaha about 7million.

jason
 

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They are two different motorcycles, the first broke with 3800 km the second with 5000, both were equipped with a yoshimura clutch, that's why it is my only suspicion that it could be the reason ......
Telemetry shows failure on deceleration. So you hypothesize the load, through the rear wheel, from the bike and rider under engine braking, (presuming rider clutch/throttle timing is less than optimal) is higher than under acceleration ? Interesting. I'll have to ask my dyno tuner, of his thoughts on this. The leverage between the crankshaft and the rear wheel being @ 5:1 in both directions. The metal fatigue that occurs is the same as bending a piece of wire, back and forth in your hands until it breaks.
 
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