2008 R6 con rod bolts

Hello. I am in process rebuilding my 2008 R6 race bike engine. New pistons, con rods and bearings.
I ordered YEC Kit Pistons and YEC Kit Con Rods. The Kit con rods came from factory with big end halves assembled. The nuts were tightened pretty tight. Turning angle from tightened position to zero tightness were exactly 180 degrees.
Question: Are the new con rod bolts to be reassembled or should those to be discarded because already tightened once?

 

yes new ones for final assembly.

 

In the future a good rule of thumb is if they are torque to yield, replacement is always necessary after being used. Usually TTY bolts are a lower torque followed by a degree rotation for final.

 

Half turn on new, unused bolts sounds like you can use them to me.

 

They're all "tight" from new. Use the bolts and nuts that came with the rods. Torque to stretch, or yield if you have to.

 

I doubt theyd send bolts you cant use....

 

Obviously the bolts were torqued to specs so the big end could be honed and made exactly round.
I am confused because repair manual says never reuse con rod bolts after tightened once to 180 degrees.
I already ordered a new set of bolts and nuts. The rod big ends are most stressed parts in these high revving machines.
Better safe than sorry.

 

Why not contact Yamaha? They would probably have the correct answer for you.

 

Cant remember who discussed it last year but it was suggested to have fresh fasteners for final assembly. Unless you can measure the stretch of the included bolts. And yes Ive seen where "reused" rod bolts failed in short order.

 

Definitely safe than sorry but seems negligent to include bolts unfit for assembly to me.

 

The bolts are tightened to stretch spec so that the big end can be sized properly, as mentioned above. They are one time use bolts. If you want to do it correctly, throw those away or make a necklace out of them.

Best advice: Buy a YEC maintenance kit for the R6. The bolts in there are different, and probably better. They have an indent for a stretch gauge. You get all kinds of good stuff in the kit, including metal MLS gaskets that you can reuse a few times.

 

Thanks RM. I already ordered new bolts and nuts, as i was thinking the bolts are stretched and are not suitable for final assembly. I am seeking for YEC maintenance kit, but there seems none available at the places where i used to order Kit parts.

 

Call Shane at Graves.