KT 100 rods
- Thread starter rainman
- Start date
Ted Hamilton
Helmet Painter / Racer
paging Mr. @Pete_Muller ...
Pete_Muller
Moderator
I'm pretty sure that it's an identifier of the forging die used for that particular rod.
If you can ever find one, the "X" rods (from back in the late 70's) were the best of the best, in my opinion. Finding one that isn't worn out would be little running across a unicorn, but you never know!
I believe that the "early" con-rods from Yamaha were made from better material. They are definitely considered "light" rods, but I never had the big-end go out of round on one of those early rods, even in my direct-drive Yamaha that regularly turned 17,000. When Yamaha change the forgings slightly to make the "beefier" looking rod, I believe they used material that was not as good (cost savings?).
To add one other piece of information (that you didn't ask for, haha), shoot for about .0013" clearance on the big end, and .0009"/.0010" on the small end. That seems to be what works best for performance.
PM
If you can ever find one, the "X" rods (from back in the late 70's) were the best of the best, in my opinion. Finding one that isn't worn out would be little running across a unicorn, but you never know!
I believe that the "early" con-rods from Yamaha were made from better material. They are definitely considered "light" rods, but I never had the big-end go out of round on one of those early rods, even in my direct-drive Yamaha that regularly turned 17,000. When Yamaha change the forgings slightly to make the "beefier" looking rod, I believe they used material that was not as good (cost savings?).
To add one other piece of information (that you didn't ask for, haha), shoot for about .0013" clearance on the big end, and .0009"/.0010" on the small end. That seems to be what works best for performance.
PM
Pete_Muller
Moderator
I'm not aware of any that currently exist.
rainman
Member
Thanks a lot.
Pete_Muller
Moderator
Any time rainman!
On the off chance that "best Yamaha cases" might interest you, I've had this article online for... probably 20+ years:
http://www.muller.net/tech/docs/casenum.html
PM
On the off chance that "best Yamaha cases" might interest you, I've had this article online for... probably 20+ years:
http://www.muller.net/tech/docs/casenum.html
PM
rainman
Member
Excellent article. Some of that info makes complete sense for some issues I have experienced with the die cast type. I think I might even have one of the oldest type. Appreciate the info. Do you know anything about the 90s PCR reeds? I have 2 TSL 98s, a 95, a 93 and an older one.
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Pete_Muller
Moderator
rainman,
I'm sorry, but don't know much about that series of engines. I vaguely recall that I may have blueprinted a few sets of those cases for someone many years ago, but that's the extent of what I can remember.
PM
I'm sorry, but don't know much about that series of engines. I vaguely recall that I may have blueprinted a few sets of those cases for someone many years ago, but that's the extent of what I can remember.
PM