John,silverstrom wrote:Send them an email and ask them about the cranks. They typically reply in 1 day. I see no difference in the center sections of RZ500 and early TZR250 cranks. The part numbers are different by prefix, 47X vs 1KT. I have both Yamaha cranks here and have never really paid much attention to it.Speed Freak wrote:Hi John,silverstrom wrote: The photos are generic Michael, meaning the same photos are used for multiple listings. It's common practice among vendors. EBay as well.
Did you already see one of the crank webs from Yambits?
If they are not TZR250 webs I would like to buy them and give them to our measurement technican to put it onto the 3D measuring machine.
Also PJME shows a picture of "wrong" crank webs for the 500.
http://www.pjme.co.uk/acatalog/Yamaha_R ... _End_.html" onclick="window.open(this.href);return false;
If you look at the backside (other side than the crank pin) there is a machined ring.
In case of a TZR250 crankshaft this ring is smaller than the diameter of the web, RD500 => ring has the same outer diameter as the crank web.
I think the TZR parts will fit and that`s the reason why they sell it like this.
Would be too expensive to manufacture outer webs for the 500 as there are 3 different types, so they only sell the "recycled" center parts.
For me this is simply wrong...
I think you missed the point of the Yamaha part number system. The prefix denotes the model and thus in most, not all, cases specifies it to be specific to that model. The 10 digit part numbers, (93104-25106-00) are 99.99% of the time generic and used on multiple models. While the prefixed numbers, (47X-15604-01-00), not only describe the part itself but also the model to which it is produced specifically for.
The centers being sold by Yambits for the 500s use a solid pin rather than the hollow pin on the OEM cranks. The flyweights are also cast/forged in a slightly different mold and the machining is also slightly different. They have the correct tolerances to work on the 500 and thus are sold so. However, they are not the same mass for sure. Quality is very good but I am leery of the overall difference the mass and shape may cause with the balance when assembled.