Yamaha Limited Pipe Specifications
By Lynn Haddock
The approved RLV PIPES for the Yamaha Limited Class (#17) are the VKA-K1, VKA-K2 and the VKA-SR-Y.
These are the same pipes as the older model KPV K1 and K2 and the WKA/IKF SR-Y. These are readily available in the used market.
The current RLV HEADERS are the VKA-9110 (12 degrees) and the VKA-9110 (straight). However, any straight tube header may also be used. No tapered tube headers are allowed!
The minimum length for all the pipes is 12″ from the piston face to the start of the first cone. For convenience, the edge of the fin just above the exhaust (see Fig. 1, below) is 2.4″ from the piston.
FOR THE 90° PIPE
For the 90° models (K1+K2), this means, in order to have a minimum distance from the piston face to the end of the connector tube as 12″, the connector dimension has a combination of 2.4” + 9.6” = 12″ (see Fig. 2, below).
FOR THE 60°/30° PIPE
Unlike the 90° model, the 60°/30° model has 2.5″ of distance is made into the 60°/30° elbow (see Fig. 3), so the distance from the piston to the end of the connector tube is 9.5″ (2.4″ + 7.1″) minimum (see Fig. 4) and the overall minimum distance is 12″ (2.4″ + 7.1″ + 2.5″ = 12″).
There is no maximum length for any header. The connector tube is 1.750″ diameter.
For information on the RLV pipes go to: www.RLVcatelog.com. On the left, at the bottom, click on VKA Vintage Pipes. This page with the 90° and 60°/30° pipes will come up.
RLV PIPE CLARIFICATION BY LYNN HADDOCK
Several questions have arisen regarding the RLV pipe and the proper installation. Below is a picture of the 90° pipe (Fig. A) and the correct, minimum length of the connector tube (Fig. B)
Fig. C shows the 60°/30° pipe, and Fig. D shows the proper installation of the minimum connector tube.