And even then you'd have to know what kind of pump it originally had. "Most" were Mikuni pumps driven directly off the crankshaft with no other way to control the amount of oil moved through the line(s). Those were dependent on engine RPM only in that at idle it might be 400:1 and on the 7,000 RPM limiter, 40:1.
BUT....
Some also had a cable or a link run to the pump that ran off the carburetor or throttle body. Those ones varied the amount of oil given to the engine by both throttle position AND engine RPM. Yamaha had a few of them that I knew of before I gave up working on ski's. GP1200 comes to mind (1200cc triple). I also knew from factory training that they were around 310:1 at idle and low throttle input and around 55:1 at full throttle/7500 RPM. But if a rider were to back off the throttle to "cruise", the amount of oil given to the motor was significantly less even though the engine RPM was still fairly high. If that link or cable broke going to the oil pump, the pump was set up with a spring that returned it's arm to "full" by default, which sometimes happened, and there was so much oil given to the engine at low speeds that it would blubber. Then the XL1200's came out-with a catalytic converter in the exhaust (kinda like the ETEC's) and the catalyzer was sensitive to too much oil and/or too much fuel. And the wrong kind of oil or fuel. I saw a few of them with MELTED catalysts because of premixing or just owner neglect at times. I don't miss changing the catalysts either.
If ya just premix it at, say, 50:1, should be fine, but it'll likely smoke heavily at lower speeds, if that makes any difference to you.
