Decreased engine life with premix?

I’ve been riding skis converted to premix for years and never thought anything of it, but I just read on a snowmobile forum that converting a premix race sled to oil injection increases engine life because it’s easier on the bottom end? Is this true, and if so why does everybody convert skis to premix?
 
factory oil injections dump way more oil in the motor than most guys mix with their gas. more oil means better lube and extended life. if you ever noticed, old 440s were supposed to get a 20:1 oil mix in cold weather. nobody mixes that ratio in anything these days. ever notice how older skis smoke like an SOB with stock injection still working? stock injection provides more oil. more oil usually decreases performance and that's the main reason new performance stuff is 40:1
 

Zero Client

BeerrroooOOOT!!!
Location
Douglasville, GA
Lucas additives for the win.

Seriously, a working oil metering pump is a bit dynamic - at idle and low RPM - it could be mixing oil at 100:1. At full throttle; it could be pushing more like 24:1.

What I do to fix the whole problem is carefully remove the precision oil pump as to not disturb it and make a royal mess of things inside my hull. I then carefully take the pump and, while standing, lower it to the ground between my feet with both hands cupping it so that it does not accidentally fall to the ground and get all dirty. I then lift upwards with all my might (Spinach helps) while a friend bird-watches the pump as it flys as high as I can throw it (Limited by gravity and physics of course). Take a measuring tape and measure how far it gets thrown and write that down in my jetski notebook for later use.

Then I take my trusty $2 ratio-rite from Walmart and add 40:1 mix of Klotz R50 to my gas cans.

Works every time.
 
Sled motors now days have fairly sophisticated oil pumps that put oil in strategic locations. Running premix in those can be an issue, especially the motors that have a central shaft between the cylinders that runs the water pump on the front of the motor. The two stroke motors found in stand up skis are pretty crude, and they have crude oil injection systems that just pump oil into the intake someplace. Running them on premix is fine. The points about oil injectors varying oil flow with load are somewhat valid, but keep in mind that snowmobile motors make about double the power of a watercraft motor in stock form and at much higher rpm. Stock ski motors are really quite mild and crude.
 
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