| On a KTM forum someone recently posted: " has anyone been having issues with the bottom ends in the 2024 KTM SX125? Mine went at 20 hours from new, I then rebuilt the crank and the bottom end went at 8 hours. Any ideas why this maybe happening?"  I replied: "I think they set the fuel injectors to be lean so they'll pass regulations. That means that the engine will run hot and less oil will go thru it. A too hot engine evaporates off all group 1 mineral oil because its flash point is only around 70C. So I'd recommend any semi-synthetic oil that includes group 2 mineral oil instead of group 1. And I'd multiply your normal fuel oil ratio by 0.75 for more oil, or just run 25/1. Your Penrite oil has around 17% group 1 oil according to its safety data sheet. Most companies lie when they say its fully synthetic. But I'd prefer an oil to also have group 2 mineral oil in it because mineral oil is better for bearings as long as it doesn't flash off. Motul 800 has 6% group 2 oil. To see what oils are in each engine oil go to dragonfly75.com/moto/oil.html and if your oil isn't listed there then just look up its safety data sheet, find the CAS # of any oils listed, and look them up at dragonfly75.com/moto/CAS.html to know their specs and which group of oil they belong to. And here's my video about group 2 mineral oil: https://www.youtube.com/watch?v=lsRa1xeQjS0" Running Hot Fuel injectors make less large fuel droplets than normal carburetors and so that allows the engine to run hotter and the bearings to get less oil because it's the large fuel droplets that cool the engine and deliver oil to all the engine. Proof of this is that fuel injected bikes use one # higher heat range for the spark plug. High heat range #'s of NGK are for hot engines. Click here to read more. Better Oil For injected bikes runing premix I'd look for : 1) an oil with nearly the same density as the one recommended for your injected bike. (.87 for Motorex for KTM's) 2) an oil with the highest % of synthetic or castor oil in it. Maxima Super M and Silkolene Comp 2 Plus are all synthetic oil with a density around .88 (probably due to extra added solvent for pourability), and Klotz BeNOL Racing Castor is all castor oil with .88 density. 3) an oil with little to no group 1 oil in it. |