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Oil for 503

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keithkrum

Active Member
Joined
Dec 17, 2021
Messages
41
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Were not talking about Gasoline Flashpoints or Car Oils conventional or Synthetics 300F-495F, were talking 2 Stroke Oils! Ask Rotax Rick if he gets 450 hrs without a Decarbon using that "Quicksilver PWC Oil with a flashpoint of 149F degrees or the Amsoil Interceptor Oil Flashpoint of 183F". The bottom end of your 2 Stroke engine normally shouldn't see 200F per the Rotax Engine Head Manager I talked too at Oshkosh. So I asked him then Why are many of these Rotax's have Bearing Problems? His comment was the Oil used and Octane Gas used. I will guarantee you the bottom of that Piston Dome is Hotter than 200F. Those Pistons that are Seizing Melting on your Cylinder Walls is way Higher than 200F. Aluminum melts at 1220F. I have seen PTO Bearings with the Black Plastic Retainers Melt which takes 375F to melt that Black Plastic usually caused by people over-tightening their Belt Drives. Nylon Bearing Retainers are good till 500F and don't rust (what Rotax Rick uses). Rotax Rick is Old School, a great guy, he has to see Oil dripping off all the parts when he takes an Engine apart.

You need to Read up on 2 Stroke Oil Flash Point Testing. I'm sure Wikipedia has built a lot of 2 Stroke Engines. What was once recommended years ago, today is a different matter. Hirth recommends today their Blue Max Oil at 100:1, Skidoo/Rotax recommends their XPS BRP/Castrol = 350F, Yamaha recommends using their Yamalube = 255°F.

These Top (6) Oils are High-End Racing Oils usually expensive. I don't know anything about them, never tried any of them. Most Sled Racers I have talked to like Klotz Oils. I was using the #7 XPS BRP/Castrol = 350F in my 670 in a Sled with No Problems. I have been using Amsoil Saber Pro at 100:1 in my 1972 292 TNT Skidoo Single, so far with no problems.


1. Klotz R50 = 550F
2. Klotz Benol = 550F
3. Motul 800 = 485F
4. Castor Oil 2 Stroke = 445F
5. Bel Ray H1R = 435F
6. Maxima Castor 927 = 420F

Post off a Chainsaw Group. It also depends on how the flashpoint was obtained, open cup vs closed cup. Often times the flashpoint simply indicates the volume of solvents, as they off-gas and ignite long before the oil ever will. Oils like Yamalube, Amsoil Dominator have low flashpoints, but they offer good protection. Application of the oil plays into it as well, chainsaws has a very low output for the displacement that they have, which is why the thin low film strength oils work well enough in saws and other O P E. That said flashpoint does have some relevance "especially when obtained in the open cup method" and often goes hand in hand with higher film strength oils like R50 and Motul-800. The two best oils that I have used in chainsaws thus far are K2 and Honda HP2. Motul 710 is promising, but I haven't used it much. For Racing, most use Klotz Original Techniplate, or Maxima 927 which has Castor in it. For milling I like the thicker oils like Motul-800 and Klotz-R50, but really K2 or HP2 would be fine in this application too.

To my knowledge, these are all Open Cup Flashpoints.

As a newby with Rotax engines, I have been trying to figure out which oil is best for my 503. the Amsoil Saber Pro is one that I am seriously considering. But for this engine, it would be at 50:1. Nay thoughts on that application?
 
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