Norton 850 Break in time and recommended oil

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Mar 1, 2007
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Hello again. I am getting close to starting my buds 850 after new rings and valves. What oil and grade should I use for break in and how long. Can I get a new filter locally in Texas and what filter should I get. I plan to change to synthetic Mobil 1 15w-50 after break in. I used Hastings rings from MAPP with new guides valves and seals. I drained all oil from the oiltank and crankcase and need to replace the filter. After filling the oil tank with the proper amount should I lift the rear wheel and manually turn the engine over with the plugs out to get oil back in the crankcase before startup or just crank it a lot with the kickstart???? Thanks again--You guys are helping a lot. I wish you had some guitar repair questions as I have been a repairman for over 30 years. All kinds Gibson Martin Fender etc.etc. Muchas- Gracias from Tejas for all the great info.
 

Ron L

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Pour about a cup of oil into the exhaust rocker boxes before starting the first time. This will coat lifters and cam. I usually crank the starter several times to get oil into the crank prior to starting. Watch the oil tank for returning oil. It should start returning oil within the first 30 seconds or so.

I use 40 wt dino oil in my Nortons as the synthetic will seep out the tiniest imperfection in sealing surface and probably wet sump faster as well. If you intend to use synthetic, I would think the 40 wt dino would work well for break-in. I find if I have done a good job on honing the cylinders the rings will bed in within the first 75-100 miles. I change the oil for the first time at 500 miles.
 
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Erm... I don't believe that he was thinking of Commandos when he wrote that. If he was then I think he's bonkers ! That said, if your clearances are in order then rings don't need too long.

That the most important ring seating takes place within twenty miles seems credible but somehow one is supposed to "warm the engine up completely" before riding those twenty miles. A Commando motor with a full oil tank needs pretty well twenty miles before it's at operating temperature.

I think it also needs to be borne in mind that the Commando has a fair old stroke and piston speeds are getting quite high at maximum revs.

I certainly wouldn't consider thrashing a Commando motor until it's done a few miles and had the head re-torqued. Even a "top end" rebuild on a Commando seems to need time to settle before it all feels sweet again.

If everthing feels OK after 100 miles or so then I would let the motor rev if it wants to but avoiding sustained high speed for about five hundred miles.

Well, I'm not an engineer but it works for me and my motors generally feel and sound crisp. I reckon on 25,000 plus miles before a precautionary re-ringing and have never had blow-by problems.
 
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