98' Evo Synthetic Oil question...
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Cruiser
Joined: Jul 2012
Posts: 202
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From: Ajo
98' Evo Synthetic Oil question...
So on m 98' Ultra Classic I have been using Castrol GTX 20-50 for the past 15 years. How safe am I if I want to switch over to synthetic?
I know, it is 2020 and I am still using standard oil on the motor.Change every 3,000
I know, it is 2020 and I am still using standard oil on the motor.Change every 3,000
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Joined: Jan 2019
Posts: 56
Likes: 18
From: Clay township
When I first got my 98 Fatboy I was coming from an 09FLH twin cam and I have been using mobile one 2050 full synthetic. It was noisy and sounded like the oil was very thin. I switched over to what I’ve used for many years Valvoline 2050. Which I used in my 93 and in my 75. The motor sounds much happier. My thinking is when the motor was designed and built synthetic Was not prevalent
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Joined: Feb 2007
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On an older bike with mature gaskets it might be best to stick to regular oil.
It is my understanding that synthetic molecules tend to be more uniform in size.
Since they are more uniform in size then it is easier for them to locate a leak and get in line thus turning it into a drip.
While regular oil will glob at a weak gasket area and maybe weep instead of leak.
It is my understanding that synthetic molecules tend to be more uniform in size.
Since they are more uniform in size then it is easier for them to locate a leak and get in line thus turning it into a drip.
While regular oil will glob at a weak gasket area and maybe weep instead of leak.
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Joined: Nov 2009
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From: Farmington ,MS
I tried syn in my EVO...it did produce a minor leak that could have easily been fixed...I didn't notice any extra noise...
But oil consumption was off the chart...went back to dino...oil use went back to normal...and the leak went away...
But oil consumption was off the chart...went back to dino...oil use went back to normal...and the leak went away...
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Joined: Jun 2007
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From: Bedford UK
Safe? Not a problem, except for the oft repeated risk to gaskets with our old engines. I would also add that none of my V-twins came from the factory with synthetic oils, so I carry on using good ole-fashioned dyno stuff! The exception is my S&S engine, which expressly recommends synth.
The real benefits of synth come with plain bearing engines, modern metallurgy and very precise running clearances, none of which are of concern to most Harley owners. Do the latest Harleys come with synth from the factory?
The real benefits of synth come with plain bearing engines, modern metallurgy and very precise running clearances, none of which are of concern to most Harley owners. Do the latest Harleys come with synth from the factory?
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Cruiser
Joined: Dec 2009
Posts: 156
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From: Tennessee
15-50 Mobil 1
I use 15W-50 Mobil 1 synthetic in everything I own. No issues. It’s thin when needed, thickens with heat and lasts. Vehicles used in are my ‘97 Evo Bad Boy (cammed and exhaust), 02 BMW R1150RT (mostly stock), an ‘05 F150 with a 5.4L V8 (with 230k miles) and a twin turbo ‘09 BMW Z4 (tuned to about 400hp). So a little bit of everything and none of them are babied. No runs, drips or errors. No excessive noise or heat either (which is common with tuned turbos). It’s about $24 a gallon at Walmart.
Last edited by TheVanillaThrilla; Feb 8, 2020 at 08:34 AM.
