Oil and Gasoline

Discussion in 'Resources & Links' started by Beretta, Jun 25, 2020.

  1. Beretta

    Beretta Member

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    What is the recommended Oil for the CT's ? I've been using Rotella T-4 20/40 in my Mowers and My Classic 1999 GMC Denali since it went out of warranty- 170,000 on the clock and uses 0 oil. I changed the Oil on my 70 CT and used the same Rotella It has above average ZDDP additives.
    Gas: I've always used NON-Ethanol- 90 Octane in my Mowers for years - I would suspect these vintage 70's Engines would benefit from the same.All of my CT's seem to like it.
    Thoughts ?
     
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  3. airblazer

    airblazer Active Member

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    @Beretta if you search the forum you’ll find a lot of posts/discussions that relatively affirm your stance. The right kind of oil is important when it comes to the clutch, and it takes a lot of riding to burn through a whole tank of non-ethanol. Therefore it’s good to not have ethanol sitting in an idle bike and feeding it with rubber parts.
     
  4. racerx

    racerx Administrator
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    With automotive engines, the Achilles heel, in terms of oil formulation, is the flat tappet cam. ZnDDP-free oil will result in wiping a cam flat. But, flat tappet cams went bye-bye 35 years ago. In a vintage engine with a conventional flat-tappet cam, Rotella is way better than contemporary oil formulations...especially if stiff valve springs and high-velocity lobe profiles are used. But, Rotella is marginal at best, in terms of zinc & phosphorous and it's a diesel oil. The vintage car crowd has been getting mixed results from Rotella, in the last couple of years.

    These engines are very different from automotive engines. The rely on flow volume, not pressure, and the clutch + tranny share crankcase oil. That's a harsh environment and a lot of different oiling requirements. Contaminated clutch discs are not horrible to replace, still a pain. It's the shift forks that are the Achilles heel of these engines. More times than not...far more...shift forks are burned and in need of replacement. Of all repairs, that's the most time-consuming & messy, once an engine is assembled and running.

    You could buy ZnDDP additive, then add it to get back that safety margin. However, Honda GN4, Valvoline & Castrol bike oils, JASO-spec, are proven safe choices. Considering the huge .8L crankcase oil fill capacity, how many quarts of oil is anyone going to run through one of the bikes in a year? IMO, doesn't seem worth the effort to save a buck a quart.

    As for fuel, ethanol-free is best, if you can find it. Once exposed to ethanol, rubber parts swell...then shrink and turn brittle, if allowed to dry. They will bounce back, after a few days of fuel re-exposure...sometimes. Other times, the petcock packing washer must be replaced. These engine will run fine on E10, once the carb has been tweaked to compensate. Unless you source something like "tru fuel" or specialty "storage fuel", which is pricey, no fuel has much of a storage life any more. Even the E0, corn syrup-free flavors contain oxygenates. Thus the entire fuel system should be drained and dry for storage.

    In terms of octane requirement, Honda specified minimum 86. No problem running anything from 87-octane pump regular to 93 octane "premium". Static CR is only 8.8:1.
     
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  5. Gary

    Gary Well-Known Member

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    I always get a laugh out of people who would never put alcohol in their machines but have no problem with drinking in excess. Here in northern Illinois we cannot get non alcohol fuel anywhere. I have to run it in everything -tractors,boats,lawnmowers,bikes,chain saws and weed whips. I use marine stable in everything and have not had serious issues.
     
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  6. Tripod

    Tripod Active Member

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    I just found out that there is a gas statuon a few blocks from me that sells race gas. I think its around 102 octane. Thats not whats important to me, i think its ethanol free, which is rare here in the peoples republic.

    Not sure if the price difference is worth it when i can add stuff to the regular gas.
     
  7. Beretta

    Beretta Member

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    I have 3 Gas Station options for Ethanol free gas- I use Country Mark- 4 miles from me.$ 2.80 a gal @ 90 Octane- usually fill a 55 Gal drum.
    For your area if your interested look here->> https://www.pure-gas.org/
    I have a 55 Gal Drum of C-14 VP Race gas, but I'm reluctant to use it in these Little Engines
     

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