- Mon Aug 26, 2019 12:08 pm
#85097
A mate of mine who even runs pre-war stuff reckons it doesn't cost any more to fix a head with valve recession than to modify it to take unleaded. The fix is exactly the same (fit a hardened seat) so he just keeps an eye on the valve clearance. Apparently some are totally fine, others have problems and he has them done.
I have heard tales of some of the phosphate lead replacement additives producing quite tenaceous deposits in the top-end.
Ethanol is another matter. I've even had japanese bikes suffer from problems with ethanol. One actually caught fire when I was riding it because of ethanol corrosion causing a needle valve to stick open! Luckily it self-extinguished leaving a large hole metled in the airbox.
My VFR750 is a 1991 bike and it's not designed for ethanol fuels either, it attacks the fuel lines, fuel pump and carb internals.
As such, I'm using frost automotives anti ethanol additive "Ethomix" in it. Especially when it Europe where E5 is standard and E10 is usually placed next to it. It's also a fuel stabiliser so parking it up with a full tank of stabilised fuel overwinter is my go-to strategy. Unstabilised ethanol fuel will tend to split over time, leaving you with a layer of rusty water at the bottom of your tank.
What I would do at a minimum for your own safety is make sure the fuel line is ethanol safe. I fitted a piece of old (but unused, stored in a jiffy bag inside) fuel line on my 350 bullet and it went like playdough. Broke off under the clip while parked up overnight after the first ride. Luckily I turned the fuel off or it would have been all over the garage floor!
Fortunately for enfield owners, there are fewer complex parts ethanol would damage and most are in the carb. Most are amals and they are still making them new in an ethanol-proof form. So if you have an issue, it's easily fixed.
Octane boost? I get pinking on my 612 bullet if I use standard unleaded so I've started carrying a shot of octane booster. On the advice of friends who are running highly stressed, race-tuned, japanese endurance bikes competatively, I've been using Royal Purple octane boost.