Gasoline questions ??
 

From what I gather the compression on the Brozz 250, that I expect to receive in a couple days, is 9-1 . I don't know if 93 octane will offer any power,or anti- knock advantage over 91 octane, but no more fuel than these bikes could consume ,I will probably run 93. My main question is concerning alcohol content of fuel. I know these Chinese bikes come with a smaller than ideal main jet, and I know from some experience with racing that an engine will consume twice as much fuel on alcohol as on gas, and the carb has to be jetted according. If nothing has changed in the last few years we have one gas station that offers pure gas. Will these bikes in stock tune normally run better with gas that has no alcohol. Do any of you mix your own octane booster / fuel recipe?

These engines will run on 87 regular all day. No need to run premium. The only reason people avoid the E10 regular is because it can cause oxidation issues with the carbs. A bit of stabil marine or MMO in the fuel helps a lot with fighting issues like that, lubes the carb parts, and keeps the tank rust proofed from moisture. Just drain the bowl when the bike is going to sit.

I run at least 91 since getting the head ported, but since it's not been decked im guessing its probably not needed and 87 would be fine, in either case I dont mind spending the extra 50 cents or so to fill.
And since i ride year round with usually no longer than 2-3 weeks of downtime when it gets too cold or icy out, I don't worry about carb getting gummed up as ive read the gas will usually last at least one month.
Now for all my other small engines, ie, mower, weed whacker, chainsaw, etc, I always use Startron Enzyme treatment and it claims to keep the gas fresh for up to 2 years, never have had an issue in many years.

My bike is up near 10.5:1 compression and has a 4 degree timing key AND an adjustable CDI, and I am fairly sure 91 isn't needed on my bike until the outdoor temps get up on the high end of the scale. I just run it to be safe. Before the key and CDI I actually ran it on 87 with the higher compression without any issues, so yeah, you are probably just fine lol.

I run mine on premium just because it's only $7.00 to fill it up from empty.
They also run on premium 50/50 mixed with two stroke oil, but poorly, lol. I accidentally found that out when I topped it up with mix intended for my boat.. it was only a little while before I realized it and drained the bike's tank out.
MegaDan, I've read of you using MMO in the gas before... Would you recommend it over a product like Stabil? Or to use both products together?
I've always treated with Stabil.
Also, do you add MMO to your engine oil as well?

I only add it to my fuel, and at most 1 ounce for a full tank. You could use it with Stabil, but if you use the Marine stabil (blue stuff), it contains a light oil that does the same thing. The main difference is, MMO is cheaper lol. I only switch to stabil when I know I will be storing the bike for a few months (ie, winter). I can also easily get ethanol free 87 and 91 octane, so I haven't had to deal with the ethanol equation too much.

I am sure there are properties of the MMO beyond the reason I use it, which is mainly to keep a light coat of oil on the bare metal in the tank, and lubricate and protect the moving parts in the carb from wear. Marvel claims it will also lubricate the valve face and seat and prevent some wear in that area as well, but I have no experience of my own to really back that claim up. It is also possible that it does help keep varnish from building up, but again, I can't say. I never let fuel sit in the bowl long enough to find out.

https://www.youtube.com/watch?v=yPO-BI6CvGc&t=1565s

I'd be content with regular gas. My only concern with Ethanol added is it might absorb air moisture and internal rust. Or react with any rubber/plastics that a not compatible.

Not too convinced by their test, too much left unanswered by that video, and some of that stuff, like seafoam, isn't meant to be a stabilizer, it's a solvent.

Stabil Marine works great. With or without ethanol, and with or without a fuel additive, any carbureted engine should have the bowl drained before storage. Lawn mower, motorcycle, tractors, etc. Carburetors don't like having fuel sit in them, no matter what kind of fuel it is. If it doesn't oxidize like ethanol fuel, it will varnish and require some carb cleaning. Bike specific, I also only store a bike with a full tank. Even if the fuel does go bad, it protects the tank from rusting out due to condensation or plain moisture exposure in the air. A few bucks worth of gas vs. hundreds for a tank isn't a bad trade off.

I have stored E10 fuel with marine stabil and it still worked 8 months later, no running issues, no moisture issues.

I have used Marine 360 Stabil from brand new... No problems. I will just continue using that product and not worry about MMO. I use it for the boat anyway, might as well keep the same product for different hobbies.

Hey Megdan,

That is 1 year of testing result every month for 1 year. with little to no difference in performance. the are also to other variables being tested inside and out doors untouched every 6 months. I just linked the most recent test results.

Don't let the false teeth fool ya, Taryl Dactyl knows his stuff.

If you want to use brand X by all means do but from what I've seen modern fuel seems to be fine enough without it. I understand and agree with the %ethanol fuel concerns and if all you can get is ethanol added fuel in your area than a stabilizer might be beneficial. That's why I just use regular unleaded in all my small engines.

Fuel quality (and additive packages from the fuel maker) can also vary by region. I have seen E10 87 stored in a gas can in a climate controlled garage, go bad enough after 6 months that it wouldn't run well in a bike. Changed out for fresh fuel and it fired right up and had no run issues.

I don't use it all the time, only when I park my bikes for the 4-5 months it's cold as hell and icy outside where I live, and I would rather not take my chances.

I saw this test while not conclusive does shed light on the effects of ethanol. Again from Project Farm

https://www.youtube.com/watch?v=UvS_D4_lF5U

Here is another test interesting. I confess I use Marine 360 with non ethanol fuel.

https://www.youtube.com/watch?v=chsGBhB5g7o

My only issue with Ryan's video is he says tanks are all plastic now. As far as I know all Chinese motorcycles have steel tanks so rust is a big issue for us. Actually all 3 of my Motorcycles have steel tanks and I believe even the 2021 CB500X still uses a steel tank as well.

I think most bikes are still steel. Many have plastic covers on them now, but the actual tank itself is still metal.