87 or 92 octane gas

[kglazer]

hey guys i bought a kymco super 9 ac in the beginning of the summer second hand off of craigslist. the guy said it takes regular 87 octane and i Have put about 10 tanks in so far all of regular gas the scooter has been running perfectly fine. yesterday i was looking through the Manuel and came across what type of gas to use it says that it takes 92-95 octane gas. so my Dilema do i keep running 87 since i have been using it with no problems or do i need to switch to 92 octane gas?

[mccanic]

i would go with 92 octane as the Manuel says

[90GTVert]

I usually run the lowest octane gas that I don't hear any detonation with. If you've noticed nothing out of the ordinary, you should be OK with regular. The crackle of detonation is very obvious from my experience, and tends to make me cringe, so you should notice it. If it's extra hot and you'll be running hard for long, it may not be a bad idea to go with premium to avoid any possible trouble once heat builds up.

[kglazer]

yeah i didn't think anything of it. threes no detonation. the only thing that i still have yet to figure out y is a vibration throughout the whole scooter at 40-45mph like its hitting the limiter and just shaking. i dint think this is due to the gas. should i be worried about any problems in the future and could i possible go faster with the 92 since its recommended for the engine?

[90GTVert]

You won't go faster with the 92 unless you do something else to need it like raise compression or advance timing. As long as you don't have detonation, should be nothing octane related to worry about. Fuel octane won't limit your speed under any normal circumstances.

[kglazer]

ok thats what i figured. so now to find out what this vibration is coming from. i rlly dont think its the tire cuz it only happens at top speed when at wot. so what could it be?

[jmkjr72]

one other thing to consider the manuals normaly are not writen for the us and normaly mention the ron number not the aki number that we use in the us for octane rating
a ron of 92 is actualy a aki of 87

[lshigham]

^^^

This.

[90GTVert]

I always manage to forget that part. Thanks.

[jmkjr72]

yeah yamaha and honda are about the only ones i can think of that make us specific manuals

[Goosey]

I agree, if it's running good your ok. I pay the little extra not so much for the octane boost, but because I have a Shell station that sells a no ethenol premium.

[WT100]

jmkjr72 - got it right on the ratings.

And i'm with Goosey to the extent that i use the higher one to avoid ethanol if i think the scoot is going to sit for a while. Otherwise 87 has been fine in everything i run.

BTW nice score on an S9! I'm hoping my dealer will break down and sell me the S9 LC he is hoarding. I tell him that having 2 S9 LCs is just gluttony...

[kglazer]

wt100- i totally agree having 2 is just unfair!

and thanks guys for the response. what is a better idea. i know i want to achieve about 40-45mph cruising speed as there r the speed limits in my area and i know having a 150cc engine without a m endorsement is illegal. but I'm highly considering dropping in a 4 stroke 150cc engine on my s9 cuz i love the body and it will help maintain the 50cc look. or do i get a 70cc malossi bbk for my s9? money wise is not a issue for me I'm more looking at the reliability and less troubleshooting down the road for example replacing parts cuz the engines running more power and rpms? so im leaning more towards the 150cc swap cuz i can keep things stock and obtain my cruising speed instead of having a kit and running my 50cc engine at high rpms.

[Goosey]

Different engine mounts, 50cc bottom, 150cc top. Not a simple swap. Plus the issues if you get caught. Go the BBK. Have you looked around some? Sometimes the same body styles are used in both 50cc and 150's?

[kglazer]

actually my 50cc kymco super 9 scooter mounts at the top i checked and so do gy6 150cc engines so thats not a problem. its finding the engine and wheel combo together since gy6 and my kymco super 9 have diffrent spline counts?