Mini-stroke Stock bore

[bakaracer]

ok, thanks for the advice. Howbout a V8 copy pipe. Will that work for now?

if it has a 26mm inlet on the pipe yes,if its larger you will loose torque.

[HELLAFLUSHED!]

oh okay, thanks for the input! And another question... What kine of grade gas is good for moped? 87, 89, or 92? And why? What will happen if i use the 87 grade gas, the lowest one?

I'm currently running the highest one, the 92..

[Bear45-70]

oh okay, thanks for the input! And another question... What kine of grade gas is good for moped? 87, 89, or 92? And why? What will happen if i use the 87 grade gas, the lowest one?

I'm currently running the highest one, the 92..

Stock scooter engine run in the 7 to 1 compression ratio area and require no more than 87 octane. The expensive stuff will not improve performance, in fact it can degrade performance. If you have a big bore, it will depend on your compression.

The higher octane fuels have no more energy per gallon than the 87 octane fuel. All increased octane number does is prevent preignition with higher compression ratios. 93 octane will handle 10 to 1 compression just fine and these scooter don't live long there without some real fine tuning on the owners part.

[HELLAFLUSHED!]

So can you explain it in smaller words? Lol, im sorry i couldnt really understand. So the higher octane gas doesnt really do anything, and what is the pre-ignition stuff? And the higher octane should match with the compression ratio and the bore?

[Petrock's 1984 Spree]

If you have a lower octane gas, the mixture can pre-ignitie because of the high compression.

As pressure goes up, heat also goes up. If your
mixture ignites before it should, then you can screw up just about everything in your cylinder. It's a very bad situation.

The higher the compression, the higher octane fuel you should use so you don't risk pre igniting your mixture and screwing up your bore.

[HELLAFLUSHED!]

So if your running a 72 with low compression, you still use 87 octane gas?

[bakaracer]

So if your running a 72 with low compression, you still use 87 octane gas?

nope!!! cylinder compression and compression ratio is 2 different things. pretty much everyone gets those mixed up. once you have gone to a big bore, you should be running 92 octane or higher gas no matter if you lower the cylinder compression of a big bore.

[HELLAFLUSHED!]

Oh okay okk, so howbout with a 66 bore? What octane gas do i use?

[Petrock's 1984 Spree]

Baka wants you to run 92 octane no matter what if you swap your stock cylinder for a big bore.

So run 92 on your 66cc. Trust baka's advice, he knows his stuff really well

[HELLAFLUSHED!]

haha! Ok thanks guys. I think im going to pick up my friends 66 today but not too sure yet. So in the meantime while running my stock bore, 87 is fine? lol, sorry just want to get things clear.

[kingkamehameha]

Eh oahu boy I thought you guys new how for wrench on bikes. Mabey you should come kona so we can school you on it

[HELLAFLUSHED!]

Well there may be other guys knowing everything about wrenching but as i said, im still knew to the scene so im still learning.

Lol, and btw i know how to wrench... Screw, nuts, bolts, and what not. In particular, "Wrenching". But we're talking about GAS.