250x, 12:1 can I use pump gas or do i need race fuel

[welpracing]

I am redoing my lil sisters 250x and it needed a .050 pistion and honda discintued it so i had to go with weisco and it is a 12:1

can I use 93 octane pump gas and be fine with the compression ratio or do i need to get a higher octane.


anyhelp would be great. Thanks Brandon

[GPracer2500]

If the actual assembled compression works out to 12:1 on your 250x, then there is very little chance you'd be able to avoid engine knock with pump gas. There are a lot of factors other than the static compression spec assigned to a piston that go into the minimum required octane rating of an assembled engine--but I'd count of pump gas not cutting it.

[REDRIDDER]

i would say 110 octane or a little lower would do you just fine but definitely not pump gas.

[Moto250X_Rider]

i know ppl that mix klots and pump gas to save money.....2 gallons of klots to 3 of 93 pump......that could work for u....but i would just run race gas and save yourself from messing up your motor

[pimpin330ex]

98 octane vp race gas will get the job done

[Kickstarts-suck]

chit i ran 93 fine so went to 91 and it did fine so ran 87 with no problems with my 12:1 compression 250x no problems at all.

[wilkin250r]

At 12:1 compression, you would need race gas.

However, Wiseco isn't your only choice. It's the one you are most likely to find, because they advertise everywhere, but it's not your ONLY choice.

Powroll makes an 11:1 piston.

A company called Arias USED to make larger bore pistons in lower compressions, but I think they are under a different name now. Maybe do a google search for Arias 250X.

Many race shops have their own custom pistons, and most will sell a piston kit by itself without requiring thier own in-house installation. Try the LINKS section.

It's boring and tedious, it may take longer than three minutes, but you can certainly find lower compressions ratios if you're willing to look.