11:1 piston... pump gas?

[monkeydude36020]

Ok so Ive noticed running 93 in the 400 after my rebuild its fine rolling through a field or riding on the road, but I was puttin around the yard today practicin on my wheelies and it seemed like it was getting really really hot. Mods are in sig. Is 93 ok or shouuld I run race gas or a mix in it?

[bkelley]

11:1 is generally considered premium pump safe.

[monkeydude36020]

Ok then maybe its ok, I just dont remember it getting that warm with the stock piston in it... And its only 60F outside. I guess its normal for a high comp motor to run hotter?

[bkelley]

Yeah, a high compression piston, and a bigger piston in general, is going to produce more heat. Running a higher octane fuel won't lower the temperature. Higher octane just makes the fuel harder to ignite. As long and you aren't experiencing detonation, you're fine. If you're uncomfortable with the heat, go for a SPAL fan. Or get your bike into 4th or 5th gear. They are air cooled engines after all.

[unitednations]

I noticed more heat as well. But i have used 93 gas for over a year and have had no problems. If your going slow there isn't much air to cool down your engine. Its fine. Run it.

[PaRedneckRiders]

i would invest in a set of air scoops, there like 30$$ and help direct air toward to oil cooler

[bkelley]

Read his signature, he has air shrouds.

[rooster300ex]

Yea higer compression will run alil hotter, and goin slow not much air is flowing. Every now and then get er goin in a higher gear to cool it down a bit.

[PaRedneckRiders]

sry about the stupid post i skipped his sig.

[jzexrider]

I have an 11:1 and run it on 93 pump also and it does the same thing. It gets really hot messin around but on faster trails and mx tracks, its fine. Just the air cooled design. Im looking into a fan next.

[monkeydude36020]

Thanks for the input guys, this makes me feel alot better!