hey guys a 300ex tore me up(stock ex)

[suzuki LT250R]

Don't you have problems fouling plugs with your 50:1 mix? I run 40:1 in my LT and I thought that was a little steep.

[1 bad shee]

like i say i only ran about a half tank off it,,,my plugs was black and wet when i took them out for the compression test

[370banshee]

50:1 is really lean. if your fouling plugs at 50:1 you must be running way to big of mains

[PA_Banshee]

yeah like 370 said... you are taking that ratio the opposite way it's 50 parts gasoline to one part oil, which is less oil than 32 parts gasoline to one part oil. 370 do you remember what that thread was that we were bs'in about the oil ratios?

[PA_Banshee]

nevermind chris, I found it heres the thread that explains oil ratios.

There's that damn math again, why the hell do I keep doin that crap?

[Banshee]

I am not sure what the compression should be but 119 sounds a little low. Does anyone know what his compression should be?

Thanks

[370banshee]

i'm taking bretts spot here i'll do the math


psi/14.7=comp ratio


119/14.7= 8.0:1 ratio


check and manual for the spec on compresion sems to me tha might be right?? but i'm no tottally sure


oh yeah the 14.7 is atmosphereic pressure at just above sea level. it all depends whrer you live. if you live in the mountains then 119 is pretty good for compression.

[Banshee]

The manual calls for 6.5:1 which would give you a PSI of 96. So is it to much compression?

[PA_Banshee]

Accept my member gallery upload so I can post it in this thread, it's a table of compression for banshees that is dependent on dome sizes and altitude.

The following chart is a guide only. Performance may vary depending upon each individual engine's condition and setup. The following cold cranking compression numbers assume stock exhaust port timing.


Thanks, here it is...

[PA_Banshee]

So depending on where your at it looks like it could be a bad thing that it's 96 or a really bad thing.

Here's some more stats I found one day and kept in case I needed it. I'm not sure how accurate it is, but it looks like a decent approximation for what octane to use with certain psi's. Let me know if anybody has any objections to that reference. I haven't checked my compression yet, but I've been running 93 octane. Maybe I'll try stepping down to see if it knocks. If not it'd definately run cooler with the lower octane.

PSI Octane
210 115
200 112
190 105
180 105
170 98
160 91
150 91
130 87