compression

[jaysea1]

What should my compression be reading? I live in Phoenix AZ...I think the elevation is about 1300 ft above sea level. My bike is only 1 year old, with T-5's and twin K&N's(no air box)Everything else is stock. I kicked her 10 good kicks(throttle wide open,fuel off, ignition off.) The gauge read 115 psi on both sides. I warmed up the engine first. I run klotz @ 32 to 1, broke her in with 2R. I think it's a little low...is this too low?

[J.J.]

I'd say that's in the ballpark considering stock head and elevation, do another test on a cold engine and post back.

[frocashmoney24]

sounds pretty damn good to me

[cam2]

I kicked her 10 good kicks(throttle wide open,fuel off, ignition off.)

 

you might want to try it again and kick it over more than 10 times. when i checked mine before and after i put on the coolhead with 20cc domes i had to kick it quite a bit in order to get a good reading. i know it sucks but you'll need to kick you butt off. i'm basically at sea level, the bike was about 8 months old when i put the new head on and my new gauge read 130psi on each cylinder before and 181psi after.

 

this chart is from nossmachine.com. remember these are approximate numbers, but damn close to what i read.

 

Sea Level 1000' 2000' 3000' 4000' 5000'

18cc 238 229 221 213 205 198

19cc 211 203 196 189 182 175

20cc 184 177 171 165 158 153

21cc 157 151 146 140 136 130

stock 130 125 120 116 112 107

[jaysea1]

Thanks for the replies everyone. I got a look at the pro design chart. It calls for 130 psi @ sea level and 124 psi @ 1000 ft above. I think my elevation is more like 1100 ft above sea level. Did the test again still 115 psi. Anyone with same elevation get a stock compression test? I broke it in easy...varying the rpm's for one tank of gas. I didn't pinn it until half way on the 2nd tank of gas(could'nt resist) Bike is all stock except for pipes.