#1: Compression Test at Altitude
Author: TrekNut, Posted: Thu Aug 31, 2006 7:41
pm
Hey all! I've been getting an
'81 XV750 road worthy that had seen a ton of storage until I bought it
a few weeks ago. The other day I did a compression test and almost
seized! #1 was 118psi and #2 was at 120psi. My "great deal" on a bike
with only 15,000 miles on it was starting to look sour. Gee I was really
looking forward to telling the wife I'll be spending bucks on a top end
job.
Anyways, after looking at the manual for the fifth time
I finally got around to the fine print ... "at sea level"!!! I'm in Santa
Fe, NM at 7000'!!!
I did some searching on the web and found a
"Tech to Tech" page by Brian Manley in Colorado which listed the
conversion factors. I've found so much useful info on this forum and now I
can give a little back! The following are the conversion factors you need
to get your compression reading accurate to a sea level reference,
wherever you are. Find out your elevation, (to the nearest 1000') and
multiply your gauge reading by the corresponding conversion factor and
voila!...no heart attack.(hopefully)
Elevation Multiply by:
1000' ----- 1.029 2000' ----- 1.060 3000' ----- 1.093
4000' ----- 1.126 5000' ----- 1.160 6000' ----- 1.196
7000' - ---- 1.233 8000' ----- 1.272
Hope this is usefull
for at least some of y'all...
TrekNut p.s. I know someone is
going to reply to this saying they live a 12000' and to them I say
"compression is the least of your problems you oxygen-starved hermit" |