Compression ratio

Hello,

What is the compression in PSI if i have à compression ratio of 15.0:1?
This is for WR 240 LC 1985 with a double ring piston and a new sleeve.

Thanks

my high mileage 88 250 is listed at 15-1....this year the compression was 210-215 psi after about 4 kicks...i would say you should see 200

Then i have a big problem. My compression is 150-160 psi. The engine cost me 600$ (new piston and new sleeve) and i don't have the full compression... What do you think is the problem?

The mechanic ???

are you sure its 15 to 1? i thought only the 87-88 long stroke 250 had the higher compression....the earlier 250s were 12 to 1, and if is the case, you compression is spot on....maybe someone else can offer some insight...the 85-86 had bigger bore, shorter stroke..much like the early 80s 250s...with a fresh piston in my 84 it sat about 155psi..

have you broken it in to seat the ring?
about 15 minutes should do the trick to get an accurate number

Don't confuse the 87/88 250 with anything earlier as they are very different.