[ScoReb]

Hi all, I'm looking at purchasing a used boat which is fitted with a 1996 Yamaha 150. I want to do a compression check on it but Im not that familiar with 2 strokes. Can anyone tell me what pressures to look for and maximum variances between cylinders?

[corm]

Hi ScoReb,The cyl 1 & 2 should be the highest and 5 & 6 will read the lowest. Max difference is 15#this means trouble. Personally I think 6-10# is alot. Sorry I can't find the spec no.for the comp, but hope this helps some.corm

[ScoReb]

Thanks for the reply Corm, I'll be doin' the check late this afternoon. Strange that it is normal for certain cylinders to be higher/lower than others, but thats why I'm lookin' for advice here because I know little to nothing about outboards At least now if I find the numbers to be the way you say they may be, I'll feel better about it. btw, comp. test by his marine mechanic says he measured 130# across all 6, I'll find out for sure later today.

[corm]

Hi SoReb,Hope theyare even like he said . That wwould be great.corm