Compression Readings for 1989 Johnson 150

[Jan Schmidt]

" Hello,

I am looking for s

" Hello,

I am looking for some help prior to the purchase of a used boat. The boat has been meticulously maintained and is in great shape, The motor looks fine and the owner estimates ~200 total hours which from the looks of the boat is beleivable. The motor looks fine under the cowl. I had the dealership which is brokering the baot check the compression and they got readings of 90 to 100 psi on all cylinders and stated that they meet manufacturers spec's. This sounds very low to me, but otherwise everything seems fine.

Do I need to walk away or am I overly concerned?

Thanks in advance, Jan "

 

[joereeves]

"Jan.... In past years, the co

"Jan.... In past years, the compression readings were quite a bit higher, approximately 125/135, somewhere in that area. However, right around the year of the engine you're speaking of, OMC lowered the compression (about 90 psi) to compensate for the lower quality fuel that was available. Bottom line is that the dealership was being truthfull about it.

Joe

"