swimmin' for shore
Chief Petty Officer
- Joined
- Oct 25, 2004
- Messages
- 490
I have in the shop a 1978 200 HP Johnson. I'm familiar with how compression works but am getting 83-85 lbs. of compression across all 6 cylinders. The number seems low. We charged the battery to be sure and got the same readings. On the other hand, even compression, even if low, makes me think its not blown. Worn rings, or is that a good reading on an engine this size? The same compression tester on a 3 cylinder that age would have me reading between 115 and 125 on a good engine so it's not just a low compression gauge. Any thoughts?