1985 150 compression

[WRIGHTWARREN]

Does anyone know what the compression should be for a 1985 150 evinrude #e150tlcos? I was told this particular motor came out with only around 100lbs compression.is this true? I tested the compression and got 75-80 on all 6 cylinders.is this okay or should it be more? If this is ok fine but if it should be more would it be head gaskets since they all are in close range of each other? Im having trouble getting it to stay running.it will run a couple of minutes then die,idling or reving up.pump the bulb and it will start up and do the same thing.new primer bulb and hoses,plugs,vro,tank.im running out of options.

 

[emdsapmgr]

Re: 1985 150 compression

Your 150 is the base model for that year. (not a GT/XP version) Compression would be round 95+. It's considered normal for compression on each cylinder to be within 10% of the others. Yours are. What's not normal is for the compression to be over 10% low on all cyls. Some things to consider on your readings. 1. the battery needs to crank the engine rapidly to get correct readings. A weak-cranking battery will affect your results. 2. each person's compression gauges may read differently. Try another gauge. 3. You need to perform the test with all the plugs out of the engine. 4. You may find that if you run a can or 2 of Bombardier Engine Tuner through the powerhead that the compression numbers will come up somewhat. Usually on a high-hour powerhead, they will. Follow the directions on the back of the can.

 

[JB]

Re: 1985 150 compression

Many of those big V6s are low compression engines. 75-80psi is not unusual in a normal and healthy engine.

 

[emdsapmgr]

Re: 1985 150 compression

Agree with JB's comment. My comments parallel JB's thoughts..lots of things to check before you condemn the powerhead. I doubt your running issues and the compression numbers are related. I'd be looking at the fuel delivery system first.