Basicly anything over 100 psi would be acceptable. Also, there should be no more than 10-15 psi variance between cylinder readings.
between 90-120
130lbs
50 to 1 ratio
The 1991 model, 90 hp Force outboard requires a 50-1 ratio. This is roughly one pint of 2 cycle oil, to six gallons of fuel.
briggs doesn't offer compression ratings for their engines. I will usually pull it 3 to 5 times and look for 90 to 120. anything less is a problem and if it doesn't hold compression there is a problem
Here are a couple.The compression force of that machine is measured in tons.I was amazed at the compression force I felt.
I have a 2005 and compression should be close to 120 psi. Normally a good engine will have compression between 115 and 130 psi but a leak down test should be performed also to know the full condition of a cylinder.
Compression on a 1975 70 hp Evinrude outboard refers to the pressure generated within the engine's cylinders during the compression stroke, which is crucial for efficient combustion. Typically, compression readings for this model should be between 90 to 120 psi. Low compression can indicate issues such as worn piston rings, damaged cylinder walls, or valve problems, which can affect engine performance and reliability. Regular compression testing is essential for maintaining the health of the outboard motor.
The compression for an 85 hp Force outboard motor typically ranges between 100 to 140 psi per cylinder, depending on the specific model and condition of the engine. It's important to ensure that the compression is relatively uniform across all cylinders for optimal performance. If any cylinder shows significantly lower compression, it may indicate potential issues such as worn rings, valves, or gaskets. Regular maintenance and checks are crucial to keep the engine running efficiently.
The listed dry weight for a 1993 model, 90 hp Force outboard is 249 lbs.
The cylinder compression on a 1985 Evinrude 25 HP motor typically ranges between 90 to 120 psi. It's important to ensure that both cylinders have similar compression readings for optimal performance. If the readings are significantly lower, it may indicate issues such as worn piston rings or cylinder wear. Regular maintenance and compression testing can help ensure the engine is functioning properly.
Low compression, 2bbl carb = 230 hp High compression, 4bbl carb = 290 hp 1964 442 330 engine = 310 hp