Hello, I recently rebuilt my 1998 Johnson 225. It runs great, but now that I have about 5 hours on the break in I realized that the cylinders are scored. The compression was uneven, and I checked a few of the cylinders using a borescope and found the scoring. I though it blew up last time due to the crankcase halves not beings sealed properly, and I made sure they were sealed properly this time. I have came up with a few potential problems, and I was wondering if anyone could point me in the right direction or give any other suggestions. These are the potential issues I came up with:
Low fuel pressure: I put a fuel pressure gauge and clear hose in the line. There is no air in the fuel. However, the fuel pressure is somewhat unsteady. It good most of the time, but every two seconds or so it will drop and recover almost immediately. Is this normal, or is this a sign of a bad fuel pump?
To Hot/Cold: Is there a good way to check the temperature of the motor to make sure it is operating at the correct temperature? And what is the correct temperature? The water pump was just replaced, and the water pressure is good.
Lower Crank Case Seal: #6 cylinder has the lowest compression, so I thought there might be a problem with this seal. However, the rest of the cylinders I checked were scored as well.
It doesn’t appear the motor is running lean. The spark plugs looked good when I pulled them, which is why I thought it may be a cooling issue, but I don’t know how much you can actually tell by looking at a spark plug. Any help is appreciated!
Thanks!
Low fuel pressure: I put a fuel pressure gauge and clear hose in the line. There is no air in the fuel. However, the fuel pressure is somewhat unsteady. It good most of the time, but every two seconds or so it will drop and recover almost immediately. Is this normal, or is this a sign of a bad fuel pump?
To Hot/Cold: Is there a good way to check the temperature of the motor to make sure it is operating at the correct temperature? And what is the correct temperature? The water pump was just replaced, and the water pressure is good.
Lower Crank Case Seal: #6 cylinder has the lowest compression, so I thought there might be a problem with this seal. However, the rest of the cylinders I checked were scored as well.
It doesn’t appear the motor is running lean. The spark plugs looked good when I pulled them, which is why I thought it may be a cooling issue, but I don’t know how much you can actually tell by looking at a spark plug. Any help is appreciated!
Thanks!
