350vranger
New member
I have a 150 mercury black max. The serial plate is a beat up and can't read the numbers. The freeze plug on top is (667378. Could any one lead me in the right directions. On what year and model it is. I have problems with engine and can't seem to figure out what's going on. Idles fine and will rev up if you manually open the butterfly's but when in gear with the gear shifter it just bogs the motor down. The oiler has been removed. It have a mist To it and blows the vacuum line off the number one cylinder.check the compression and leak test have 112 on all cylinders. Any help about this motor would be greatly appreciated. This my first mercury I've always had johnson