I should’ve probably stated that I’m trying to sell the motor and I wanted to make sure the I’m not screwing anyone over with the compression. Sounds like I’m good.
Your assumption is correct 😂 It just seems strange that I am reading much closer to the 120 mark than the 87 mark, and I’m just trying to figure out why that would be. Doesn’t that seem strange that I would be much higher than the rated compression?
Thanks a bunch. I wonder if my motor is the equivalent to the 40BTR (120psi), rather than the 40BMH? Did your research of my serial number line it up with the BMH?
Wow, so this 4-stroke mercury was manufactured by Yamaha? I had no idea they did that.
Are you 100% sure on that compression? Because the compression went from way too low to way too high. Or maybe more likely my new gauges are incorrect. I noticed the other compression setting on your spec...
Serial number is 1C050911. I heated it up first, removed all plugs, WOT, then pulled 8 or 9 times until it quit going up (pull start). I just bought the gauges at Oreillys but they are not “top shelf”.
I hooked my comp tester gauge to my air compressor at 150psi and it reads about 135psi so it may be off just a bit, but not a lot. Using that as a correction factor, I’m coming up with 115 125 and 130 ish.
Thanks. I hadn’t looked into it. I can rebuild a carb but going into the cylinder head is above my pay grade. I thought that within 15% from the high to the low was acceptable.
I just bought a 2007 mercury 40hp 4 stroke. Rebuilt the 3 carbs and it starts and runs good but it’s a little smoky. I left the mixture needle screws where they were at. Can someone tell me what the proper setting is for this screw on each carb? How many turns from tight? I used to my old...
Howdy, I've got a 1998 Johnson 25hp (J25TELE). It has ran great for a long time. I've run this motor for almost 13 years.
Today I put it in the water and checked the pee stream like always and it was normal. However, the motor sounded a little different. Couldn't put a finger on it. I noticed...
I'm looking at a starter switch on ebay. It's part number 394020. The starter switch on my 1998 25 hp Johnson is p/n 583925. Can someone tell me if this starter switch and harness will work on my motor? The one on ebay looks good, but it looks like it is for a 50 hp, and the leads are 3'...
I've got a 98 model 25 hp 2 cylinder electric start tiller motor. Yesterday I backed it in the water and pushed the starter button and the button didn't reset - it stayed depressed. I then saw that the bare ground "cable" that goes from one of the starter bracket nuts to the screw by the gas...
Hi all,
I've not had any trouble out of this prop over the last 10 years until now. I've got a 10x11 SS Power Tech on my 25 HP Johnson. I've spun it and I need to know the best course of action...
Should I get it repaired, or replace it? The prop itself is in pretty good shape as far as I...
