MASTER Brian
Senior Chief Petty Officer
- Joined
- Mar 26, 2006
- Messages
- 738
As the title says a buddies V4 Johnson lost compression on the bottom Starboard side cylinder. The others are 105, 112 and 112. I can't tell for certain but it appears there is some small pits on both cylinders on this side as well. My guess is he lost a ring. About 8yrs ago I went through the same thing on my E-XP150 and had to rebuild the entire engine. He's owned the boat about 3 weeks and I know he's a bit cash strapped, so I feel for him. On that note, I'm sure I told him about de-carbing the motor, but of course he didn't listen.....it was running too well!! :facepalm: I learned that lesson when I lost the ring on my motor.
So my question, is it even worth trying to decarb it at this point, is there any chance that ring isn't in a million pieces and is just stuck? It's a 1994 Johnson 140hp. When I lost the ring on my XP150, they sent me what I believe was a V4 gasket kit instead and they didn't want it back, so I still have it and it appears the water jacket and the head gasket are the same, so I'm hoping for his sake he can use this kit....after 8yrs the sticker is worn off and thus I can't see what it exactly fits. I figure first order of business is to pull the head and take a look and go from there, but since it's been 8yrs since I've rebuilt an outboard, I'm going to need a bit of advice.
If, like I suspect, he lost a ring, can we just pull the cylinder, bore/re-sleeve that cylinder and put it back together or should we tear it all apart? I can't remember all the specifics, but I know it's typically not an easy fix.
What about the carbs? Should he rebuild them all or just have them tuned by the shop once all back together?
Like I said I rebuilt my engine myself, it was my 1st and only outboard rebuild and i recall it being a lot of work, but doable for me. Problem is, when I did mine, I know I went above and beyond replacing parts because I didn't want to be back into the motor in a few years and I had the $$$ I could spend. I remember pulling the entire power head, rebuilding carbs, changing the water pump, installing a brand new VRO pump, replaced a few electronics, etc. Once together I opted to pay the shop to sync the carbs and time the motor as it was easier to pay them ~$100 than spending the time to do myself.
***What started this was he mentioned it wasn't running right and that he needed to heli-coil a spark plug thread. He brought the boat by and a glance into the head(s) made me question things and thus I ran a compression test on it. The top cylinder on the starboard side is the one with the bad plug threads....a new plug won't thread, but the old one does. Figure the difference in plugs gasket compression is what makes the difference. Wonder if this had any bearing o
So my question, is it even worth trying to decarb it at this point, is there any chance that ring isn't in a million pieces and is just stuck? It's a 1994 Johnson 140hp. When I lost the ring on my XP150, they sent me what I believe was a V4 gasket kit instead and they didn't want it back, so I still have it and it appears the water jacket and the head gasket are the same, so I'm hoping for his sake he can use this kit....after 8yrs the sticker is worn off and thus I can't see what it exactly fits. I figure first order of business is to pull the head and take a look and go from there, but since it's been 8yrs since I've rebuilt an outboard, I'm going to need a bit of advice.
If, like I suspect, he lost a ring, can we just pull the cylinder, bore/re-sleeve that cylinder and put it back together or should we tear it all apart? I can't remember all the specifics, but I know it's typically not an easy fix.
What about the carbs? Should he rebuild them all or just have them tuned by the shop once all back together?
Like I said I rebuilt my engine myself, it was my 1st and only outboard rebuild and i recall it being a lot of work, but doable for me. Problem is, when I did mine, I know I went above and beyond replacing parts because I didn't want to be back into the motor in a few years and I had the $$$ I could spend. I remember pulling the entire power head, rebuilding carbs, changing the water pump, installing a brand new VRO pump, replaced a few electronics, etc. Once together I opted to pay the shop to sync the carbs and time the motor as it was easier to pay them ~$100 than spending the time to do myself.
***What started this was he mentioned it wasn't running right and that he needed to heli-coil a spark plug thread. He brought the boat by and a glance into the head(s) made me question things and thus I ran a compression test on it. The top cylinder on the starboard side is the one with the bad plug threads....a new plug won't thread, but the old one does. Figure the difference in plugs gasket compression is what makes the difference. Wonder if this had any bearing o
