I have an 1989 Johnson 150hp VRO V-6 on a 21 ft walk-around cuddy. The crankcase no longer delivers enough vacuum pulse to properly run my VRO fuel pump. My VRO pulls enough gas to keep the carb float chambers full when I run at 2500 rpm or less. Higher rpms result in gas starvation. If I pump the bulb, the boat runs very well at high rpms.
Running on an auxillary tank hooked directly to the VRO doesn't improve performance. Also I've installed a new VRO & pulse limiter, and did an extensive decarb. The problem seems to be low engine compression combined with a hairline crack (which I just found) on the outer surface of the crankcase. A small amount of oil seeps out the crack.
I cleaned the crack and covered it with JB Weld this morning, and hopefully that will help.
Can I improve my compression by increasing the gas-oil ratio? I'm thinking the extra oil may help seal the worn rings. All 6 cylinders have compression between 85 and 90. I gave each cylinder 2 cranks which brought them all up into the 60 area, then I gave another 6 cranks which put them at their maximum in the high 80's. I put 30w oil in 1 cylinder and it rose to 145.
Do you think premixing at 40:1 or even 32:1 would help the ring seal? Also, would the VRO use less vacuum pulse if I disconnect the oil side and just run the gas side? I'm debating with myself whether to do this, so I'd like to hear some other opinions.
I don't have the tools or skill to do a rebuild, and I don't think the engine is worth paying what it would cost to have someone else do the rebuild.
Thanks!
Running on an auxillary tank hooked directly to the VRO doesn't improve performance. Also I've installed a new VRO & pulse limiter, and did an extensive decarb. The problem seems to be low engine compression combined with a hairline crack (which I just found) on the outer surface of the crankcase. A small amount of oil seeps out the crack.
I cleaned the crack and covered it with JB Weld this morning, and hopefully that will help.
Can I improve my compression by increasing the gas-oil ratio? I'm thinking the extra oil may help seal the worn rings. All 6 cylinders have compression between 85 and 90. I gave each cylinder 2 cranks which brought them all up into the 60 area, then I gave another 6 cranks which put them at their maximum in the high 80's. I put 30w oil in 1 cylinder and it rose to 145.
Do you think premixing at 40:1 or even 32:1 would help the ring seal? Also, would the VRO use less vacuum pulse if I disconnect the oil side and just run the gas side? I'm debating with myself whether to do this, so I'd like to hear some other opinions.
I don't have the tools or skill to do a rebuild, and I don't think the engine is worth paying what it would cost to have someone else do the rebuild.
Thanks!
