Help with Diagnosis needed.
#1
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Help with Diagnosis needed.
After running well the last several times out. I developed a stuttering and dying of one engine when tying to get up on plane (under a load).
In Nuetral, I hear a feint miss. I can rev to 6K out of gear. Can't make to 2K rpm under load. Fuel pressure is constant (8lbs). Plugs are not fouled but moist. I changed Dist. cap, cleaned up rotor, made sure mechanical advance weights were clean and lightly lubed and operational. Plug wires in good shape and connected etc.
I am suspecting a faulty coil or ignition box. Both are Crane units. Tomorrow is my last day before insurance lay-up begins. any suggestions to check or test before I start swapping out parts?
In Nuetral, I hear a feint miss. I can rev to 6K out of gear. Can't make to 2K rpm under load. Fuel pressure is constant (8lbs). Plugs are not fouled but moist. I changed Dist. cap, cleaned up rotor, made sure mechanical advance weights were clean and lightly lubed and operational. Plug wires in good shape and connected etc.
I am suspecting a faulty coil or ignition box. Both are Crane units. Tomorrow is my last day before insurance lay-up begins. any suggestions to check or test before I start swapping out parts?
#3
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I only goosed it to little more than 1/2 throttle and it spun up there ever so briefly. Had to see what happened out of gear.
It is a 1250 dominator on 604 inches. Crane HI-6 marine ignition, Crane Fireball coil. Nology wires, NGK plugs. Holley Dominator fuel pump.
It has run well up to now.
It is a 1250 dominator on 604 inches. Crane HI-6 marine ignition, Crane Fireball coil. Nology wires, NGK plugs. Holley Dominator fuel pump.
It has run well up to now.
#4
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2112,
I had the same problem. Port engine would run like a raped ape in neutral and under load. Starboard would run at high RPM's until I put it under load, then it only went to 2k RPM's. My problem was a cracked head. You might want to check that or your head gasket. I'm not saying that's what it is, just what I had is simular to what I have read here.
Good Luck,
Sulfur 1
I had the same problem. Port engine would run like a raped ape in neutral and under load. Starboard would run at high RPM's until I put it under load, then it only went to 2k RPM's. My problem was a cracked head. You might want to check that or your head gasket. I'm not saying that's what it is, just what I had is simular to what I have read here.
Good Luck,
Sulfur 1
#5
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Man I hope not. No water in oil, overheating etc. Anything is possible.
I did adjusted the valve lash but it ran fine afterward. Problem started after a non eventful 3-4000RPM cruise.
I did adjusted the valve lash but it ran fine afterward. Problem started after a non eventful 3-4000RPM cruise.
#6
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Could be valve springs. Take the valve covers off and look for broken springs. You can also swap your HI-6M's and see if the problem is still there.
Dave
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#7
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Hi,
Are all 8 plugs in the sour engine moist? If so, I would also suspect ignition issue - at first I thought sticking timing advance weights, but you've checked them....try swapping the coils and see if the issue follows the coil.
Are all 8 plugs in the sour engine moist? If so, I would also suspect ignition issue - at first I thought sticking timing advance weights, but you've checked them....try swapping the coils and see if the issue follows the coil.
#8
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yes all are a little moist, a couple a little more so. They are the typically rich runners on my intake manifold.
Good suggestions. I will do both tomorrow.
Good suggestions. I will do both tomorrow.
#10
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Sour side coil is pretty warm. I am not running long enough to get it hot. When I let it cool for 5 minutes she fires right up like nothing wrong.
It is so foggy right now I can't get out to check things out.
BTW everything is new but the coils. I have been using them a few years. Dumb I know. Dumber still is the fact that it is one of the only things I don't keep a spare of.