I dont know what else to do!

[trainwrecker22]

I repowered my boat after I bought a lemon. It had a 305 5.0L merc. I put in a 350 5.7L long block. used old distributor, intake, and carb. The old 305 ran good except for the lower end. I figured the extra few cubs would be ok. Plus I think the 350 is a superrior engine. Well I can not get the dam thing to run right. It spitts and sputters and I have done everything I knew or thought. New plugs wires cap rotor, new filters all around, have good fuel pressure about 13psi. The engine was a rebuild from michigan motorz. But this is how she runs. I can not get over 1300 R's http://youtu.be/uZDzOv7paIA

 

[Rick Stephens]

That sure sounds like spark plug wire order....

 

[thumpar]

Check firing order and timing.

 

[Eric 3.7LX Alpha 1]

13-psi fuel pressure sounds a little high to me for a carbed engine. I agree with the others on the firing order/ timing.

 

[trainwrecker22]

I will check firing order again but I have checked it more than once. I don't think that's the issue. I have went through everything I know. I was told that it may have to do with the thunderbolt iv (4) ignition. I don't know

 

[Maclin]

I wold check valve lash again. I do have a question about how the cam was broken in, some of that popping back thru the carb seems like cam timing or worn cam lobe(s).

 

[alldodge]

I will check firing order again but I have checked it more than once. I don't think that's the issue. I have went through everything I know. I was told that it may have to do with the thunderbolt iv (4) ignition. I don't know

Agree with others 13psi is way to high, your fuel pressure should be between 4 to 7 psi. Do you have a mechanical or electric fuel Pump and what model is it?

As for the sputtering, if it is not fuel dripping into the intake from the carb, I would suggest start over with the basics. Put a timing light on the coil wire and watch the flashes. If it does not flash smooth and consistent, maybe the distributer, coil or amp. If it's in this area run through the TB-4 troubleshooter.

Next bring the engine around to number 1 TDC. Remove the valve cover on the port side to make sure valves are closed. Then check distributer orientation. Note engine rotates counter clockwise, distributer rotates clockwise

 

[Bondo]

I will check firing order again but I have checked it more than once. I don't think that's the issue. I have went through everything I know. I was told that it may have to do with the thunderbolt iv (4) ignition. I don't know

Ayuh,..... I'd sooner think ya missed something along yer way,....

Start at the basics, timin', 'n firin' order at at the top of my list,....
The T-Bolt seems to be firin',....

What do the spark plugs Look like,..?? Color,..?? Wet,..?? Dry,..??

'n I Agree, 13 psi, is Waayyy high,... 4 to 7 psi is more like it,....