Engine Gurus?
 

Are there any good marine mechanics near Worcester, MA area? Converted my 320efi(350 chevy marine motor) to carb and can't get more than 3500rpm out of it at wot. Rebuilt the motor completely and went 30 over. Full MSD ignition with edelbrock intake and carb. Tuned the motor all last summer and only got about 200rpm best. Tried about 10 different props. Drive is still good. The only part of the motor I didn't change is the cam. Would the stock cam that was for the fuel injection cause that much of a lack in the torque? Boat used to go 60 now only does about 40 tops. The thing is driving me nuts. HELP!!!! PLEASE!!!!

r u sure u got the timing right, sounds like thats where you need to chk first, is the carb opening all the way?

what is the rev limiter set at, could be that.

The stock cam is not causing a problem unless it wiped some lobes or is not installed correctly.

So, EXACTLY what was done to the engine in the rebuild?????? besides going .030 over.

In other words, post all the specs and all the parts used.

Just athought.
If MSD is a new upgrade , Check supply voltage wire guage.
Usually needs to be Inreased.
The result is a very lazy spark that will find it hard to produce a good fire at wot.
You never know!
Cheers

You obviously had to remove the cam to bore the block. Did you assemble the engine or someone else? With new pistons, what was the change (if any) in compression?

The cam does not care if an engine is efi or carbed.

Like Griff says, we need more info! Help us help you...

Had a problem like yours many years ago. Found out the two wires from dis. to box were crossed. Worth a try.

local shop
 

robinson marine in boxboro ma. 19782631100. jp, helped me work the bugs out of my 700's . worth calling.. pretty fair on rates.