BajaJim737

Converted my 320efi 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. Boat used to go 60 now only does about 40 tops. The thing is driving me nuts. HELP!!!! PLEASE!!!!

I DIG IT !!

I'm no pro but it almost sound like the teeth are off buy one tooth on the cam this making it retarted and won't addvance are you sure that you go it lined up right. Just a thought.

JIMG

are you getting full spark advance?

Griff

As you know, you're off a ton on power. You should have been able to run the same prop.

It could be any of a bunch of things. Did you use the stock cam??? Cam timing??? Ignition timing??? Carb??? Carb linkage??? Fuel pressure??? Valves too tight and hanging open???

BajaJim737

Tried 3 carbs. Used the stock 320efi cam and timing. Tried all different timing on the ignition. I am getting full advance even tried changing the advance amount and curve. Put a holley electric fuel pump and regulator on and then switched to a mechanical. Just can't figure the damn thing out....

4mulafastech

To be off that much on power it could be cam to crank timing. Were the cam and crank gears clearly marked and lined up good when installing the timing chain? Did you degree in the cam afterwards to be sure?

Griff

How does it idle????? Have you done a vacuum test???
What ignition????? and where is total timing set???

Do a compression test and then maybe a cylinder leak down test.

I'm with 4mula, I think the cam timing is off or the cam is wiped.

spazboz

iTrader: (2)

On a SBC, that sounds like just the RPM when the 4bbl would open. Make sure the carb is clean and ready to go!

Nick