Switching from Volvo TBI to Carb on a 1996 5.7 GI

Scott06

Fleet Admiral
Joined
Apr 20, 2014
Messages
7,554
Follow up after putting 30+ hours on the new setup. The 5.7 runs like a top with the new Edelbrock 1409 and Walbro fuel pump. I’m guessing my fuel burn is around 10 gallons an hour running at 3000-3100 rpm 26 mph. So far so good. Again a big thanks to all the helped out!
nice I prefer carbs for these applications exactly for the reasons mentioned.

I keep a carb kit for them on hand, but havent had to use it.

Did you have to change jetting on it for the 5.7? On my 5.0 only thing I had to do was tweak the accelerator pump nozzle and linkage. There was some slop in the linkage that lead to a lean spot on holeshot. Spent time messing with jetting, later put a AFR meter on it and saw it go way lean for quite a time, then swing way rich as i had 2 wrongs trying to make a right. I think I ended up back at stock jetting and step up rods just a bigger accel pump nozzle and bend the linkage so it was under spring pressure from the pump all the time.
 

camboat

Seaman Apprentice
Joined
Dec 1, 2025
Messages
42
I didn’t change anything on the edelbrock 1409. I just adjusted the air mixture. So far so good.
 

camboat

Seaman Apprentice
Joined
Dec 1, 2025
Messages
42
I’m having a weird problem with my oil. I can run the boat 3 days in a row and the oil on the dipstick stays the same. When I have it pulled out and it sits for five days or more the dip stick reads low at the add mark when back in the water. I’m using Volvo 25-45 non synthetic. Any ideas after switching from TBI to a1409. Edelbrock carb. The engine is running so good. No oil leaks that I can see.
Running at 3200-3500 rpm oil pressure is 60-65 lbs. no smoke or oil sheen at startup. I didn’t change the valve cover breather. No PCV valve. Just a hose from each vale cover to flame arrestor.
Thanks for any help.
When I bought the boat used the owner said the engine only had 80 hours on it. 🤦🏻‍♂️
 

camboat

Seaman Apprentice
Joined
Dec 1, 2025
Messages
42
I’m having a weird problem with my oil. I can run the boat 3 days in a row and the oil on the dipstick stays the same. When I have it pulled out and it sits for five days or more the dip stick reads low at the add mark when back in the water. I’m using Volvo 25-45 non synthetic. Any ideas after switching from TBI to a1409. Edelbrock carb. The engine is running so good. No oil leaks that I can see.
Running at 3200-3500 rpm oil pressure is 60-65 lbs. no smoke or oil sheen at startup. I didn’t change the valve cover breather. No PCV valve. Just a hose from each vale cover to flame arrestor.
Thanks for any help.
When I bought the boat used the owner said the engine only had 80 hours on it.
Today I went out crabbing for 3 hours. No oil burn from yesterday and today. I’m going to install a catch can system to each valve cover vent tomorrow. The inside of the carb and vent hose are a little oily from the valve cover vents when running the motor hard. I usually cruise at 3000-3500 rpm. Motor runs great!
 
Top