Logo
FULL SITE MENU

New 350 with carb issue

P

pidde

New member
Hi
Engine is primed used the

Hi
Engine is primed used the screwdriver trick and worked nice to get the oil pressure up.

Started and run ok for 10 min yesterday but today very difficult to start. Found out that the primary fuel bowl gets full and the carb is totally flooded. I do have a new engine with electrical fuelpump and a holley 4150/4 barrel.
Took the carb apart and blowed with high pressure air and couldn't see any dirt or particles. I'm righ now very feedup and all help is apreciated.//Peter
 
"Just talked to Michigans moto

"Just talked to Michigans motorz and they said that it could be the electrical fuel pump giving to much pressure!! Is this possible?
El Pescador any comment? You seems to have a lot of experience would be happy if you could assist!

Peter from Sweden, sorry if the english is as it is......"
 
"There are two threaded plugs

"There are two threaded plugs (one on each bowl). Remove them and turn on the electric pump. If fuel overflows from either bowl, adjust the float level until the level is at the bottom of the plug hole. Then, replace the plugs.

To adjust the float level, there is an adjustment nut on top of each bowl. Remove the lock screw and turn the nut clockwise to lower the fuel level.

Yes, the fuel pump could also be giving too much pressure. The correct fuel pressure for a carburated 350 GM is 6-8 psi (.42-.56 kg/cm2)."
 
Hi
The fuel coming out from t

Hi
The fuel coming out from the overfilling tube is like open a water hose (considering the tube size of course)Looks like a lot of pressure. Should be just a small flow if correct pressure and overfilling? Have you seen so you can explain for me?

You mention that I should replace the plugs? Please explain. Re-install?
Also why did it work yesterday without any problems? Any ideas?

Thanks for your help! Sun is here (even in Sweden) and engine is outside the house;-(
 
"Thanks!
IF fuel pressure is

"Thanks!
IF fuel pressure is to high would both of the bowls flood or just the first one? I have just the first one flooding.
Also the sight glass! I got hem together with the engine but I have never fitted them
blush.gif
, can you please explain where to fit them? Seems like I will need them!

Thanks/Peter"
 
"Peter, in theory if the pump&

"Peter, in theory if the pump's pressure is too high both bowls should overflow; but because the fuel will take the path of least resistance, if one of the bowls overflows first (because of float adjustment or whatever other reason) the pressure may not be enough to make the second one overflow.

Regarding the sight glasses, my 4150 Holley does not have them installed, but I believe they are an option to replace the threaded plugs that go on the side of the bowls, so that you can see the level of fuel and adjust it without removing the plugs."
 
"Peter, I had this exact probl

"Peter, I had this exact problem last summer after installing a brand new engine with a Holley carb and electric fuel pump.

This is the engine I installed: http://bpi.ebasicpower.com/engines/base/350.htm

The first time I fired up the engine it ran great. The very next night, after work I fired her off again and it took forever to start, fell on its face and flooded out.

I called Indmar Marine and they told me it was the fuel pump and that they would ship me a new pump. While waiting for the new pump to come in I took a ball peen hammer and whacked the bowls of the carb pretty hard. I then cranked over the engine and it started and ran great.

This has happened one other time a few months later. I returned the unopened fuel pump to Indmar.

You might want to give this I try. I can appreciate how frustrated you are, trust me I have been there. Good luck."
 
"Hi
Same engine package but f

"Hi
Same engine package but from Michigan Motorz instead. Make sense what you are writing. One more question. How much fuel did you have coming from the over filling pipe? Mine was giving a 5-6 mm/ 1/4" thick fuel "flow", was yours more or less the same? My friend have a new fuel pump so I will perhaps try that one. Thanks for your help//Peter"
 
Fuel was coming out of the fit

Fuel was coming out of the fitting where the hard-line pipe threads into the carb. I also had a similar flow as you describe. You may want to try the tapping technique before you swap fuel pumps. You can also install a tee and a pressure gauage on the fuel supply line to read the fuel pressure and diagnose the pump.

I have an old Jeep (401 AMC w/ 4 barell) that occasionally stalls out. I've rebuilt the carb twice and still from time to time need to use the hammer technique. Good luck.
 
"Hi
New try today and worked

"Hi
New try today and worked fine......smacked the carb and run the engine for 15 min without any problems
happy.gif
Mike did your tempmeter and oilpressure gauges work like they should with the new engine? My oilpressure (same switch new location sits above the oilfilter)is high and the watertemp works good when ignition is on but very high when engine is runnning."
 
"Excellent! I'm glad for y

"Excellent! I'm glad for you Peter. The oil pressure on my new engine runs much higher than my old engine (she was 28 and tired though!). At idle I run 40-43 psi and at cruise (3100 rpm) it holds 65-75 psi. When I first started my engine I found the water temperature to be high, >150F. I found the cause to be inadequate water flow through the ear muffs. These engines are fairly high performance and require a good amount of water. My 5/8" garden hose could not keep up. Try using a short length of hose and connecting the water to the backside of your oil cooler. I use a patch hose to transition diameters. This works well for me and the engine hold 135-40F consistently.

I am not sure what you mean by "the watertemp works good when ignition is on but very high when engine is runnning." Do you mean when the key switch is in the ON position but the engine is not running?"
 
Hi
Thanks for your help both

Hi
Thanks for your help both Mike and El Pescador.

Have started the engine several times now and starts very nice every time.
I did have ground problem to the engine panel so when I measured from +12V to ground did I only have 9V. Grounded the panel together with the rest of the electrical switches and the oilpressure and watertemp workes fine//Peter
 
Back
Top