michealbernal Posted October 8, 2018 Share Posted October 8, 2018 Thanks to everyone's help I got the Marvel carburetor on my 1928 Standard rebuilt and installed. It ran great for a while but now it has started flooding. After I start the engine it immediately begins to run rich until after running about 20 seconds it stall out. A that point fuel is dripping from the air intake. I tried readjusting the float level but that did not make any difference. The fuel level is not overflowing the float bowl. I tried closing down the needle but that didn't seem to make any difference. Can anyone provide insight into what the issue might be? Any insight appreciated. Today I got a chance to work on my carburetor issues again. I removed the float bowl cover and turned the float level adjustment to the end of its travel. That left about 1/4 inch of fuel in the bottom of the carburetor fuel bowl. I started the engine but it immediately flooded out with fuel running from the air intake. The vacuum tank seems to be working properly in that it is pulling fuel from the fuel tank and delivering it to the carburetor. Is there some kind of test to do on the vacuum fuel system? I wish I had Supermans x-ray vision so that I could look inside the carb. and see where this fuel is coming from. Since that probably is not going to happen can anyone provide any insight into what might be going on here? Link to comment Share on other sites More sharing options...
JFranklin Posted October 8, 2018 Share Posted October 8, 2018 I don't know your carb but I would suggest to make sure the float needle is sealing in the seat and the seat is properly set in the carburetor. If so you should make sure the float is not filling with gasoline or hanging up on its pivot. Don't be concerned with the vacuum tank, it is doing its job or there would be no flooding. I would set the float level as specified in the manual. Good luck and give us followup. Link to comment Share on other sites More sharing options...
Leif Holmberg Posted October 8, 2018 Share Posted October 8, 2018 Fill up the vacuum tank,remove and tighten the vacuum line between the vacuum canister and the inlet.Start the engine and see if it still floaded.If not floaded the problem is the vacuum canister,a very common problem on 1920s Buicks.There can be a lot of different problems inside the canister.But no problems to open it up and take a look ,just remove all the skrews on top and lift it up. Leif in Sweden. Link to comment Share on other sites More sharing options...
Mark Shaw Posted October 8, 2018 Share Posted October 8, 2018 10 hours ago, michealbernal said: I removed the float bowl cover and turned the float level adjustment to the end of its travel. What are you adjusting for the float level? Link to comment Share on other sites More sharing options...
Leif Holmberg Posted October 8, 2018 Share Posted October 8, 2018 You have to bend the brass "rod" on the float bowl. Leif in Sweden. Link to comment Share on other sites More sharing options...
bigvic Posted October 8, 2018 Share Posted October 8, 2018 Hello if you haven't bent the float rod, I would suspect a saturated float or a bad needle valve/seat, seal. Mark Shaw has a great idea how to update/seal the cork float for the new (rotten) gas. As far as the seat/needle valve, I would remove the brass supply line to the carb after you drain the bowl and find a similar hose barb fitting and screw it into the bowl. Then attach some tygon hose to the barb fitting, now gently blow into the hose and see if the seat/needle stops your effort. Good Luck Link to comment Share on other sites More sharing options...
Mark Shaw Posted October 8, 2018 Share Posted October 8, 2018 1 hour ago, bigvic said: Mark Shaw has a great idea how to update/seal the cork float for the new (rotten) gas See photos below. I also suggest coating the entire cork with Krazy Glue or Airplane Dope to protect the cork from alcohol fuels. Greg Lang and others also sell foam float material if you don't drink wine. Install the new float and make sure it operates throughout it's moving range without touching the sides of the float bowl. Bend the tang to adjust the float level just below the tallest jet. Set the big air adjustment knob at the end of the ratchet tang & open the gas adjustment 1.5 turns. Start the engine and allow it to warm up. Adjust the air knob in an out and set it mid way between where it starts to run rough. Throttle up and re-adjust the air until it no longer stumbles. Take a test drive to see if it attains 40-45 mph. If not, just open the gas adjustment 0.25 turn and check the air adjustment again until it does. Good luck! 1 Link to comment Share on other sites More sharing options...
Steves Buick Posted October 8, 2018 Share Posted October 8, 2018 I agree with Marks post 100%, one thing I do is make sure the float is balanced so there is no sideways or lateral binding, drop it in water after you fuel proof it. You may try putting your old float in a cup to see if it sinks at all after 30 min. make sure low and high speed jets are not blocked. good luck.. 1 Link to comment Share on other sites More sharing options...
michealbernal Posted October 9, 2018 Author Share Posted October 9, 2018 Today I found that at least part of the problem is due to a leaking fuel flow needle valve. Is any one out there reproducing them? Is there a source of good used needle and seats? Link to comment Share on other sites More sharing options...
Mark Shaw Posted October 9, 2018 Share Posted October 9, 2018 The gas adjustment is a needle valve has a packing nut that probably needs to be tightened to stop an external leak. If you cannot stop the leak by tightening the nut, it may need a new piece of leather packing that you can make yourself. Link to comment Share on other sites More sharing options...
michealbernal Posted October 12, 2018 Author Share Posted October 12, 2018 I suspect that the float is at least partially saturated. I ordered a replacement from "Bobs" today. We will see how that works. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now