#26
IP: 155.186.122.195
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The emulsion well is in the middle of the float bowl. The fuel from the main jet feeds fuel into it and air is fed into it via vacuum and metered by the main air (corrector) jet. The chamber has a sealing surface that must be sealed by the bowl gasket. This seal is a must for good carb performance. This feature will not leak fuel into the throat though. Look to the float and or setting for that.
Dave Neptune |
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TimBSmith (10-16-2021) |
#27
IP: 209.6.152.28
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Emulsion tube...and well...
This is the emulsion tube in our gravity fed system. In our system it is called the main nozzle.
https://photos.app.goo.gl/XU8bALZcgDRTdjZK6 Clogged emulsion tube https://photos.app.goo.gl/ptiKSJpizGaX7Fht7 The fuel air mixing happens in the emulsion well into which our tube inserts and in the venturi. An important seal is on top of the emulsion tube/nozzle (a little round gasket) and between the top and bottom of the carb. What our diagram shows as Bowl Cover Gasket. I actually put mine on inverted first attempt. Check your emulsion tube carefully because that was where my great blockages were. https://photos.app.goo.gl/vdYbMDM7wex28QqKA Lastly From my reading....how the nozzle/emulsion tube functions... Emulsion Immersion. You'll see references here to emulsion circuits, an important-sounding term that describes mixing fuel with air. Think of it as blowing bubbles in the fuel. All carburetors mix air with fuel in the venturi just before it enters the engine. But carburetors also mix air with fuel farther upstream inside the carburetor in the main well to make the liquid fuel easier to manage. Last lastly really. I also remember reading and being told here to make sure the main jet gasket is seated carefully and that the main passage plug gasket is seated carefully or there can be pooling in throat from fuel pressure leak. Others can clarify. I am still learning and don't want to range to far out of my depth.
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Tim Smith Oasis Pearson 30 1974, Number 572 Boston, MA USA Last edited by TimBSmith; 10-16-2021 at 11:10 PM. Reason: clarity. |
#28
IP: 104.174.83.118
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Maybe I missed something but reading through this thread the only issue that's been found and resolved so far is fuel pressure. Coil input voltage is still suspect as is carburetor integrity, spark and fuel quality. The burnt smell that started this off could be attributed to the fuel pump damage but with replacement of the fuel pump that's been handled. Distributor timing is low on the list because it has not been disturbed since the engine was running properly. Firing order has been mentioned more than once and is so easy to check it should have been done long before now.
So where are we?
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others Last edited by ndutton; 10-17-2021 at 12:27 PM. |
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Sam (10-18-2021) |
#29
IP: 47.18.111.244
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It took me a while to act on the suggestions. I started by charging up my batteries, which is really easy now with boat sitting on the hard. I went there today to test things Neil listed in his last post. I was also planning to run tests from Don's sudden shutdown troubleshooting video. But it turned it was not needed. The engine just started and run. So, not having adequate voltage on coil was the main issue. It is possible other factors may have been in play as well to make things worse. I was wrong to assume that if the engine was turning it was sufficient to have good spark. Many thanks to everyone for all comments.
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Alex 1976 Catalina 30 Perth Amboy, NJ |
#30
IP: 104.174.83.118
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As long as we're spreading around thanks
edwardc, post #21 in this thread.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#31
IP: 47.18.111.244
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Yeah I saw that. I thought the spark was good - blueish/white. My old batteries were always hovering around 12V, which I do know is low. But it did not prevent the engine from starting. I will run a wire from 'R' terminal to coil '+'. It is a very good idea. Thanks.
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Alex 1976 Catalina 30 Perth Amboy, NJ |
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