Rude 140 Reed Problem?

[rtek816]

Hi all, 1986 E140TLCD. Rebuilt this spring has just over 100 hours. Everything had been working great. Spent 3 days trolling for salmon in NY and the end of the third day the engine started stalling at trolling speed. Took off the air silencer and the top port carb is spraying fuel back out the intake at idle. I took the carb apart again and couldn't find any problem. Float level is slightly low of level (thought it was a fuel level problem). I can see half of the reeds through the butterflies and don't see any contaminents. Does it sound like a reed is stuck open or broke? I did a compression test, 120,130,120,125. The 130 cylinder is fed by the carb that sprays fuel back. I put my hand over the carb throat and it pushes back and did backfire. The other three carbs just suck like normal. What do you guys think? Pull the reed plate?

 

[oldcatamount]

Re: Rude 140 Reed Problem?

Fuel being blown out of a carb throat is surely a sign of a bad reed, however, it's highly unlikely that's the problem. My suggestion is a complete re-build of that carb. Take out the welch plug and throughly clean the idle circuit with a quality carb cleaner and compressed air. How does the plug look on that cylinder compared to the others? (ps..any salmon?)

 

[rtek816]

Re: Rude 140 Reed Problem?

Oldcat,

Thanks for the reply. Wasn't a bad trip but I always expect better. Biggest one was 27#. No welch plug. Plastic carb bowls and bodies. I went through the entire idle circuit (plate and gasket on the side) and they are absolutly clean. I can swap the carb with the one below it to verify it's not the carb (they have the same jets). That cylinders plug didn't look any different from the others. Light carbon and not wet. Thanks, Bob

Update:
Swapped the carbs, same result. Tilted the engine up and heard a "ting". Found a phillips head countersunk screw on the lower cover. Item 18 in the breakdown. 1 of 2 that secure the reed plate to the manifold. Reed plate needs to be removed.

 

[boobie]

Re: Rude 140 Reed Problem?

You'll probably find the reeds and reed block okay. Back in those days the reed blocks would loosen up from the intake manifold because they weren't installed properly. When you put it back together install the gaskets dry, no sealer. Then put some blue loctite on the screws that hold the reed blocks on.

 

[rtek816]

Re: Rude 140 Reed Problem?

Boobie, I took the manifold off and both screws were out. I only found 1 of them. Looking into the internals there are no pieces of the gasket. Is it possible this was put together without one? I ordered 4 and will replace all of them and loctite the screws as you suggested. How can you not properly install these into the manifold? It's only 2 screws.

 

[boobie]

Re: Rude 140 Reed Problem?

In the old days OMC was putting gasket sealing compond on the gaskets when they were manufactured. After not to long a time the gaskets would get soft and the reed plates would loosen up. That's why you always put reed plates and intake manifold gaskets together Dry.