Dies after carb rebuild

In late November I rebuilt the carbs on my 1984 evinrude v4 140. After the installing it started right up on the muffs and seemed to run good. I have not had a chance to get it in the water til next week. So the other day I started it on the muffs and it ran good until I put the startup lever down. Once I put the lever down it dies. Any suggestions? The reason I rebuilt the carbs is because it was dying at idle speeds. Thanks.

Re: Dies after carb rebuild

idle speed set too low, what are your idle rpms. if it won't idle on muffs, it will not idle in the water. you have to set idle speed around 1,000 rpms on muffs, then fine tune the idle speed in the water.

the reason, on muffs, there is not any back pressure on the exhaust, when in the water the leg is full of water, and it requires more rpms, to force the water out of the leg, so the exhaust can exit.

disconnect throttle cable, adjust idle on motor, now reconnect cable, adjust cable to match the motor, not moving the motor linkage.

did you check compression? http://forums.iboats.com/showthread.php?t=313963&highlight=compression

Re: Dies after carb rebuild

There were no adjustments on the carbs when I rebuilt them. All the jets are fixed. The only adjustment I could find is the float level. Is there somewhere else to adjust the idle speed? Sorry for the ignorance? Thanks

Re: Dies after carb rebuild

In THIS DIAGRAM it is screw #75 (fitted to the spark advance lever #76)

Re: Dies after carb rebuild

Is that the screw that pushes the arm on the carb?

Re: Dies after carb rebuild

no, it is the screw up high that stops the linkage when speed is lowered. let me see if i can find a pic.

Re: Dies after carb rebuild

Thanks for the replys. I will run it again tonight when I get off work and adjust that.

Re: Dies after carb rebuild

See the thumbnail, which is more like the one you will be working on.

If you did not fool with the timing since or before working on the carburetors, I would not adjust it.

Take the air silencer cover off the carburetors and observe the throttle plates as you move the throttle through the full range from idle to WOT. The plates should be fully closed at idle with the warm-up down, and Horizontal (WOT) at the full throttle. The carburetors' throttle plates need to be 100% synchronized through the whole range of motion.

Idle should be adjusted after all other steps in the linkage and synchronization process, under load, in the water, with the engine warmed up and in gear.

Re: Dies after carb rebuild

Guys, those screws usually never go out of adjustment, but what is often over looked is the CAM FOLLOWER ROLLER. They become brittle and fall away. Some have a hard black roller and a clear plastic outer cover to this roller that will fall away. Check that first before you make any adjustments.

The cam follower is attached to the carb linkage and is the first thing to move when you advance the throttle. It rolls against the large cam piece as you advance throttle/timing.

Re: Dies after carb rebuild

Update: I finally got a chance to work on the boat today and found something interesting that I didn't catch before. I decided to replace the fuel filter and primer bulb as maintenance. I picked up a new 3/8 primer bulb and when I went to install it I found the old one was 5/16 with 1/4 in fuel line going towards the tank. I replaced the line with 3/8 all the way to the motor. What would this smaller hose done to how the motor ran?

We bought the boat in July and have never been too pleased with how it ran. I'm a bit cheap so I have been learning as I go fixing stuff.

After that I installed the new fuel filter, new plugs (just to be safe) and fired it up. Motor seemed to run pretty good. After it warmed up I lowered the warm up lever and it stayed running. I turned the the idle screw about a half turn and that sped up the idle just enough. I'm not sure of the RPM's because the tach doesn't work right, but I will tackle that another day. Thanks for all the replies.