Heavy carbon fouling

[JimHo]

I tore my Genoa on Sunday, and ended up motor sailing about 24nm back to the mooring with the main up.

Everything was running fine. Engine temp was lower than usual at 120-140. Throttle was 3/4 or less. I was running with the waves which were about 3-4 feet so a relatively smooth ride.

Before leaving that afternoon, I had added 10 gallons of fresh gas to the 8-10 gallons in the tank. All the gas in the tanks came from local gas stations and was 87 octane.

I have the Indigo EI unit, and new this year Champion RJ12C plugs. I also replaced the exhaust hose directly after the water entry fitting last winter.

On Monday, I started the engine. It was a little hard starting, but caught. I went to put on fenders and dock lines, and I could hear the engine sputtering. I looked overboard and there was a 6' round puddle of soot floating on the water. I didn't see any smoke in the air. I shut the engine down, and pulled plugs. All were fouled with a greasy soot, and the #4 plug's gap was completely obstructed.

I cleaned the plugs and she started but had no power and would stall when put into gear regardless of RPMs.

I'm heading back out tomorrow to try fresh gas from a can with some Marvel Mystery Oil; and a new rotor, cap and wires. I'll also change the oil with SAE 30.

Is there anything else I should do while out there?

Thanks - Jim

[W2ET]

Long shot, and the experts will be right behind me, but is there any chance you got diesel instead of gasoline?

Bill

[JimHo]

Good thought - but no. I go to the same gas station for my car.

The engine seemed to run fine all the way back to the mooring -about 5 hours. I think diesel would have sunk to the bottom of the tank, and been picked up during that run.

[Dave Neptune]

First thing do not add any MMO to the gas yet as it will make it worse.
Check to see that the choke is working properly in both directions so you know it is open when running.
Check the C-advance to be sure it is working smooth in both directions (advancing and springing back). Also be sure you have a crisp blue spark.

You say you changed the exhaust hose, was it plugging up or cracked? Usually the hot section is replaced two or three times before needing to replace the hoses. The hot section is where the exhaust plugs up and it can cause fouling as well as a loss of power.

Also be sure the "spark arrestor" is clean for good air flow?

Dave Neptune

[JimHo]

My hot section was an iron 4" pipe coming off the exhaust flange into an elbow with the water entry. The iron pipe had rusted, and I had to remove the hose to get the whole thing out. The hose did look like it was collapsing, but that might have been damaged in the removal. the elbow was fine.

The new hot section is a wrapped stainless pipe to the elbow to the hose.

I'll definitely check the choke, but not sure what you mean by C-advance?

Thanks - Jim

[Dave Neptune]

The C-advance is in the distributor. To check pull the cap and give the rotor a twist. It should twist to a stop and return freely against it's idle stop smoothly. The C-advance is often over looked with an EI as you have no real need to check anything inside for many years however the C-advance should be lubed and checked at least once a year!!

Dave Neptune

[JimHo]

I looked it up real quick, and it looks like the centrifugal advance is a couple of weighted arms that rotate on a pin and held in with a spring. As the RPM's increase the arms stretch the spring and move outwards.

Is there ever a situation where you would need to clean in there because a varnish develops, and if so how do you clean it? Also, do I need to just lube at the pins? And finally, what's the best lube for that?

Thanks - Jim

[Dave Neptune]

A few drops of oil. You may still have a piece of felt under the rotor, if so it's purpose is to lube the advance AND the counter shaft that the rotor rotates on. The oil runs down and deposits on the C-adv mechanism and the centrifugal forces delivers it.

Use a thick oil 30~40 wt or if you find you need to remove to clean out rust use a light grease.

With the EI removal is pretty easy. Remove the cap and rotor, disconnect the harness to the EI unit and remove the 2 screws that hold the "point plate down" now the EI plate. NOW gently remove the plastic shutter by pulling up carefully so you don't break it. As you pull up the plate will come up at the same time until the photo cell can clear the shutter. The weights and springs are now exposed sot they can be serviced or removed easily still attached to the counter shaft.
Most likely all you will need to do is lube things up.

Once reinstalled the timing should still be the same as it was.

Dave Neptune

[JimHo]

Perfect - Thanks!

[JimHo]

Problem solved -the choke cable lever arm is slipping on the shaft, and is not opening properly.

Thanks for all the help