1962 40 HP Johnson Electric SeaHorse Run number 2

I went through the carb again and now i can get it to idle and throttle up but i have no high RPM under a load. It sounds like it is really struggling to move the boat. It makes no differance if i have the choke on or off. it is still the same. In neutural it will rev. but has poor throttle response. Any suggestions. low speed needle is 1 and 1/2 turns out. it has an automatic choke and no high speed needle to set.

 

I still sounds like the idle transfer circuit. These are the ports that uncover as the throttle butterfly opens and the associated passages and idle fuel restriction/jet.

Does it have new plugs in it?

jim

 

The idle transfer circuit is clear i hosed the hole thing in carb clean and then blew it all out with my air compressor. I could see plenty of carb clean coming from the holes as i sprayed through them and i got out a lot of dirt. The plugs are old and i know i should change them anyway. What do you think about the points and coil packs under the fly wheel? Or do you think it could still be carb related?

 

I had a 115 Yamaha here that I did a total ignition system check on. I was convinced that the problem was ignition.

It was the idle transfer circuit as usual. That particular motor has very small passages.

I sold it to a friend that makes his living working on outboards. He is very good, but he let it sit and cleaned the carbs 4 times before he finally listened to me about that circuit.

You do need new plugs and it could be the points etc. If it has a power pack, that can make it intermittent at high speed. My money is still on the carb. It sounds like you cleaned it right.

Here is what happens: The gas sits in the float bowl and evaporates leaving a residue. The idle fuel pick up sticks down in the fuel in the bowl. Some residue is left inside this passage. I have a set of 60 through 80 numbered drills. Sometimes I have to use one of them to dislodge the residue. I don't use the drill end, rather the plain end so as not to damage the jet. It that jet or passage has just a little residue in it, the engine may idle but there is insufficient flow to support the more fuel hungry transfer circuit which is also fed through that jet. The result is that the engine does not want to come off idle with a load on it. It may come off idle a little bit, but the purpose of the idle transfer circuit is to get the engine spinning fast enough for the main circuit to kick in.

Also, it the lines and filter are old they may be shedding junk that can get in there. I run a spin on filter/water separator for this reason.

Are you running gas with ethanol in it? It makes the situation worse. It cleans the junk out of the tank and lines and sends it right to the carb.

jim

 

Jim is right on. I've had carbs on all kinds of engines give me fits after they have sat around with fuel in them. Anything from snowblowers..weed wackers..emergency generators...mini bikes..lawn mowers, they all gum up if left to sit too long. I've tried every brand spray carb cleaner on the market and found the best product to use is Gunk Hydroseal. It comes in 1 or 5 gal. cans and is a chemical which has a water barrior sitting on top of it. Be careful..as it's wicked stuff. The entire carb has to be taken down and all parts soaked over night...flushed with clean hot water , and then blown down with compressed air. I use a small torch tip cleaner to push through the passages, and then carefully reassemble. (Note Some of the newer off shore carbs are coming with plastic needle valve seats in them. These can not be used with the Hydroseal type cleaners as it will melt the plastic seats right out of them.

Bob

 

Bob,

We just started getting the 10% ethanol this year and it is killing small engines by the dozen. Here is what a I have done.

I test the fuel when I buy it for alcohol content.

I mix up only 1 gallon at a time for all my power tools.

At the end of each work day I pour the fuel in the tool back into my 1 gallon sealed can.

I start the tool and let it run out at idle.

The fuel will last pretty well in the sealed can just like in your fuel injected car sealed tank.

I fuel the tool up at the next use. So far they start up like a new one.

jim

 

On the boats we are considering making a fitting to put a balloon over the tank vent and installing a fuel shut off valve in the line. This essentially seals the tank from the atmosphere. If the engine is carbureted, there is still the float bowl to be drained.

I just drained the whole system on my boat for the year.

jim

 

Has anyone heard if any of these fuel additives to "counter" the negative effects of ethanol are worth using?

I see these additives being promoted all the time. Does anyone use them?

Kevin

 

Kevin,

The E10 or 10% ethanol fuel presents a problem down here in the heat and humidity that you may or may not face. You can read about it on the net. The ethanol has an affinity for water and will absorb it from the air in a vented tank. When it reaches it's limit on the amount of water it can hold, it phase separates from the gas and goes to the bottom, and for some reason retains some of the oil if it is premix.

In this situation, when you try to start up all you get is an alcohol and water mix since it is at the bottom.

If you want to see this, put some gas or premix in a clear bottle and add water. You will see the phase separation. According to the research I have done, nothing will prevent this. It would be easy to test an additive with the bottle test.

jim

 

Ok I did it again, took the entire carb apart for the third time and I hope I got it all this time. I can start it but it will not idle. Fuel is now coming from the mouth of the carb when i pump the ball or just keep cranking on it. Is this normal? I did check to make sure that the float was set correctly (even with the base of the carb when held upside down) before i put it back together. Idle needle is one and one half turns out. Also will now only start if the choke is off. Sound like too much fuel to me, or could it still be a spark issue?