Running on one Cylinder

[washita]

gotta love the welders dance hired a "certified welder" turned him loose on a overhead welding project with arc welder, a berry the size of a gumball dropped down his shirt and proceeded to the belt line where it continued its journey down to his sock, wow!!!!! what a incident/safety report that was to write up, all in all everything healed ok

 

[BobRip]

Well, I had more running on one cylinder today. This time I had no spark on the cylinder that was not firing. I replaced the coil with an earlier version coil that I had, heated the plug with a torch to burn off the gasoline and let it run. It did take a couple of minutes to start running on both cylinders, but it ran fine while I mowed. So my guess for the initial problem on this thread is that the coil was intermittent and finally failed completely. I also had some problems last Friday, but it cleared up after awhile. Hopefully I have the solution now. I will order a couple of coils tomorrow to keep as spares. Any comments would be appreciated.

 

[washita]

I wonder if you have a hair line crack or a stress crack in the coil had a ford that would lose spark due to a internal crack it would stop throwing a spark a very frustating intermittent problem, my 425 loads the plugs and runs on one cylinder if I let it idle for more than ten minutes the motor has 160 hours and a second set of plugs, problem not as bad since muffler has been replaced

 

[BobRip]

I wonder if you have a hair line crack or a stress crack in the coil had a ford that would lose spark due to a internal crack it would stop throwing a spark a very frustating intermittent problem, my 425 loads the plugs and runs on one cylinder if I let it idle for more than ten minutes the motor has 160 hours and a second set of plugs, problem not as bad since muffler has been replaced

Possibly that. At least it's not intermittent any more. Those are the worse kind of problem.

 

[BobRip]

Had a no cold start problem today. I figured it might be the fuel solenoid even though it clicked when I turned the key on. I pulled the air cleaner and it was very dirty on the outside of the carburetor. I started to clean the area and suddenly heard a click and saw the choke close. Evidently it was stuck open. I tried starting the engine and it fired right up. I then cleaned the rest of the carburetor outside, and then pulled the fuel solenoid and cleaned it. The engine ran fine all day with several hours of gravel hauling. I did have one engine cutoff. When I checked the fuel filter it had some air in it. I held it vertical and the filter filled with gasoline. It ran fine after that. This sounds like vapor lock. The gas tank was down to about 2 inches of fuel. Any comments on this. Lots of little problems lately, but they don't seem to stop me long. I have 827 hours on the engine, and have never cleaned the outside of the carb.

 

[ldabe]

Not sure BobRip,
But I think there is something to letting the fuel get down to low. Seems like mind does funny things to when I let the fuel tank get to low.

 

[BobRip]

Not sure BobRip,
But I think there is something to letting the fuel get down to low. Seems like mind does funny things to when I let the fuel tank get to low.

I agree. Especially if the engine is hot. It stands to reason that vapor lock is not as likely to happen if there is more pressure at the filter and pump inlet.

I had another choke failure to close this morning. I forced it closed and did my work. Then I removed the choke plate by taking out the 2 Philips head screws. I then pulled out the choke shaft and cleaned it and the holes it goes in. It seem to work smoother after reassembly. We will see how is goes tomorrow.

 

[BobRip]

I agree. Especially if the engine is hot. It stands to reason that vapor lock is not as likely to happen if there is more pressure at the filter and pump inlet.

I had another choke failure to close this morning. I forced it closed and did my work. Then I removed the choke plate by taking out the 2 Philips head screws. I then pulled out the choke shaft and cleaned it and the holes it goes in. It seem to work smoother after reassembly. We will see how is goes tomorrow.

OK, the choke worked fine this morning. Cleaning the choke shaft and the holes it runs through while disassembled worked.

 

[ldabe]

"Cleaning.....worked."

Yes! BobRip, always nice when the labor applied is not for nought, congrats.

 

[BobRip]

Well had another problem yesterday. When the fuel is low it would die after a few minutes of running. I had replaced the fuel pump recently and did not think that could be it. I checked for blockage in the lines, tank outlet, and filter and eventually put the old fuel pump back in. Now it's working OK. I ordered a new fuel pump today. I hope this is it. I really did not know how to test this pump, but when I blew air into the outlet with my mouth air came out the inlet. It sound like the check valves are bad.

 

[ldabe]

BobRip,

Here is some info I received the other day that I put on my Thread, 422 eng. problem..AGAIN-

"I spoke with a man who works on small engines in another state, and he told me that Robin and Honda engines with the "pulse fuel pump" are known to have issues with pin holes in the diaphrams. He said he has changed 3 pumps in the last two weeks. Also said that B&S makes the same pump for about half the price.

So, I am hoping that changing that pump next, will do the cure."

I am going out today to try and find a new fuel pump.

Where did you get you "new" one? Price?

 

[BobRip]

BobRip,

Here is some info I received the other day that I put on my Thread, 422 eng. problem..AGAIN-

"I spoke with a man who works on small engines in another state, and he told me that Robin and Honda engines with the "pulse fuel pump" are known to have issues with pin holes in the diaphrams. He said he has changed 3 pumps in the last two weeks. Also said that B&S makes the same pump for about half the price.

So, I am hoping that changing that pump next, will do the cure."

I am going out today to try and find a new fuel pump.

Where did you get you "new" one? Price?

I got it at Continental Engine. It was around $41 plus shipping about $7. I got some carb gaskets which I don't plan to use at this time. Their telephone number is 800-922-5632. I found that the engine would run if you fill up the tank (at least on mine) since the gas level is higher than the carb in this situation. If you blow into the fuel pump outlet and air comes out the inlet then the pump is bad. I don't know if it is good if you cannot blow through it. Does gas flow out of the pump inlet hose when disconnected from the pump?

I looked for pinholes and did not see any. It looked like the check valves were not closing.

 

[ldabe]

Not sure about the "blow and flow", but I talked to the place that I bought my Ariens zero turn (B and S eng.) a few years back about the "pulse fuel pump". There is one exactly like the one on my PT that is also on my Ariens.
Prices: $19.95 - $56.00!
The lowest priced one he was ordering from Honda!
Unbelievable price differences! The guy said he could not believe it either, and that he never noticed such a difference before, especially seeing they are the same part.
I don't know what PT is selling them for, but I am learning to "by-pass" Power Trac for any parts if at all possible.

 

[J_J]

I am curious why you guys think the fuel pump has anything with the engine running on one cylinder. Whether you have a good supply of fuel, or not, both cylinders get the same amount. If one cylinder is not firing, that is electrical. If you have replaced the coil, and plugs, don't know what else could cause the trouble except a weak magnet, if that is what it uses for the spark generation. Does that flywheel have two magnets. Clean them both with sand paper/emery paper.

 

[BobRip]

I am curious why you guys think the fuel pump has anything with the engine running on one cylinder. Whether you have a good supply of fuel, or not, both cylinders get the same amount. If one cylinder is not firing, that is electrical. If you have replaced the coil, and plugs, don't know what else could cause the trouble except a weak magnet, if that is what it uses for the spark generation. Does that flywheel have two magnets. Clean them both with sand paper/emery paper.

I don't think the fuel pump has anything to do with running on one cylinder. I should have broken this into two threads. The bad coil and fuel pump caused two separate issues. Sorry for the confusion. The fuel pump caused the engine to stall at low fuel levels in the tank. It might have been bad for awhile since I tend to keep the tank pretty full. Thanks for bringing this up J_J.