Honda 20hp, no spark

[One Tough Pressure 580]

I have a Honda 20 hp that will not start. I have it narrowed down to no spark, but have no clue after that.

Everything else seems fine, have gas, oil level is good, ran machine for 3 hours yesterday and no problems.

[Russ Johnson 141]

Here's a view of the GX620 crankcase. #9 is a low oil shut off switch, #10 is an oil pressure switch. Depending on which configuration you have, locate the switch, disconnect it, and see if it will start.

[beyoungsr 14]

OTP,

Not sure if the 20 HP HONDA is affected but, the 11 and 13 HP can be shy to start if they are placed in severe angles.

The angle makes the switch see a low pressure condition.

you might look for info here if this works

http://www.perr.com/forum/

[RyanH 14]

OTP,

Not sure if the 20 HP HONDA is affected but, the 11 and 13 HP can be shy to start if they are palced in severe angles.

The angle makes the switch see a low pressure condition.

Still a result of the low oil switch. The oil gets away from the switch, the machine "thinks" that the oil is low, so the circuit is not connected.

[One Tough Pressure 580]

Russ, thank you for the pic, will try it as soon as it is late enough to make some noise. So the oil switch is related to spark?

Do you know what the white plastic thing with three barbs is? It is located right behind the black cover near the choke and idle control. I am guessing it is part of smog.

The fuel lines runs to it, and then from there it goes to the carb and there is a return line from the carb.

Bruce, I have experienced some stalling at extreme angles in the past, but currently it is parked at home where it always runs fine.

Thank you both for your thoughts on this.

[beyoungsr 14]

OTP,

Good luck! I know what you are feeling!

[Russ Johnson 141]

Yes, the switch grounds the magneto coils so the engine will shut down in case of lack of lubrication.

The white thing is probably the fuel pump. Retrace the lines..from the gas tank, to the carb, and to a crankcase vent for vacuum.

[Scott Stone 604]

Umm, check the oil??? Some of the Hondas are reall sensitive to oil levels.

[One Tough Pressure 580]

I went out this morning and it fired right up. Pissed off the neighbor even though I waited till 8:30. Damn some people are sensitive.

Anyway, I did not change anything from yesterday, just turned the key. I did check the oil again before I started and all was fine, but I smell carb cleaner in it. I sprayed a bit in the carb yesterday when troubleshooting as I thought it was a fuel problem to start. What would cause either carb cleaner or gas to leak into the oil? I would guess worn rings, but this engine has less than 1000 hrs on it. It is draining, so I will see if that thnned out oil caused the problem.

The white thing does not have power or any mechanical ability to be a fuel pump. The fuel line goes from the tank to this gizmo and then to the carb, and the return line from the carb goes to it. Any front views of the engine and I can point it out.

[RyanH 14]

I had a problem with mine not starting. I traced the wires and they were all going to the right place. Problem ended up being a dodgy ground in the switch itself. Not I have to torque the entire switch slightly to make contact with the frame. Sometimes it's an effort to make the ground, sometimes it just happens to be in the proper place.

[Washaway 64]

We've all had our shares of grounding issues.

Has anyone ever considered running a #8 cable from the engine ground to a central location and having all your other grounds run to it. Kind of like the neutral cable throughout your house.

I've bought my supplies but haven't actually done the work yet.

[tropical wave 22]

I went out this morning and it fired right up. Pissed off the neighbor even though I waited till 8:30. Damn some people are sensitive.

Anyway, I did not change anything from yesterday, just turned the key. I did check the oil again before I started and all was fine, but I smell carb cleaner in it. I sprayed a bit in the carb yesterday when troubleshooting as I thought it was a fuel problem to start. What would cause either carb cleaner or gas to leak into the oil? I would guess worn rings, but this engine has less than 1000 hrs on it. It is draining, so I will see if that thnned out oil caused the problem.

The white thing does not have power or any mechanical ability to be a fuel pump. The fuel line goes from the tank to this gizmo and then to the carb, and the return line from the carb goes to it. Any front views of the engine and I can point it out.

Alan, if the rings were worn, the engine would burn oil and you'd get smoke out the muffler....more likely the valves or seals if your getting fuel into the crankcase, but with 1000 hours? I wouldnt think.....is the white gizmo a fuel filter ??

good luck with it

[Russ Johnson 141]

On Vanguards if the float valve in the carburetor doesn't close tightly, the gas gets in the cylinders then washes past the rings. All rings have gaps, and low viscosity liquids easily find them. This is not indicative of any internal damage or wear. Do you see your part in this pic?

[Washaway 64]

I think he was talking about part number 7.

Correction!! it looks like a 7 but infact it is 1 I was referring to.

[One Tough Pressure 580]

Do you see your part in this pic?

Yes, it is number one. Number 6 is my fuel filter, so what is number 21?

Wash Away, your a funny guy, with that reference to #7. I know a grommet when I see one.

I changed the oil, made triple sure it was perfect and I still get a intermittent bogging of the engine. I was unable to find the low oil switch, unless it is under the red front cover, which I did not pull off today.

[Russ Johnson 141]

#1 is the vacuum operated fuel pump. There are 3 different filter confugurations shown for various engine changes. If you have a #6, then you won't have #16 or #21.

The #9 oil level switch exits the engine block down near the starter, the #10 pressure switch will be on the left side of the engine near the crankcase cover.

[One Tough Pressure 580]

Vacuum operated fuel pump! Never heard of one of those, but that may be my problem. I had a huge water in the fuel issue back in early March and since I can not take the pump apart, have to wonder if maybe there is residual moisture in this item, or if it got damaged by the water. How much are fuel pumps?

I can not see a number 9 but there are some wires that go under the cover near the starter. I can feel a number 10 a few inches away from the oil filter, but due to mounting, can not get my head in there to see it. It does not have any wires coming off of it either. I will pull the cover later for a better view.

I also found a small hose, about 1/8" ID near the number 10 that does not go anywhere. Is there a breather in this area, or did something come apart?

You have been a great help Russ, keep it coming. Thank you

[Washaway 64]

Yes, it is number one. Number 6 is my fuel filter, so what is number 21?

Wash Away, your a funny guy, with that reference to #7. I know a grommet when I see one.

I changed the oil, made triple sure it was perfect and I still get a intermittent bogging of the engine. I was unable to find the low oil switch, unless it is under the red front cover, which I did not pull off today.

One Tough Pressure, I've corrected my previous post. Although I may be funny (or funny looking as some would say) I was referring to number 1 also......just mistook it for a 7. Eh!

As a matter fo fact it's exactly the part I thought you were referring to even before the pic was posted.

Any problems with it starting since you started this thread?

[Washaway 64]

Vacuum operated fuel pump! Never heard of one of those, but that may be my problem. I had a huge water in the fuel issue back in early March and since I can not take the pump apart, have to wonder if maybe there is residual moisture in this item, or if it got damaged by the water. How much are fuel pumps?

Get some STP fuel additive and put half the container into your gas tank. Further up north, where it freezes, they sell fuel line cleaners to remove moisture from your fuel system to prevent it from freezing. It will do the trick, if in case that is your problem.

[One Tough Pressure 580]

This thread started out because of my no spark, but that cured itself after sitting overnight. My current issue and an issue for a month or two has been intermittent bogging/lack of power at any given moment.

It is either a fuel or a spark problem, because even with the air cleaner removed for a test, it made no difference.

I can be running at full speed and then suddenly the rpm's drop to 2000 and it wants to die. I have talked to many people and they all are stumped. Russ has provided info here that noone else was able to. The local places that fix Honda, do not have any storage for my trailer and they insist that it stays overnight. Not gonna happen.

[Washaway 64]

This is easy....go and spend about 15 bucks on some spark plugs and fuel filters. Once you've changed them add the fuel line cleaner and you should be fine.

If it still does it afterwards, simply call Honda directly and speak to a engineer or tech support.

I do regular maintenance every 50 hours!!

Engine Oil

Pump Oil

Air / Gas / Diesel filters

Spark Plugs

My income is reliant on that machine and it's in my best interest to keep it running smooth.

I also add fuel additives to both my diesel and gas tanks.

[Russ Johnson 141]

Honda branded fuel pumps are extremely expensive. An aftermarket replacement is less than $20.00. The small hose you saw is probably the carburetor bowl vent.

There should be a number stamped on the block just below the starter. If you can get in to see it, get it for me. It will tell me exactly what configuration you have. Should look like GX620QAE2 or similar.

[One Tough Pressure 580]

This is easy....go and spend about 15 bucks on some spark plugs and fuel filters. Once you've changed them add the fuel line cleaner and you should be fine.

If it still does it afterwards, simply call Honda directly and speak to a engineer or tech support.

Plugs and fuel filter are both brand new. I even use a Racor fuel filter to see if there is any water in the gas.

I have put more ISO HEET fuel line treatment in latelyy than some have gas. Maybe I should just fill the tank with it.

Honda branded fuel pumps are extremely expensive. An aftermarket replacement is less than $20.00. The small hose you saw is probably the carburetor bowl vent.

There should be a number stamped on the block just below the starter. If you can get in to see it, get it for me. It will tell me exactly what configuration you have. Should look like GX620QAE2 or similar.

The only number below the starter is GCAD 2037447. Will the aftermarket pumps fit under the cover? What is the price on the real version by Honda?

[Russ Johnson 141]

The fuel pump for that engine really isn't too bad. $31.58. Honda part # 16700-ZL8-013

[Scott Stone 604]

You can also use a briggs fuel pump for a vanguard.

Now a problem that I had was it cutting out. I figured it was vapor locking, so I rerouted the fuel line up the right side, and put a hole in the side of the plastic to pass the line through. It is then a straight shot into the fuel pump.

Scott