It would seem my fuel pump died LT15go

Brad_bb · March 17, 2024, 09:39:18 PM

2014 LT15go. 19hp Kohler CH620

This sane scenario has happened about 2 other times in the past. I haven't run my mill for 3-5 months. I use non-ethanol fuel.

Went to start the mill, full choke(It's 39 degrees) it fires right up, but as it idles, it start stumbling and dies. Start again and it fires up pretty quickly with full choke, which I quickly push it back in. Same thing, as it starts to idle, it gets slower and start stumbling and dies. Third time it's a little harder starting but fires up and samething. Now I try to start and it does not fire. No matter if I choke it or not, it does not fire. I try and try, but no dice.

Like I said this has happened at least 2 times in the past, usually when the mill has sat for awhile. The mill is indoors. The solution the first time was let it site for 5-7 days and crank and crank and finally it starts firing.

I know better such that when it stumbles on start up like that, If I give it part throttle to get the RPMs up, I usually have to immediately back off the throttle and let the engine catch up, and then give it a little throttle to get the rpms up and then go to full throttle. Then I can let it idle and it won't die.

So I first pulled the plugs and they looked good. It was not flooded. I checked both plugs for spark and all was good. So I suspect that I'm not getting fuel.
rwoelk suggested I look at the fuel pump. So I pull the hose going to the carb and crank it over to see if the pump i sending any fuel. NOpe. Then I pull the fuel supply hose and crank it over to see if I can feel any suction from the pump. NOpe. So now it's either the pump, fuel filter, or an air leak in the fuel supply hose. I had that problem in the past from a cracked fuel line where Woodmizer had the hose coming out of the fuel tank and then bending 90 degrees downward. It was cracked at the bend from fatigue. This time though I thoroughly inspected the lines and all was good. I had fixed the fatigue issue by adding a 90 degree elbow fitting in the line to eliminate the stress being put on the hose. The fuel filter was relatively new so I really don't think that is it. That just leaves me with the pump. Taking a picture I noticed signs around the fuel pump that fuel had been leaking and sawdust was sticking the liquid and remained after the fuel evaporated.

So now I need a pump. Oem? Aftermarket? Is one brand better than others?

Dan R · March 18, 2024, 01:26:34 AM

Brad,
On my LT 15 with the 19 hp Kohler I put a ball pump in line like a outboard has. Give it a few squeezes and it starts right up. Mine just needed a little shot to get it going.
Dan

ladylake · March 18, 2024, 03:44:35 AM

Get yourself a Carter p60430 from Amazon or ebay, that is a rotary vane pump which should last for years. The pulse diaphragm type dont last on a mill. Get rid of or plug that engine mounted pump as they can dump gas into the oil when they go bad. Steve

Chuck White · March 18, 2024, 08:02:46 AM

I bought one like the one in your pic from the John Deere dealership about 5 years ago, cost around $30.00, and easy to change!

Ben Cut-wright · March 18, 2024, 01:24:46 PM

So this is at least the third time the fuel flow problem has occurred?

You replaced the pump the first two times?

You don't say if fuel flowed from the tank when you took the pump inlet hose off?

Do you shut the fuel off when not using the mill?

The witness stains indicate that fuel is escaping, possibly from the pump or lines. A diaphragm pump left dry often causes the valve tips to harden and fail to seal until fuel wets them again. If you shut the fuel supply off or the tank can't provide positive flow to the pump, then have a leak that dries out the pump, or the pump sits long enough to evaporate all the fuel, the valves will get dry and stiff.

The suggested "ball pump" is a good simple solution if a dry pump diaphragm is the problem.

Brad_bb · March 18, 2024, 11:24:14 PM

Picked up the mill in 2014. Had a cracked fuel hose in about 2017. Fixed that. Had original fuel pump go bad in about 2021. Now this pump has failed.

There is no manual fuel shut off.

When you disconnect the fuel inlet line at the pump, no fuel flows. I think it needs some suction from the pump to get it flowing. It has the pull the fuel like a siphon I think to get it started and it has to also go through the fuel filter before it reaches the pump.

Sod saw · March 25, 2024, 07:57:51 AM

.

Brad, I have an inline 12 volt fuel pump sitting on top of my fuel tank with wires running to the engine. It is not a factory item but was added by an owner before I picked up the mill. A couple of rubber straps hold it In place.

When I turn on the key to start the mill I can hear that pump so I am sure that it is working. Once, one of the wires came lose and it made no sound and the mill would not start.

With the pump so close to the fuel, the suction hose is also very short.

Just a thought.

.

Brad_bb · April 01, 2024, 10:42:22 PM

Please bear with me: So it took almost a week and a half to get a new fuel pump. Woodmizer failed me. I was just writing what happened but then figured why waste your time. Sufficed to say, they had the part in stock at their plant an hour away and never sent it up for a week, blamed their computer system, then was told it would be in the next day and it wasn't and of course no one calls you and feels responsible despite knowing you've been down for 8 days for something had I known, I could have ordered one from Amazon and had it here next day. After multiple chances, waiting on hold numerous times, getting dumped to voicemails, and having their system hang up on me so I could start over again.... I canceled the order and ordered the one from Amazon and had it at lunch time next day. Did I mention that none of the 3 people I dealt with at woodmizer had any empathy nor gave any apology whatsoever?!

Now that I've vented....

I put the new pump on and cranked, and nothing. Still seemed like I was not getting fuel.

My first thought was: I the fuel shut off solenoid keeping fuel from flowing? I quickly pulled off the air cleaner and pulled the 5 screws/bolts for the top plate over the carb. I didn't remove the 2 rubber tubes but just pulled the plate back enough to have a good view of the solenoid, which was at the front side of the carb/engine. I turned the key on and thought I heard the solenoid click. I put my ear to it and turn the key on and off several times and I could definitely hear good movement of the solenoid shaft. Then I asked myself If the new pump was pumping anything.
I pulled fuel hose off the pump going to the carb and cranked. Fuel should come out, but there was nothing. This tells me the problem is the pump, the fuel filter, the fuel line, or the bayonet fitting at the tank or the pick up tube in the tank. I pull the engine vacuum hose and crank and I can feel vacuum. I then pull the fuel supply line to the pump. No fuel drips there. I go up to the bayonet fitting and the tip is dry, it hasn't pulled any fuel out of the tank. The spring loaded shut off pin in the bayonet fitting works. I've actuated it.

I then inspect the fuel line carefully. I have two plastic fittings in the line, a 90 degree elbow that I put in to relieve the stress on the hose from the original configuration. I also have a union because when I cut the hose originally for some reason it was too short and I had to add some length....instead of buying another longer length of hose I just put the plastic connector in with a short piece I had. I inspected the hose carefully and couldn't find any problem. The fuel filter is not old and low hours so I had a hard time fathoming that it could be plugged. I figured that I should be able to siphon fuel down to the fuel pump by sucking on the line that goes into the pump. If I couldn't get fuel, that tells me I have an air leak somewhere, that the line to the fuel was not sealed.
So I really didn't want a mouthful of fuel so I carefully sucked on the hose suing only my mouth and what I could draw with my cheeks. I closed my throat and did not breath, so I could not draw fuel into my lungs or ingest it. I did about 3 sucks and got a dribble of fuel. It wasn't much, but one more suck got the siphon flowing. So I plugged it into the pump. I didn't get any in my mouth thankfully. As soon as I plugged it into the inlet, fuel started pouring out the outlet, so I plugged that line in. I had already reconnected the vacuum line.
So now I trued to crank it and it fired right up. I used some slight pressure on the engagement lever to increase the RPMs and let it run like that for 20-30 seconds and then let it idle. I then shut it off and restarted and shut it off. I had to go do a few things for a few hours, but then came back and started it again, fired right up. I made a single cut one the piece i had set up on the mill, and that's all I had to do for now and shut it down.

What did I learn?
Either a)the diaphragm pump needs to be primed
or b)The diaphragm pump is a helper for a siphon effect. It needs fuel in the line and gravity plus the pump to get the fuel flow going, and your fuel flow happens mostly due the siphon effect - gravity whereby the fuel source is higher than the carb and when allowed to flow does most of the work drawing fuel from the tank.

When I was messing with the fuel line after the original problem, It drained what was in the fuel line. Now a dry diaphragm pump with an empty line, cannot create enough suction to start the fuel up from the tank and into the fuel line.

I've not seen anyone talk about this. Am I right? Another disappointing thing is that there is no engine troubleshooting section for the mill engine in the binder that came with the mill. I looked and found nothing.

Ben Cut-wright · April 01, 2024, 11:58:13 PM

The pump you replaced might make a good spare.

A full fuel tank will require less siphon and provide some degree of positive force once a full hose is established. These pumps actually move a pretty good stream of fuel but...as you discovered, they preform much better at pumping than creating a vacuum. Most fluid pumps are that way.

a) of course it needs to be primed. A long empty fuel hose, filter, and low fuel tank will dramatically increase the amount of *cranking time for the pump to self-prime though.

b) Siphon effect not so much as maintaining capillary action of a solid fluid stream.

Brad replied when to my question:
"When you disconnect the fuel inlet line at the pump, no fuel flows."

After replacing the pump and cranking the engine Brad says:
"I then pull the fuel supply line to the pump. No fuel drips there."

After establishing a fuel flow in the supply hose a siphon effect was evident. At that point the fuel pump doesn't have to evacuate the entire fuel line. It will maintain a full hose unless a leak occurs or you run out of fuel.

(I've had better luck using the air my lungs to pressurize the fuel tank and fill the fuel line and filter. My stainless steel fuel tank has a 1/2" threaded pipe fitting plug in the top.)

Brad wrote:
"When I was messing with the fuel line after the original problem, It drained what was in the fuel line"

Not sure what you mean to say about the *timeline on the above.

Brad_bb · April 02, 2024, 12:24:26 AM

Quote from: Ben Cut-wright on April 01, 2024, 11:58:13 PMNot sure what you mean to say about the *timeline on the above.

When I first had the problem a week and a half ago and was trying to diagnose the problem, I had disconnected the bayonet fitting, dropped the hose down and depressed the spring loaded shut off valve in it and drained it into a fuel jug, the fuel that was in that part of the line which would have been 2/3rds to 3/4ers of what was in the line. I then emptied my fuel tank, and refilled it 1/3 full with newer gas just in case that was an issue. Later on when I disconnected that line from the pump there was some fuel that drained out. So by the time I put the new pump on, with all my messing around, the fuel line was empty.

Nebraska · April 02, 2024, 07:17:21 AM

You could put a squeezey bulb from a boat fuel line in the loop and prime the line, I know that doesn't correct the problem of the air leak but if the more stays running. Just a thought.

ladylake · April 02, 2024, 07:29:42 AM

Electric Fuel Pump CARTER P60430 Steve

Ben Cut-wright · April 02, 2024, 11:59:52 AM

Brad said:
"I put the new pump on and cranked, and nothing. Still seemed like I was not getting fuel"

Any sort of fuel pump has to create sufficient void (decrease of atmospheric pressure) in the inlet side of the fuel circuit to allow atmospheric pressure to fill the line and move liquid fuel to the pump. Loss of void during or between cranking (pump operation) will increase (the time to fill) or prevent the inlet side from being filled.

Using the engine starter motor for *extended cranking is very bad for the starter, short intervals risks loss of *suction side void. An *empty carb demands even longer cranking times to fill sufficiently and supply fuel to the engine. When the fuel line and the carb are *both empty the cranking time can be extreme. As you have discovered, either a technique to overcome the empty fuel inlet circuit must be employed, or the fuel circuit must be modified in some way.

Technique (in this instance) is cheap, easy, and readily available.

Brad_bb · April 02, 2024, 01:15:59 PM

I've run this mill regularly since 2014. Besides this time, it may have happened 2 other times. Given the infrequency, and now knowing what to look for and what to do, I don't think it's worth any modification such as an electric pump or priming bulb.

doc henderson · April 02, 2024, 04:04:23 PM

my TK has an electric pump that precedes the mechanical pump on the engine. It came that way but would be an easy mod.

Brad_bb · April 03, 2024, 11:41:29 PM

$40-$50 bucks doc, but I'll keep it in mind if I have any more problems.
I milled 4 small Ash logs this evening. Mill fired right up, no problems, except that the first two logs ended up becoming firewood due to bacterial rot. Two or three local sawyers I deal with don't seem to be familiar with bacterial rot. Maybe they're just not sawing any Ash. I took some pics of it in the logs tonight.

firefighter ontheside · April 07, 2024, 06:03:19 PM

Last year my mill woudn't start and I noticed there was no fuel in the filter. I figured it was the fuel pump. I took the fuel pump off of my lawnmower which has a kohler motor. Started right up. Went to autozone and bought 2 pumps, with one to have as a spare. Good to go.

doc henderson · April 07, 2024, 06:53:15 PM

Brad, mine is 24 bucks in the Amazon.

Post Winter Diagnosis. More than just a fuel pump. (forestryforum.com)

Brad_bb · April 11, 2024, 06:23:47 PM

I may end up going to Doc's solution quicker than I thought. So I've milled 5 or 6 small logs each of 4 days in a row. No issues until I was half way through a 10 inch cherry log. I was doing something like moving slabs out of the way or brushing off dust, and the idling engine started slowing down and then dies. It sounded like it was running out of fuel. The fuel filter was empty. There's usually some in it. I go take my slabs outside, sweep up some dust etc for about 15 minutes. I go back and there's a little fuel in the filter. It start up fairly quickly, I let it idle and after 10 or 15 seconds it chokes and dies. Fuel filter is now empty. I go and do some other things for 30-40 minutes (frustrated), start it again and it starts fairly quickly, I try to engage the blade and it hesitates at first but then catches up and I engage and cut for about 3 ft and the engine rolls back and dies. It's not getting fuel. I have just under half a tank of fuel. I ordered a filter but it won't get here til tomorrow(Friday).

I'm wondering if the pick up tube in the tank is clogged? Has anyone pulled the pick up tube out of the tank before?

Is the silver fitting threaded into the plastic or is there a nut underneath that requires a special tool? I want to pull the pick up tube and dump the fuel through a filter just to be sure. I want to eliminate all possible issues before I take the step of adding the electric fuel pump doc and others suggested.

Brad_bb · April 11, 2024, 06:43:31 PM

@doc henderson @ladylake is the fuel pump you're using the one that ladylake recommended? That Carter pump says "in tank". Does it need to be in the tank to disperse heat? or can it be in line?

StimW · April 11, 2024, 07:30:47 PM

Read through but didn't see this information.
These fuel pumps need a tight crankcase to provide the pressure-vacuum to work.
Check to see if there are lose bolts at gaskets.
My Grasshopper Zero Turn has a 20 hp Kohler with the same fuel pump.
A week ago when I started it for the first time this season I noticed the dipstick going up and down when cranking. I replaced the O-ring on the tube and it stopped doing it.

doc henderson · April 11, 2024, 07:48:46 PM

my tank does not move, so has a 6-foot section of hose from the tank pick up through the power chain, to this pump mounted to a flat plate that the engine is mounted to then up to the one on the engine (Kohler 38 hp gas) then it goes onto the carb. you are looking at the output side and the automotive style (used to be on the outside of many brands of carbs and cars) fuel filter in the picture provides the barb for the tank side input line. I also have seen the plastic inline filters, and they never fill s up with fuel. aggravating but they seem to work fine if only showing a 1/4th full filter. the plastic one is between the two pumps.

doc henderson · April 11, 2024, 07:57:39 PM

Just need a hot wire that only is hot when the key is on. It is ok to turn the key to on and wait a bit for this pump to prime the other. I had to pour fuel into the line after working on this one but have never had a problem. the old one is working fine. my issue was low oil level. I got the parts and will replace the lines and filters. I think my draw tube goes through a rubber bung into the tank. and presses in.

Post Winter Diagnosis. More than just a fuel pump. (forestryforum.com)