I went and started up the good ol' 1968 190XT (Series 2, I think) today to get some bush hogging done. It hasn't been started since this spring for plowing. I checked oil and all that good stuff, put in a fresh 20 gallons of gasoline. It started up just fine as it normally does, no issues at all. However, I noticed a fuel leak from what appears to be the fuel pump. I found what looks incredibly similar in the service manual (Page 194, see attached), but I believe it's a little different. The manual also says the G-2800 could have a carb, but it looks nothing alike. I will attach two images as well to show the component/leak.

When I first started it, the leak seemed like a lot. The radiator fan was blowing back against it and causing the fuel to spray all over, so it was very hard to decipher where the source was. I decided to at least let the engine warm up completely at idle (2,500 RPMs) before shutting it back off. Once it had run for about 15-20 minutes, I checked again and the leak was much less severe. I could also now tell that it was coming from what looks to be a relief hole in the lower-half (see attached). If I covered the hole, the leak would stop and the engine appeared to run exactly the same. This is where bad ideas happen.

I decided to plug the hole with some putty to get me through the brush hogging, and then I would dismantle it later and repair it properly. I went out bush hogging for over an hour with zero leaks or issues. Then I had a small hiccup in RPMs. It only lasted a couple seconds and went away. A little bit later the engine did more than hiccup and stopped. I shut it all off, turned off the PTO, etc. Restarted the engine and it idled just fine. I put it in gear to drive it back to the house and it died as I let off the clutch.

I am assuming these two are related. I currently have it sitting in the field. The putty is still in place and sealing the leak effectively - which I realize may be the cause of my current issue.

When I first started the engine today, it appeared the leak was from somewhere on the upper half of the fuel pump, but later, after it died down, it was only from this relief hole. Would anyone have any insight as to what the original issue was, why it changed as it warmed up, and why it shut down after over an hour of running hard?

Thanks!

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I've been looking into sourcing a new fuel pump and have found several replacements online, but a rebuild kit would be much preferred. Does anyone know of a rebuild kit for these that is still available somewhere? Or perhaps a cheaper electric fuel pump option?

EDIT:

So I walked out to the field and gave the engine oil dipstick a whiff. I would say it has a fuel smell. Guess I'm gonna give it an oil change and unplug my drain hole on the fuel pump.

Side note. I'm not saying it's a bad design, as I would assume there is a purpose behind it... But why does the fuel pump have a direct connection to the crankcase? Is it lubricated with engine oil as well, being a mechanical pump? I am ignorant on this design, but I do understand it's my own ignorance that has led to a bad decision.

Also. I see why the fuel pump is connected to the crankcase now... I was thinking about it and it then made sense why they have that arm sticking out of them, lol. My bad.

You're absolutely right, Lynn Marshall. I'm making a trip to town today to get supplies for two oil changes. I'm researching and trying to plan ahead for the pump, but that will only happen after it's running well.

On the topic of the fuel pump. The service manual says it runs at 5.5-6psi. I can find many electric fuel pumps that give around that, but of course they all have a range. 3-8 psi, for example. But even pumps that have nearly the same range have different GPH ratings. One gives 6gal/hour and another gives 25gal/hour. So this leads me to a few questions.

1), What sort of GPH should I be looking for?

2), Does the 190XT G-2800 have a fuel pressure regulator to help with the fuel pump not being set at a precise PSI?

3), I would assume opting for a max pressure that is slightly high is better than one that has a very low minimum, if I'm even given that choice. But any pointers on this?

Thanks!

Call Steve at B&B Circuits or see below:

Click on above and scroll down to the 6 hole diaphragm version like yours. You could send a question to the seller to confirm it will fit your 190XT. 

Just make sure you get the check valves around the right way when you assemble it - I've had to re-do a few pumps that folks have tried to rebuild and foolishly put both check valves in facing the same way.

As an alternative, you can just get a cheapo $30 electric fuel pump from Amazon. But it absolutely needs to be no more than 4 psi - preferably less. Or if you do use a higher-pressure pump, you'll need to put an external regulator on that you can use to reduce it to 2-4 psi. That's what I did for my 180 gasser with the 2800 when its fuel pump went and I needed to get it going asap.

Although the manual says 5-6 psi, you have to remember that with a mechanical pump the flow decreases as the engine RPM decreases. With an electric pump, it's putting out the same flow/pressure regardless of engine RPM, and you can easily overpower your float with more than 4 psi and cause all sorts of hard-to-diagnose flooding and rich-running issues.

Whatever the case, you want to fix that diaphragm asap, as it will dump a pile of gas into your crankcase if it gets bad.

Noted on the GPH, Doc. Thanks!

DanielW,

I did call them as you suggested and they were very helpful. The nice gentleman was not in love with the AC part number from the service manual as that's "just a number they used", which makes sense.. But isn't that also kind of every model number for everything? He wanted me to confirm it was a Carter M-4220S as the service manual states, but I couldn't find any identifying info on the fuel pump itself other than the AGCO part number presumably as it has a 7 in front of the AC part number. It also has "113" or perhaps "118" below that. These numbers are stamped on a thin metal tag held on by one of the bolts. Other than those, it just says "Made in USA" and "Made in Canada" on two different parts of the body. No other numbers or letters. He didn't like the AC number, but perhaps the AGCO number will be better? I called back but had to leave a voicemail. I'll see how that progresses. I'm assuming it's not a carter pump and was replaced with the AGCO equivalent at some point before I bought it.

Regardless though, thanks for the input! I appreciate the lead.

If you did run it with gas in the case, I wouldn't get too worried just yet. When the one on my 180 went, it dumped at least a gallon or two of fuel in. And it happened overnight: One day I baled with it and checked the oil before baling (like I always do before a day of putting it to hard work). All ok, and worked fine all day. The next day I needed to bring it across the farm to another shed to put the tedder on. Didn't check the oil, because it was only going to be run for a short period (and I'd checked it the day before). Drove North from where it was parked for a few minutes, turned right, and as soon as I turned and the sun was no longer shining/reflecting on the dash, I saw the oil pressure light was on. Goofish mistake by me to not confirm it went out after starting - but the sun shining on it prevented me from noticing it. Shut down, pulled the dipstick out, and found a very thin mixture of oil and gas right up to the top of the dipstick. I thought I'd likely pooched the bottom end or done some other significant damage. But after I drained and refilled (and replaced the pump with an electric one), it's never run better. It starts instantly now, and seems to have more power running the baler. I suspect running that gassy/oily mixture helped clean all the carbon out - just like old-timers who'd run their crankcase full of kerosene for half a minute every few years to clean out their engine. I definitely wouldn't recommend doing it, and if I'd run it under load it would almost certainly have pooched something. But if yours just ran for a little while with only a little gas in the case, I doubt you did any damage. Especially if under minimal load.

If you're not fussed about keeping things original, a low-pressure, 12V pump wired to the keyswitch and a blanking plate on the block where the mechanical pump attaches would get you going just dandy. I don't think you have to worry about GPM concerns: Even the smallest, 2 psi, rinky-dink aftermarket 12V pumps advertised for lawn tractors seem to have at least 26 GPM flow rate. And there are some on Amazon available for $16 with overnight delivery. That would be a cheap/fast way to get you going. I prefer keeping with the mechanical pumps to keep thinks stock./original, but that's primarily because I'm a bit of a nut. Not sure about the XT, but I read later that on the 180's some folks would even just bypass the pump and run the line from the tank directly into the carb with no pump: If you keep the tank at least 1/4 full and have flat land, apparently the fuel level will always be above the carb and flow steadily into it by gravity alone, so you don't even need a pump. Might be worth considering on the XT if the tank looks high enough and you have flatter land.

Noted on the fuel pump design. It made more sense when I was thinking about it last night. Then I felt dumb for not knowing that, lol.

Also good to know on your experience with using far more fuel as a lubricant than I have, ha!

I did make a trip into town today and got the supplies for 3 oil changes total. I changed the oil/filter there in the field and then drove it to the barn without any issues. I also unplugged my drain hole on the fuel pump before that. I'll fix the pump and then give it another oil & filter change in the near future after a bit more running. Then I'll just have the parts for a later change once more.

As far as today goes, the tractor doesn't seem to have any lasting issue, but I realize internal damage isn't always so obvious right off the bat. Perhaps I will discover something it caused another day, but for now I'll take it as a blessing and keep her chugging with a (hopefully rebuilt) fuel pump soon.