Where to Start on Engine Maintenance?

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Reillybrew
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Where to Start on Engine Maintenance?

Post by Reillybrew » Fri Oct 06, 2017 9:28 am

Picked up a M274 A2 last year and have been slow to get it into active duty so to speak. (three kids, other projects, excuses excuses)

Plate Info:
Fed stock No: 2320-074-1167 (??? scratched plate)
Reg No: 337514
SN: BMY 2907
Date of Del: 10/66
Mfr Part no: 8736605
Contract No: DA 20-113-AMC-03624 (?) - last digit couldn't make out really scratched up
MFR model: M274A2
"Inspected" box stamp also has that little stamp with the three stars at the top.

2 cycle AO42, 4 wheel steer. Missing tow bar/tool set, original seat and rails.

Purchased from an auto mechanic. Mule was retrofited at some point with tall removable side walls (attached to current deck holes- no new holes drilled from what i was told), Two beautiful boat seats from walmart, passenger side leg rest cage and seat (the seat is positioned on a welded metal support that attaches to the back side walls which are attached to the frame at original screw points, nothing welded to the deck), electric start, battery box behind driver seat, tow hitch ball attached to engine cage protector. Everything was painted olive drabbish greenish?

I drove it off my trailer and around my yard and after a nice little joyride straight to the garage. Prior to purchase I noticed some leaks around the wheel hubs and drop axles was worried about running the mule with no lube in the joints and causing possibly more damage to the gear boxes. (turns out one was completely empty)

Long story short, it's been in the garage and It hasn't started since, about a year now

Dug into the forum, got info (Chuck W tutorials are a God send- I'm mechanically disinclined but good at following directions), and started digging in to the project. Pulled shrouds and found a mouse nest in the shroud (left side chamber). Completed a lube order as per the manual.

Drained gear oil, trans, bell housing. (waiting on engine work)
Bell housing had small bit of oil drain out.
Transmission appeared to drain what smelled like oil/fuel mix (greenish tint with fuel aroma)- interesting.

Removed Engine oil cap and sniffed, smelled of fuel/oil mix. After reading in the forums I'm lead to believe this may be a leaky Fuel Pump Diaphragm or carburetor issue.

I was told the engine ran rich (sparks plugs would have to be removed routinely and sprayed down to start it up-previous owner).
Signs of excessive oil in Air Filter assembly as well as around air duct tubes en route towards carburetor.(2 tbs in air filter assembly in the base)
The air duct tube itself is banged up and no longer the round tube it was originally. Possibly the reason oil is all over the back end of the engine, due to bad contact between clamp and Air Crossover tube disfiguration.

Purchased boots and seal kits, Carb, fuel pump, Curved air crossover tube from filter to carb intake, air filter, fuel filter. (also steering wheel gear box seal) Also purchased the gear oil, trans oil, engine oil, Marvel Mystery oil, AVgas.
(John Emery parts- thanks for the tips and T shirt!)

Finally finished up replacing all the boots and hub seals on each tire- again Chuck W tutorials are very helpful!(any chance of a carb/fuel pump Tutorial?)

Battery is hooked up to a charger to keep it alive. battery had died previously

Now for the engine work. (I will check the shroud again for any new mouse house as it's been in the garage and have signs of them on the mule itself-actually one fell into the oil pan I have sitting under the mule from draining out the gear oil- WIN!)

I was told to try and get it to start before changing the oil so that the oil will heat up and drain out better. Is this advisable with the level or other possible issues going on or just drain and start on the fuel and carb swap?

I have the manuals printed and digital.

Question: Where do I start and ballpark time on each part replacement?

THANKS for any info!

Pic attached showing mule in it's natural environment - which I hope to get it back to.
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Last edited by Reillybrew on Mon Oct 09, 2017 8:04 am, edited 2 times in total.
M274 A2

muleman7
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Re: Where to Start on Engine Maintenance?

Post by muleman7 » Fri Oct 06, 2017 7:05 pm

The general rule of thumb is drain oil when Hot. But in you case if you have fuel in the oil it will be deluted and I advise to drain the oil cold and raise up the front of the mule to help remove all oil caught in the trap at the drain plug.

If your mule engine has the AC flat top fuel pump I have rebuild kits that will be easier to install with out pulling the bottom housing from the engine.

Image

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Contact me and I will help you with your repairs

E-Mail found in my contact information or phone found on my Web
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Chuck W.
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Re: Where to Start on Engine Maintenance?

Post by Chuck W. » Sat Oct 07, 2017 8:15 am

Nice looking mule! I would do the following: Drain the oil pan and let it sit open for several days so it will drain completely. Change the fuel pump, carb, oil filter, fuel filter and air filter. Refill with 30 wt oil, and add a few ozs. of MMO to the oil. Check spark plugs, should be Autolite 2223, BUT they are no longer in production and hard to find. You can run Autolite 2225 plugs and they are still available. If you have Champion plugs, I would suggest you change to Autolite.

I would also suggest you inspect the gas tank. If it has been sitting for a year with ethanol gas in it, you might want to consider removing the tank, removing the pickup/internal filter assembly and inspecting for rust & corrosion. You can leave the internal filter out with no problems, or there are several different filter ideas on this forum. If your tank has internal corrosion, I have had good luck using RedKote tank liner from O'Reilly Auto Parts, bad luck with POR.

John Emery has reproduction bed rails and seat assemblies, and is doing a lot to provide NOS and reproduction mule parts for the mule community, support him when you can.

Good luck with your project!

Reillybrew
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Re: Where to Start on Engine Maintenance?

Post by Reillybrew » Mon Oct 09, 2017 7:36 am

Thanks Muleman7 and Chuck for the pointers.

Ill post as I get through this.

I do like the look with the standard rails so at some point maybe I'll pick a set of them up. But first things first. Gotta get this one running.

thanks again!
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Re: Where to Start on Engine Maintenance?

Post by Reillybrew » Wed Oct 11, 2017 10:26 pm

So, got blower off, carb off (man that was a pain-that bottom left bolt was slightly stripped, and the heat riser bolts were thoroughly rusted on tight. Upon getting release of that tube I proceeded but noticed the compression fitting may have cracked on that exhaust tube.
Will this be a possible functional engine problem?

After getting carb off, fuel pump off, and oil filter fuel filter I realized my replacement fuel pump is the double hump version vs flat top-
Is the double hump the original pump? and if so I'm assuming it shouldn't be any problem with air tubes or shrouds getting in the way?

Sparks:
picked up a deep socket 7/8" bit a year ago to remove the plugs only to realize that does not reach the mounting bolt and gets bound up by the threaded spark wire tube connection from magneto. Do i need a specialized spark plug puller?
Is there a recommended go to Spark plug socket tool, or does it have to be an aviation spark plug tool?

Drained Oil:
Looked pretty good aside from possible dilutions with fuel (aroma, viscosity was lighter than typical oil)
No Signs of metal shavings, tried to feel around the drain hole for bits, nothing apparent.

Oil filter:
unscrewed and dropped oil filter. Oil looked as the drain pan did with the exception of a nice bit of black goopie slug/black mud near the bottom of the filter. It was drained, wiped out, sprayed down with mineral spirits to break down oil and inverted overnight to wipe down tomorrow.

Fuel Filter and tank:
tank has a shiny interior, few bits of rust noticed near port opening and cap area. Few bits laying on the bottom of tank, dusty in appearance.
Fuel filter near engine looked fine no trapped bits. I will be replacing and will be using avgas 100 octane from local airfield- (does Avgas need Sta-BIL added? assuming no since it has no ethanol)

Mice wised up and went with Fiberglass insulation for their nest this year in the shroud. They've been effectively evicted.

After removing blower fan assembly and shroud to get at carb and fuel pump, while wiping old oil I noticed the 2 horizontal pipes over the right side heat sink/dissipator ( view from rear of vehicle) under the shrouds that shift (maybe 3/8in movement )left and right to a degree. Is that normal? sorry no pic and couldn't find the proper name for them in the manual

Thanks for any insights
Last edited by Reillybrew on Thu Oct 12, 2017 6:53 am, edited 1 time in total.
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muleman7
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Re: Where to Start on Engine Maintenance?

Post by muleman7 » Thu Oct 12, 2017 5:20 am

So, got blower off, carb off (man that was a pain-that bottom left bolt was slightly stripped, and the heat riser bolts were thoroughly rusted on tight. upon getting release of that tube I proceeded but noticed the compression fitting may have cracked on that exhaust tube.
Will this be a possible functional engine problem?

I have this preformed gasket in stock. If it is only cracked then it should be reusable as when it is forced into the tapered seat it will close-up.

After getting carb off, fuel pump off, and oil filter fuel filter i realized my replacement fuel pump is the double hump version vs flat top-
Is the double hump the original pump? and if so I'm assuming it shouldn't be any problem with air tubes or shrouds getting in the way?

The Airtex pump is original for the Powerplant or genset 2AO42 engines not the Mule AO42 engine. In most cases the bottom screw for the air horn tube can not be installed. If you want I have rebuild kits for the original AC flat top 4 screw fuel pump. A lot of mule engines have the Airtex pumps since the rebuild kits only became available within the last year.

Sparks:
picked up a deep socket 7/8" bit a year ago to remove the plugs only to realize that does not reach the mounting bolt and gets bound up by the threaded spark wire tube connection from magneto. do i need a specialized spark plug puller?
Is there a recommended go to Spark plug socket tool, or does it have to be an aviation spark plug tool?


I use a Craftsman 7/8 1/2 drive deep socket. I recently purchased a magnetic deep socket
Aircraft Tool Supply ATS950 Magnetic Spark Plug Socket
from
http://www.skygeek.com/aircraft-tool-su ... ocket.html

Drained Oil:
Looked pretty good aside from possible dilutions with fuel (aroma, viscosity was lighter than typical oil)
No Signs of metal shavings, tried to feel around the drain hole for bits, nothing apparent.

Oil filter:
unscrewed and dropped oil filter. Oil looked as the drain pan did with the exception of a nice bit of black goopie slug/black mud near the bottom of the filter. it was Dained, wiped out, sprayed down with mineral spirits to break down and awaiting inverted overnight to wipe down.

You should have a good engine since your oil was not contaminated by water and residue. the gas contamination should not be a problem. Use a 30wt oil with 8oz of Rislone or Marvel Mystery Oil and change after 2 hours of running with engine fully warm. You can use 2-4oz of the additive with each oil change as it keeps the hydraulic lifters in proper working order.

Fuel Filter and tank:
tank has a shiney interior, few bits of rust noticed near port opening and cap area. few bits laying on the bottom of tank.
filter looked fine no trapped bits. I will be replacing and will be using Avgas 100 octane from local airfield- (does Avgas need Sta-BIL added? assuming no since it has no ethanol)

I use regular pump gas non ethanol with 2oz of Sta-Bil per 5gal. Whether I use it right away or store for a month or so. It helps keep the gas fresh and cleans the fuel system. follow link below for debunk info.

https://www.goldeagle.com/tips-tools/to ... s-debunked

I use Seafoam in the gas tank as a fuel additive. Follow link for a review.

http://www.automotiveforums.com/t940930 ... afoam.html

Mice wised up and went with Fiberglass insulation for their next this year in the shroud. They've been effectively evicted.

Check at least once a year if the mule sits unused.

After removing blower fan assembly and shroud to get at carb and fuel pump, while wiping old oil I noticed the 2 horizontal pipes over the right side heat sink/dissipator ( from rear of vehicle) under the shrouds that shift (maybe 3/8in )left and right to a degree. Is that normal? sorry no pic and couldn't find the proper name for them.

Right side heat sink???????????? the only pipe behind or under the blower is the oil return line from the head to the windage tray or spacer plate. The tubes seen above the cylinder are the push rod tubes and should not move back and forth. They are held in place with either a spring or a plate in the cyl head attached to the rocker arm studs.

Thanks for any insiht
Mules are my passion
www.m274armymules.com

Reillybrew
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Re: Where to Start on Engine Maintenance?

Post by Reillybrew » Sat Nov 04, 2017 8:01 am

Does anyone have a battery recommendation for CCA's?

My current battery is missing some information on the top and dies while cranking over the engine.
Believe it's a Powermaster, (old# 35-60)

It's been hooked up to a charger for awhile and cant hold a charge past one or two 7 second cranks on the engine.

With that being said, do the mules typically crank right over or do they require an extended cranking period to start up?

Thanks
M274 A2

muleman7
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Re: Where to Start on Engine Maintenance?

Post by muleman7 » Sat Nov 04, 2017 3:12 pm

Replace your battery you are only cranking a 14hp engine a good battery should hold up to many cranking sessions before charging.

I designed a Battery Box that can mount the battery side out or face out. It does not hang below the Frame Tubes. I have them in stock or can provide cut list and assembly instructions. E-Mail me with questions or order information.

I use a Group 75 Battery 690 CCA 820 CA @ 32 degrees F from Orally Auto Parts. I make up my own 4 gauge welding wire leads. No problems with cranking and running aux accessories including 2.5K or 3.5K winches using 6 gauge wires.

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The Battery Box is supported with either 2 or 3 under bed supports not requiring drilling holes in the top of the bed. Universal fit for either Aluminum or Magnesium beds.

Image

Side Out Allowing the Foot Basket to be stowed under the bed using original spring clips.

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Face Out does not allow the Foot Basket to be stowed under the bed using original spring clips.

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Mules are my passion
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Reillybrew
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Re: Where to Start on Engine Maintenance?

Post by Reillybrew » Sat Nov 25, 2017 8:16 am

OK, new battery purchased along with battery maintainer, worked well cranking over and started a few times until i began to notice Fuel dripping from muffler... Really stumped on this.
Mufflerfuel3.jpg
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Re: Where to Start on Engine Maintenance?

Post by Grummanflyer » Sat Nov 25, 2017 8:39 am

Did you have it flooded when you were trying to start it? It's obviously unburned fuel so you either have a bad plug, low or no compression, etc. There are alot of things that "could " be wrong here. Start by pulling both spark plugs and making sure they are both firing. You should also check the compression on both cylinders. Does it even try to keep running? It's possible that is residual left over from many starting attempts but it should go away really quick after you get it started although it would not be uncommon for it to run crappy for a little bit until the engine has a chance to clean it's self up.

John
When I read about the evils of drinkin, I quit reading.

Reillybrew
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Re: Where to Start on Engine Maintenance?

Post by Reillybrew » Sat Nov 25, 2017 9:15 am

thanks John,

Definitely doesnt fire on the first go around typically, so I'm probably flooding it. When it does start it runs seemingly well with no issues or lagging or power loss. Sparks are new Autolite 2223 gapped correctly.
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Re: Where to Start on Engine Maintenance?

Post by abbylind » Sat Nov 25, 2017 10:35 am

Check the couplings on your fuel lines. Might be dripping down to the muffler area....
Remember the word "expert".....An "EX" is a has been.... and a "SPERT" is a little drip...

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