Running Rich

I have a 1960’s International Harvester 3414 Backhoe / Loader with a BD154, 4 cylinder gas engine.

It has been used heavily over the years and has a number of things wrong with it, but remarkably, still does the job.  It would take a week just to find an fix the numerous hydraulic fluid leaks.  Gauging from the locations of the puddles on the ground after using it, I have a leak on the loader arm, power steering ram, backhoe connections, and one from the tank itself.  They all have varying amounts of fluid loss, which is somewhat based on the part of the backhoe I’m using the hardest.  Sadly, it’s cheaper to just keep buying hydraulic fluid than it would be to track down and fix the leaks.  It is “on the list”.

The engine does run, although it’s been years since I heard all the cylinders running at the same time. 

Usually two are going together and a third will chime in every now and then, and the fourth one, just gave up a while ago.  It doesn’t burn oil, or smoke too awful, which is great.  Usually when it starts running really rough on two cylinders I:

• Shut it off and wait for it to cool down
• Take all the plugs out and clean them off
• Spray a little carb cleaner on them
• Brush them with a wire brush
• Blow them out with compressed air and
• Put them back in

It runs like the bees knees for about 5 minutes and then starts to die out again.

I’m pretty sure that it’s running rich all the time.

I put a fuel shut off on it to fix a problem I had with it last year.  (link here)  As a result, everytime I’m done using it I shut the fuel off and wait for it to run out.  However, just before all the fuel as been run out of the system it perks up and runs like a top, just as smooth as slik, then dies due to lack of fuel.  I’ve played with the idle screw, but that only effects how it runs at idle.  The air screw seems to have no affect either and so I just turned it in all the way and then backed it out 1 and 1/2 turns and then played with it until it sounded “the least terrible”. I hesitate to say sounded great, or even good, so I’ll say, less bad.

For years I suspected this backhoe needing a full engine overhaul due to it fouling plugs so often, assuming there was oil blowing by the rings and fouling the plugs.  I mentally and financially prepared for the worst and called around to some tractor places.  $2000 for labor, $1000 parts.  Woah… for a tired leaky tractor that was a lot of money.

I shelved that idea and decided to just run it like it was.

This year I intend to build a garage. (see link)   In order to build said garage, I need to clear the spot where it will go and get down to ledge.  It’s only a foot or two below the surface of the soil, so pouring footings isn’t really an option.  I will basically build forms that contour the ledge, and drill and epoxy “good sized” rebar into said holes and that should keep the garage from falling off the planet in case we somehow lose all gravity on earth instantaneously.  So i’ve been scraping away with the backhoe, and pushing down trees and roughing in a road.  It’s been running rough, but respectably holding it’s own and not giving me any problems what so ever.

I called my Dad as I often do with problems relating to engines, especially engines which he’s worked on before. (he gave me the backhoe!)  He said, it’s pretty much always been like that, and that he even bought a new carb for it and it still had that problem, and he couldn’t solve it.  Now I seem to remember this backhoe running much better than this when I was a kid.  And this carb looks far from new.  I think sometimes my Dad can think about doing something so much, that he thinks he did.  Or perhaps he did, and this carb just looks older than dirt and or was used when he bought it.  Either way, that led me to the conclusion that regardless of the family history of this carb, it must either be the wrong carb for the engine, or it is and was out of adjustment.

So I went on a search across the internet looking for the proper carb for my backhoe and more specifically this engine.  I came across a page that stated the BD144 engine should have a zenith 30VNN carb.  The BD154 was listed but it had no information under the carb section.  Now I’m not entirely sure if mine is a BD154 or a BD144, however that number relates to the Cubic Inches of displacement, i.e. 154 CI.  Either way, with the information about the carb 30VNN, I went on a hunt for pictures of such a carb to compare to my carb, the result of which were negative.

My carb was not a Zenith 30VNN.

This leads me to believe I have a BD154 being that they didn’t match, and that the BD154 did not have a listing for 30VNN.  I did a search on the same website with the picture of the 30VNN for “harvester” noting that it listed it under International Harvester, and it returned one other Carb a Zenith 30VNP.  Ah ha, I thought, perhaps the BD154 has the 30VNP instead.  Well, it very well may have that carb, however it wasn’t the same as mine either.  Strange.

I need to find out what I had for a carb.

Clearly it wasn’t either of these, but it was a zenith because it was cast on the side.  So I went to ebay and did a search for “IH 3414”.  meh.  Some results, lots of manuals, which I will admit would probably be a quick way to find information.  Buy a manual wait for it to come in and look it up.  But, I want it now! So I did a search for BD154 in the agriculture and farm category. Lots of cylinder heads and crankshafts, short blocks, people parting out machines.  I went to one item that was clearly a “part out”.  (this is where someone has a machine in some state of running or not running and decides to take it apart piece bye piece and sell it on ebay)  Once at the item, I think clicked on a link that takes me to their “store” or “sellers other items”.  The logic here is to find all the other parts off this same machine, hoping for the carb.  No such luck, it was probably already sold.  So back to my BD154 search and I found a carb that looked just like mine, that was brand new. $499 bucks I might add.  So there it is.

Fits International: B414, 3414, 3444, 354, 7000 FORKLIFT W/ BC-144 GAS ENGINES, 2300 SERIES A Other Info: NEED A CARB GASKET? USE ABC416. Dimensions & Notes: LOOKS DIFFERENT, WORKS GREAT — DOWN DRAFT Carb MFG: 3063945R91, 3044193R92 Replacement: IH: 3063945R91, 3044193R92
IHS377

It’s a zenith model 33 manual choke.  Ok, so then I can be assured that somewhere along the line the original was canned and this replacement was purchased (most likely by my father, who due to an internet search has been redeemed!, so he’s not crazy, 1 check mark under not crazy).

So now what?  Well, now I know this.  This carb was made to replace the original.  So it is “suppose” to work.  This means it MUST be out of adjustment.  What to adjust?  Well I know none of the specs, jets, needle sizes, throat size, air screw, idle screw.  So after a quick and seemingly unhelpful conversation with a local tractor repair shop, I decide to adjust the floats.  The guy behind the counter, who looked like he’d just crawled out of a can of grease where he was napping, said “could be floats, but won’t know till you bring it in….“.  So I did a google search on just ”running rich adjust floats“ and found a number of people who had success by adjusting the floats so that it cut the fuel off sooner.  So…

I took the carb off.

This sentence is so short because it really doesn’t need any other explaination.  It’s the choke cable, fuel line, governor rod and two 1/2 inch nuts.  Pop off the intake boot, and you’ve got a carb in your hands.  So I brought it up to my workshop.  Which at the moment was a bucket parked half under the eave of a roof.  Four screws and a gentle pry and the carb was bleeding in my hands, like a live heart, except not live, or soft.  The floats looked like they were hand braised in 1929 in the middle of sandstorm, and then carried by horseback through a desert then on a cargo ship in the front pocket of someones cover-alls, and installed in this carb.  They were dented and bruised, honestly it looked like they rattled around in a toolbox mounted to a plow truck.  Ok, enough mental pictures.

I took the floats out and bent them.

Then put them back.  Pretty simple really.  I bent the tab that rests on the needle valve ever so slightly so that they engage sooner as the fuel rises.  I reassembled and put my mouth on the fuel inlet and blew, at the same time rocking the carb back and forth to listen for the floats opening and closing the needle valve, which they did.  I shrugged at how simple this whole affair was and reassembled the carb.  ”Reassembled the carb“, it’s almost unfair to say it that way…. it was four screws.  I set it in my toolbox to install later, as it began to rain.

Well little did I know that in the middle of the night 4 jolly, iridescent elves snatched the carb and….

The next day I installed the carb.  2 nuts, governor rod, choke cable, fuel line, air inlet boot.  Turn the fuel shut off to on (which dare I admit is actually a 3/8” pex water ball valve!).  Put the battery cable back on, put it in neutral, pulled the choke, and cranked it over.

It ran.

That’s always the first thought after I “fix” something.  Notice that “fix” is in “quotes”.  The first feeling is, holy crap, it still works.  I haven’t begun to classify the manner in which it works, just that it in fact doesn’t NOT work.  Excellent.  Next was…well…will it flood out and run rich.  Apparently not.  For the next few minutes it ran pretty strong on what sounded like all cylinders.  So…

Success!

However, I’d like to see it run a little better.  Seems maybe it could run smoother but I haven’t really gotten a chance to stretch it’s legs.  I”ll post a follow-up when I do.

Short Version:

Hey if your tractor is running rich all the time, you could try adjusting the floats down in the bowl.