My slightly nicer but also terrible Bobcat (742B)

[Scott Cee AKA 2drx4]

This was one of those deals that was so good I was practically going to lose money if I didn't do it.

The guy I got it from bought it sight unseen, was told it "smoked a bit" but worked fine, and paid for it to be delivered. Turns out it smokes so much it could be mistaken for a Subaru owner hitting a vape pen. He got upset about the deal and parked it in his shop for a year or two, then sold his house and had to get rid of it because he wasn't going to have space. He fired it up before I went to look at it, you know the old "get it warm so it runs nice" before the guy comes to look at it. When I got there he was very flustered, as it had died and absolutely refused to start again. I looked it over, thought about it, and told him I'd get back to him.

Not knowing that these things will not fucking move if they aren't running and you don't have the tool to release the hydraulics, I made him a low ball offer and returned with my trailer/winch. I dragged my whole truck and trailer into the thing trying to get it on, and once it hit the ramps it was clear it wasn't going to happen. Ah, so no choice, have to get it running to get it on the trailer. It had spark, and chugged enough to imply compression, so I pulled the fuel line off to the fuel pump and a bit of fuel dribbled out and that was it. We checked the tank with a stick and it was full. I had read about them having a fuel shutoff solenoid that fails, and assumed it was that (it wasn't). He had some hose and a bottle, so I ziptied it to the engine and got enough gas in it so it would run to get on the trailer.

Easy peasy, right? Well, the fucking thing broke the timing belt when I went to get it back off my trailer. The best I can tell the head sheared off one of the tensioner bolts and got sucked into the cog and broke the belt. But I am speculating. There was a sheared bolt and a stray bolt head in the timing case.

Luckily it came with a spare timing belt (the belt might have been chewed before this, who knows), so I put a new belt on. Note, the information on the internet about the timing marks on these things is wrong, I may explain later. It fired right back up after I timed it correctly. I promptly ran it out of a fuel before getting to my shop, and pinned myself in because I had the bucket up. I did remember that there's a knob to pull to release the loader hydraulics before I pushed out the back window, so I at least saved myself that extra trouble.

[Scott Cee AKA 2drx4]

This thing came with about 12 tires. I think he put the solids on the front while he was getting a new one put on one of the rims. I will swap back to normal tires at some point. And it did come with a bucket, I dropped it behind the shop to save space. It came with chains too.

I did want to figure out why it wasn't getting fuel, filling a pop bottle up to run it wasn't very handy. The gas tank on these things is between the cab and engine bay, so to get at them you just flip the cab up.

I believe it's missing a safety strut to hold the cab up if the stupid gas struts fail, so I ratchet strapped it on the back. Not sure if this is legit, but it seemed to work.

Somebody pinched the fuel hose behind the tank at some point. There's an indent in the tank where it's supposed to run, they got it out of that so it got squished. The tanks (fuel and hydro) are supposed to be secured with a strap I believe, it is missing, but the bolts are there. Nifty. I put some new hose in taped it so it stays where it should, and after priming the fuel system by sucking the air out with a big syringe, it fired right up. Good.

The bad news was after some simple diagnosis, I determined the massive oil burning/smoke wasn't likely anything stupid and easy. So, time to take the engine out.

[Scott Cee AKA 2drx4]

View of the main pump with the cab up, for anyone that hasn't seen this garbage before:

This is about where I got to tonight. Governor off, alternator off, timing mostly apart (again), bunch of other stuff is loose.

I've got a ton of things going on but I need to get this thing out and apart ASAP. So hopefully I can hit it over the next few nights.

The engine is a Mitsubishi 4G32 and they have a reputation for being pretty crap. Also the parts for them seem sketchy. So hopefully this doesn't turn into a total disaster.

[Scott Cee AKA 2drx4]

Also, if it's not apparent, I really don't know much about these things. I never ran them much at work, and certainly never had to work on them.

[Scott Cee AKA 2drx4]

I poked at it a bit more before going to work this morning. I stripped most of the accessories off the engine, which I don't believe I have to do in the machine, but my stands are full of garbage so this is just as easy.

I think cylinder #3 will be what my issues are.

I'm also curious if the intake manifold actually sealed. Looks like the RTV'd it.

You are supposed to RTV around the water passage (thermostat is in the intake manifold), but I think they didn't use a gasket at all. I'll find out when I get it off.

Somebody has had a bunch of this stuff apart and made no effort to put things back together correctly. The muffler and radiator were not attached to anything, and the big fan shroud is definitely just kinda in there. Lots of dumb stuff to fix.

I like how somebody tried to weld up the rotten muffler.

[Scott Cee AKA 2drx4]

Question. How do people feel about running without a timing belt cover? The upper cover was not included with the machine, the lower cover is bent and damaged from rubbing on the belt/pulleys, both are NLA from Bobcat. The chances of finding a Dodge Colt to steal one from seems low, and the Mitsubishi cars that use this engine (4G32) were basically not sold in Canada. Is it really needed, or just there to keep fingers attached to hands?

Edit, it does have the ignition timing marks on it, but I think it doesn't matter because I have a digital dial back light, so I just need the TDC mark and the pointer, there is a pointer inside the timing case for TDC so it would just require marking the pulley. See my vague comments about how the information on the internet is wrong about timing these, there is a set of marks there that indicate TDC and you do not use the outer marks for installing the timing belt.

[Scott Cee AKA 2drx4]

I got the engine out, and the oil is obviously from a destroyed valve guide. The bores are a bit beat up so I will opt for a full rebuild because it seems like it's worth it.

Yanking it out, it's an awkward thing.

The big squirrel cage fan melted at some point, I guess they got this engine (or the one before) right hot. The radiator has been repaired, and no thermostat in it, so ehhh.

Broken bolt on the fan, which is what attaches it and the driveshaft to the flywheel. That's a good sign.

What's the thoughts on the exhaust valves? Running lean and burning some oil on them? The intake manifold was not likely sealed on at all, so lean is plausible, and there was oil being put in from the CCV.

[Scott Cee AKA 2drx4]

Engine is out, apart, and dropped off at the machine shop. Hoping it doesn't hurt too bad.

It does use a neat little gerotor oil pump. There is some wear on the faces of the aluminum housing, but the gerotor itself is in very nice shape. Is it worth it to try to lap the housing? Or just slam it back together when the time comes? I do not believe any of these parts are available.

Pickup was well on its way to clogging and total destruction.

The long block is small and light enough that I carried it out to my TJ by myself. That said, I won't do that again, it wasn't light enough that it was comfortable.

Anywho, this is probably going to just marinate for at least a few weeks while waiting for machining and then parts. Maybe longer. I need to clean up all the accessories and fix a bunch of other crap in the meantime though. And clean the shop, man was everything on this nasty.

[Scott Cee AKA 2drx4]

There was a broken off bolt for the timing belt tensioner in the cover. I thought this might turn into a gong show but I managed to just turn it out with an automatic centerpunch on a 45 degree angle.

Small victory.

[arse_sidewards]

I wouldn't lose sleep over no timing cover. I've got probably 100k with no timing cover no issues among my Subarus.

Unless you're gonna toss the keys to some knuckle dragging "operator" and have them doing forestry shit flinging garbage all over and getting the whole machine packed full of stuff it will probably be fine.

[Scott Cee AKA 2drx4]

Inside of the oil pan:

The paint is flaking off in places. I'm guessing I should probably strip/blast it all off? That might have been part of what was plugging the oil pickup.

Coil question:

The Bobcat P/N for this is NLA. Is there really much different between coils as long as you get one that's marked for (or not) an external resistor and the voltage? I ordered one that is listed for the car that has this engine and uses an external resistor. I just want it for a spare, I plan to put the old one back in as the engine was running so I'm sure it's okay.

https://www.rockauto.com/en/moreinfo.ph ... 60&jsn=962 Is the one I ordered.

[Scott Cee AKA 2drx4]

I took off the 2 solid tires and sold all 6 solid tires I have. I can't see needing them, and they weigh 250lbs each or something and are super miserable to do anything with. Then I realized one of the air tires that it came with installed was on backwards.

They're pressed center, not reversible.

On the right way:

There's lots of just odd stuff that was done with this thing.

[Scott Cee AKA 2drx4]

Carbertooter time:

This was after I hosed it off with two cans of brake cleaner. It's some Mikuni thing, I guess if you're into the import scene you might be familiar with them. They are NLA from Bobcat, but I think you could get on that would work if you had to.

It's a 2 barrel, but it's not. They put a blockoff plate in the secondary, and there is no jet in that side. There is a tiny hole (that was plugged) in the blockoff plate, not sure exactly what for but eh.

After a bunch of time in the ultrasonic cleaner:

Rebuild kit I got:

This kit is for the Dodge Colt, I believe, and it is not right. It has most of the parts but not all. More on that later.

Accelerator pump is corroded pretty bad:

The checkvalve for the accelerator pump was also seized, but there's no way to get it out without drilling out plugs. I flushed it a bunch and it seemed like it was moving a bit at least, so I'm going to run with it for now. I don't know how much it matters. Clearly it was doing nothing for a long time and the machine worked pretty decently despite everything that was wrong. You can see there's a fair amount of corrosion from using shitty ethanol gas in this thing, it's like come onnnn, you're legally allowed to use the purple fuel so why not.

Cleaned up and back together:

(Some hardware is missing)

[Scott Cee AKA 2drx4]

So, as to the Walker 15881B carb kit that was alleged to fit, it is mostly right but not totally. One problem I've had with this machine is there is a lot of myth and not a lot of fact in regards to the Mitsubishi 4G32 engine.

One big difference is the float needle and seat:

I just reused the old one, it was still okay. There is a chance there is a different kit that has the right needle and seat, but I'm not bothering unless it's a problem. Realistically if this carb gives me issues I will probably look for a replacement, even if it means I have to put an actual 2 barrel one on.

The other thing is didn't have, and I forgot to take a picture of, is there is a bimetallic strip temperature compensator on the one side, and the gasket for it is a bit odd, and definitely not included in this kit. I debated cutting a new one out, but I think I'll just try it for now, it's easy to get at if it proves to be some sort of issue. I doubt it will be.

Another thing I have to fix is that somebody mangled the threaded hole for the bolt/stud that holds the hat on:

I think I'll try to find a stud and epoxy it in.

[Scott Cee AKA 2drx4]

This is more because I plan to eventually make a long (and annoyed) post on the actual skidsteer forums about the entire Mitsubishi 4G32 engine topic, and in case some random Googler comes here looking for answers. Guys claim that the engine that came in the Dodge Colt is the same, and they are right, it is a Mitsubishi 4G32, BUT it is quite different because it has a counterbalance shaft and a bunch of other changes. I don't know how many changes. If you ask about these engines on any of the skidsteer forums you will simply be told to buy parts for a Dodge Colt. They are not the same, although some parts may be workable, there is way more to the story than "just buy Dodge Colt parts."

Waterpump for example:

The crusty old one is the genuine Bobcat part, which if you want a replacement for is now some $600. The new one is a Dodge Colt part, which is probably old stock only at this point, but I paid $28 for it.

It is different in overall height, the flange diameter and bolt pattern for the pulley, the outlet is longer and meant to take some odd hose adapter piece, and the actual mounting pattern and shape is a bit different. I believe if you needed to use this you could machine up a spacer/adapter for the pulley, cut the outlet off and thread it for a hose barb or nipple, cut the extra casting off, and make it work. There may be some ramifications on how it fits with your timing covers, assuming you have them, but otherwise it appears it could be made to function as the genuine Bobcat part. However, if you were planning to "just buy Dodge Colt parts" and bolt the thing on, you would not be so happy. I will keep it for use later if I need to, but this is setting the record straight on the parts not being the same.