Looking at buying a 742B. Tips on what to look for?

[2drx4]

Disclaimer: I'm not much of an experienced equipment guy, but I fix aircraft for a living. I'm planning to look at a 742B in a few days, and I want to know what to look for or what to inspect. I plan to use it for plowing my driveway and some very light landscaping work for the time being. I know these machines are not really considered to be good for much more than the home jobber now, and that's basically what I am.

It allegedly has 3900hrs on it and the Mitsubishi engines is consuming oil significantly. I will try to determine how bad when I look at it, but reading suggests that these engines tend to wear out and do this. I am not afraid to rebuild it as long as parts are available.

As to the rest of it, what is a non-starter? I know to look for cracks in the loader and chassis (looking for cracks is literally half of what I do for a living), but I'm not sure if there is any known problematic areas. Worn pins are normally easy enough to spot too. What about wear in the wheel/drive assembly?

As far as a test goes, make sure it doesn't buck when going straight? No creeping when you have the sticks in neutral? Obviously check the loader goes up and down and curls, and does it smoothly. No leaks or drips too, obviously. I'll pick his brain on service history, see if the oil in the governor has ever been changed, but from the pics I can see it has clean new filters on it. What else?

Thanks for any advice.

 

[brdgbldr]

Disclaimer: I'm not much of an experienced equipment guy, but I fix aircraft for a living. I'm planning to look at a 742B in a few days, and I want to know what to look for or what to inspect. I plan to use it for plowing my driveway and some very light landscaping work for the time being. I know these machines are not really considered to be good for much more than the home jobber now, and that's basically what I am.

It allegedly has 3900hrs on it and the Mitsubishi engines is consuming oil significantly. I will try to determine how bad when I look at it, but reading suggests that these engines tend to wear out and do this. I am not afraid to rebuild it as long as parts are available.

As to the rest of it, what is a non-starter? I know to look for cracks in the loader and chassis (looking for cracks is literally half of what I do for a living), but I'm not sure if there is any known problematic areas. Worn pins are normally easy enough to spot too. What about wear in the wheel/drive assembly?

As far as a test goes, make sure it doesn't buck when going straight? No creeping when you have the sticks in neutral? Obviously check the loader goes up and down and curls, and does it smoothly. No leaks or drips too, obviously. I'll pick his brain on service history, see if the oil in the governor has ever been changed, but from the pics I can see it has clean new filters on it. What else?

Thanks for any advice.

I had a couple of 742's. The one I kept the longest had the two piece axels. Much easier to replace the axels seals on a two piece. Look for a large bolt at the end of the axel, if it doesn't have one it is not a two piece axel. There were two versions of the 742B with the Mitsubishi 4G32 engines. The later ones have the two piece axels.

There are several post on the forum of people trying to find rebuild kits for the engine. They do not seem to make them anymore. However, people have managed to find all the parts needed to rebuild them. A good engine rebuilder / machinist can rebuild anything as long as it is not cracked.

The Mikuni-Solex carburetors are no longer available. There are other carbs that can be used.

The fuel pumps are hard to find, if at all, but an electric fuel pump can be installed as long as it is the correct pressure.

The governors are just about impossible to find so do make sure the one in the machine has been maintained. The linkages wear out but you can still get those new from Bobcat.

Make sure the auxiliaries work. The right lever should move from left to right to operate them. If you go all the way to the right a detent should engage that keeps the auxiliary on. Move to the left to disengage it. If the right lever does not move side to side it could mean that the auxiliaries were locked with a bolt on the lever so they could not be used. Or it could mean that they don't work.

Make sure the "float" works. Press the left pedal at the tow all the way down and a detent should hold it. This causes the lift arms to "float". With the pedal in detent, curl the bucket down and the arms should raise, not the front tires. Press the heal of the pedal to disengage the "float".

On any machine, you should be able to pull up to an immovable object, like a large tree or bolder, and press both levers fully forward and have the tires spin or at least the engine should not cut out.

Take a look at the oil cooler and radiator to make sure it has been cleaned of debris. If it is plugged up the machine may overheat and it will also hide any leaks.

Smell the dipstick. If it smells like gasoline the carburetor will need to be rebuilt or replaced.

You should try to get the seller to lift the cab for you. A lot of older machines are so clogged up with dirt and debris that the leaking oil can't get out. So don't think that just looking underneath for oil will tell you if there is a leak or not.

You can pull back and forth the on the tires to see if there is any axel play.

Make sure the quick-tach levers work. it is not fun trying to get them unfrozen.

That's about all I can think of unless you can get a compression test.

Good luck

 

[2drx4]

I had a couple of 742's. The one I kept the longest had the two piece axels. Much easier to replace the axels seals on a two piece. Look for a large bolt at the end of the axel, if it doesn't have one it is not a two piece axel. There were two versions of the 742B with the Mitsubishi 4G32 engines. The later ones have the two piece axels.

There are several post on the forum of people trying to find rebuild kits for the engine. They do not seem to make them anymore. However, people have managed to find all the parts needed to rebuild them. A good engine rebuilder / machinist can rebuild anything as long as it is not cracked.

The Mikuni-Solex carburetors are no longer available. There are other carbs that can be used.

The fuel pumps are hard to find, if at all, but an electric fuel pump can be installed as long as it is the correct pressure.

The governors are just about impossible to find so do make sure the one in the machine has been maintained. The linkages wear out but you can still get those new from Bobcat.

Make sure the auxiliaries work. The right lever should move from left to right to operate them. If you go all the way to the right a detent should engage that keeps the auxiliary on. Move to the left to disengage it. If the right lever does not move side to side it could mean that the auxiliaries were locked with a bolt on the lever so they could not be used. Or it could mean that they don't work.

Make sure the "float" works. Press the left pedal at the tow all the way down and a detent should hold it. This causes the lift arms to "float". With the pedal in detent, curl the bucket down and the arms should raise, not the front tires. Press the heal of the pedal to disengage the "float".

On any machine, you should be able to pull up to an immovable object, like a large tree or bolder, and press both levers fully forward and have the tires spin or at least the engine should not cut out.

Take a look at the oil cooler and radiator to make sure it has been cleaned of debris. If it is plugged up the machine may overheat and it will also hide any leaks.

Smell the dipstick. If it smells like gasoline the carburetor will need to be rebuilt or replaced.

You should try to get the seller to lift the cab for you. A lot of older machines are so clogged up with dirt and debris that the leaking oil can't get out. So don't think that just looking underneath for oil will tell you if there is a leak or not.

You can pull back and forth the on the tires to see if there is any axel play.

Make sure the quick-tach levers work. it is not fun trying to get them unfrozen.

That's about all I can think of unless you can get a compression test.

Good luck

Wow, thanks for the informative reply.

It is the later style with the 2 piece axles, so it has that going for it.

I've been reading lots about the engine rebuild scenario. There is lots of super sketchy rebuild kits available, but some (or most) of them seem to have the wrong parts. That is a concern, I'm in Canada so it's harder to get parts (vendors won't always ship here) and they tend to cost more due to high shipping costs and be impossible to return. I will have to talk to the local engine rebuilder to see what they have to say. It looks like it's easy enough to source some parts through Rockauto and they're cheap enough to gamble on, as long as you don't need to go to oversized pistons, if you need them it looks like it's a rabbit hole at that point. Also a lot of the kits seem to list as having cylinder sleeves, I wouldn't have thought this engine used sleeves from the factory so there likely is some shenanigans going on there. It would be tempting to do a compression check and throw my borescope into the cylinders before buying, but I don't know how much patience the seller will have for that. I'll have to look into carb rebuild kits too, but I can always get it to work with something else, like you said.

Good to know how the auxiliary works and the float. I didn't know anything about the auxiliary and planned to just ask the seller. Float makes sense, works the same as my mini tractor.

The main hydraulic pump was recently replaced, I plan to ask more about that, but I'd like to think they cleaned everything up when they did that. The engine compartment area does look clean by equipment standards. How hard is it to lift the cab on these?

He's had the bucket on and off (has photos of it both ways and I asked to make sure its included) so I'm guessing the quick-attach stuff isn't seized.

Thanks again for all the pointers.

 

[brdgbldr]

Lifting the cab is easy as long as the struts still work. All you have to do is remove two 3/4" bolts located in the front two corners of the cab. Then just lift the cab all the way and make sure the cab locks in the up position. To lower the cab you have to press a bar that is located on the strut on the right side of the machine (left side of looking from the front).

If the struts are no good the cab is extremely heavy and hard to lift.

Just a note when lowering the cab. The throttle lever needs to be at about halfway otherwise the cab will most likely hit it.

 

[2drx4]

Just a note when lowering the cab. The throttle lever needs to be at about halfway otherwise the cab will most likely hit it.

Thanks again for the info. I'll ask him if he's had it up recently and take some tools when I go.

 

[JakeK]

If you want a quality engine kit at a reasonable price I would recommend Cleggs Engine. https://www.cleggengine.com/. If you can't find it on the site call them. All my hard to find engine kits they've either had it stock or were able to locate the parts.

 

[Dave1234]

I recently bought a 742B at a distance so unseen, but from a farm dealer. Described as "in excellent condition" which for a 30+ year old machine it is. That said, don't expect no oil leaks. That seems like an impossible request in my experience. Probably drive an aircraft mechanic nuts trying to eliminate them to aircraft standards. Essentially all my hyd hoses are OEM, dated 1994, hard as rocks. Expect to replace many as you work on things. As to rebuild kits with sleeves, be sure they aren't for the diesel version, which do take sleeves. They could be mis-labled, although boring and dry sleeving a gasoline engine is definitely doable. And for compression tests, from other posts here, it looks like these engines were installed with the dished pistons otherwise used on the low compression turbo engine in automobiles, meaning you can't do a wet compression test, unfortunately. That might be a good enough excuse to get an ok to use a borescope. FYI, my engine has 2200hrs, seems to be in pretty good shape, and appears it should have a proper compression of 150 psi. It appears that Bobcat and Mitsubishi worked hard to derate the HP of this engine--low compression pistons, 1 blocked carb venturi, cam--I don't know. Mine appears to be pulling a lot of oil past the valve guides on cylinders 1 and 2, while 3&4 have lower compression but clean plugs. I suspect/hope the intake stem seals are installed crooked or failing. There is a special tool for installing then that no one is likely to have. On my machine, lifting the cab is doable but heavy. I don't know if there is an air lift cylinder and a spring, of just a spring with an air cylinder to slow it down in lowering it. As I do repairs on my engine, I try to find which automotive parts fit, and post details here. I am trying a product called Flairtite seals, which are coated stainless steel caps to go inside the JIC hyd fittings to eliminate leaks. Not cheap--$3-6 each, but cheaper than a new hose. If you are picky about leaks/seeps where they shouldn't be and don't want to be running to the hyd store every time you open an old/leaky fitting, they appear good to have on hand. And Float on mine-- I still need to investigate further, but at this point I will say that just pushing the pedal tip all the way down doesn't allow it to latch in detent for float. I have to slam it down fast to get it to catch in the detent position. I assume there is either wear on pivot points, or an adjustment, but just be aware that it may be hard to get it into detent/float. I don't know if just holding it down will be adequate to test it yet. I'd be interested to hear what you find, or anyone elses's feedback to postings here.

 

[2drx4]

Mine appears to be pulling a lot of oil past the valve guides on cylinders 1 and 2, while 3&4 have lower compression but clean plugs. I suspect/hope the intake stem seals are installed crooked or failing. There is a special tool for installing then that no one is likely to have.

I've found references to Mitsubishi engines in general having issues with leaking guide seals. I wonder if a competent engine machine shop can just drive in and ream a universal guide that takes a modern seal instead of whatever contraption Mitsubishi came up with? It is done often on some older engines.

If I was super lucky, and I certainly am not, this engine might just need valve guide seals, a quick dingleball hone on the cylinders, and some fresh rings.

As to those repair seals (Flaretite), there's an aviation standard part that's basically the same thing, I'd have to look in my notes to find what the P/N are (not that anyone cares). They work okay, more something we'd use if the one part was not able to be procured or replacing it wasn't possible at that time. If you do get it together with them and it doesn't leak, I recommend never touching it again until you have new parts.

Thanks for the info though! Still pretty torn on what to think about this, I'm thinking the seller looked into what a cluster it is to find parts and info to rebuild the engine and that has resulted in his decision to sell it for what he has it listed for (way less than any other modern skidsteer listed, and actually less than a beat up old 610 even).

 

[Dave J]

Make sure when you lift the cab to try to grease the universal and slide between the engine and the hydraulic pump. If it has been done it will take grease easy. If not, it will be hard to get it to accept grease and very difficult to remove the engine. As the owner to show you how to grease it. If he does not know it may have never been done. Very expensive part and hard to fix. Don't ask how I know.

 

[Dave1234]

Mine also leaked engine oil prodigiously from the front of the valve cover, and base of the fuel pump. The valve cover won't seal without RTV on both sides where it goes over the cam housing. The fuel pump had a stray piece of old gasket + RTV which didn't work. Expect lots of nuisance type things to get its oil loss down.

 

[2drx4]

Make sure when you lift the cab to try to grease the universal and slide between the engine and the hydraulic pump. If it has been done it will take grease easy. If not, it will be hard to get it to accept grease and very difficult to remove the engine. As the owner to show you how to grease it. If he does not know it may have never been done. Very expensive part and hard to fix. Don't ask how I know.

I was reading about that, and the parts don't seem to be available from Bobcat. They had the pump off for rebuild (or replacement, I need to clarify), so hopefully he hasn't just started greasing it after the found it chowdered when they did that. I will ask one way or another.

 

[2drx4]

Mine also leaked engine oil prodigiously from the front of the valve cover, and base of the fuel pump. The valve cover won't seal without RTV on both sides where it goes over the cam housing. The fuel pump had a stray piece of old gasket + RTV which didn't work. Expect lots of nuisance type things to get its oil loss down.

There's definitely oil leaking out of it too, so I am wondering how much is consumption versus loss.

Did you buy new gaskets for everything from somewhere, or just got at it with the RTV?

 

[Dave1234]

I cut my own fuel pump gasket, used RTV on the existing valve cover gasket as a temporary fix pending a valve adjust and possible stem seal replacement. FYI, I try to avoid RTV as much as possible, but in this case the mfg says you have to on both sides of the front cam bearing. Its very hard to get RTV to really stick, and if you do it takes dynamite to get things apart. I bought automobile gaskets for the valve cover but haven't used them yet. In a car, I recall that 1 drip per mile = 1 qt/500 miles. leaks add up fast.

 

[Chris 8603]

Wow, thanks for the informative reply.

It is the later style with the 2 piece axles, so it has that going for it.

I've been reading lots about the engine rebuild scenario. There is lots of super sketchy rebuild kits available, but some (or most) of them seem to have the wrong parts. That is a concern, I'm in Canada so it's harder to get parts (vendors won't always ship here) and they tend to cost more due to high shipping costs and be impossible to return. I will have to talk to the local engine rebuilder to see what they have to say. It looks like it's easy enough to source some parts through Rockauto and they're cheap enough to gamble on, as long as you don't need to go to oversized pistons, if you need them it looks like it's a rabbit hole at that point. Also a lot of the kits seem to list as having cylinder sleeves, I wouldn't have thought this engine used sleeves from the factory so there likely is some shenanigans going on there. It would be tempting to do a compression check and throw my borescope into the cylinders before buying, but I don't know how much patience the seller will have for that. I'll have to look into carb rebuild kits too, but I can always get it to work with something else, like you said.

Good to know how the auxiliary works and the float. I didn't know anything about the auxiliary and planned to just ask the seller. Float makes sense, works the same as my mini tractor.

The main hydraulic pump was recently replaced, I plan to ask more about that, but I'd like to think they cleaned everything up when they did that. The engine compartment area does look clean by equipment standards. How hard is it to lift the cab on these?

He's had the bucket on and off (has photos of it both ways and I asked to make sure its included) so I'm guessing the quick-attach stuff isn't seized.

Thanks again for all the pointers.

The walls are thin on those engines already and they are likely to have to be sleeved because of the amount of boring it takes to clean up the cylinders. So don't let that worry you. Just did a toyota that way.

 

[2drx4]

The walls are thin on those engines already and they are likely to have to be sleeved because of the amount of boring it takes to clean up the cylinders. So don't let that worry you. Just did a toyota that way.

Yeah, I just wasn't sure if those kits are correct. I am familiar with the process, not sure what the local machine shop charges for it. Honestly I forgot to call them about this, I've had a busy last few days.

Going to look at the machine in about an hour though. So, we shall see.

 

[2drx4]

I went to look at it and it refused to start. He did show me a video if it running from the day before, which is rather academic to me. It didn't even attempt to start, no farting or popping or anything. So either no fuel, way too much fuel, or no spark. I honestly didn't feel like even checking for spark.

He knows nothing about it and said he bought it without looking at it in person and had it delivered, was told it smoked a bit and used some oil from the guy he bought it from, realised it was garbage and put it in his shop with 8 million other things. Knows nothing about servicing it or service history. He backtracked on it having a new hydraulic pump on it, he just knows it had a new pump of some sort (guessing fuel, looked shiny). It leaks everywhere and looks like something that was used like the easiest lay in town. He's moving, needs it gone. My gut says not even with a 10 foot pole. My heart says give him a lowball and winch it onto my trailer so it's now my problem.

 

[2drx4]

Do moderators ever approve posts? What a stupid policy when clearly somebody isn't a random spammer.


I wound up getting the machine running and buying it, BTW. It's still on my trailer, but I'll get it off and into the shop soon. I need to buy a manual for it now I guess.

 

[Chris 8603]

Well good luck with it, you must have offered a price he couldn't refuse!!! Hopefully everything will go your way and you'll have a good machine. Post some pics of your journey for everyone to see. Good luck!!!

 

[wings5j]

Do moderators ever approve posts? What a stupid policy when clearly somebody isn't a random spammer.


I wound up getting the machine running and buying it, BTW. It's still on my trailer, but I'll get it off and into the shop soon. I need to buy a manual for it now I guess.

Hi,

I bought a 742B in 2007 with less than 2,000 hours on it (if the hour meter told the whole story). Similar to you, I am an aircraft mechanic as well as some background as an auto mechanic and farm mechanic. My full time job the past many years has been as a pilot.

I just use my Bobcat on our property; plowing snow every winter, moving rock and sand and gravel for various projects, and also a little bit of logging. It has been a great machine and still doing well but has received a lot of TLC and new parts over the years.

Brdgbldr gave a really good rundown as well as some of the others on the forum.

As you just mentioned, getting a service manual and parts manual will be invaluable. I believe this site has links to some pdf downloads if you aren't able to get OEM hard copies.

If there is any steering creep it is possible you can adjust it out but be prepared to buy some of the steering parts. You will need a good set of 4 jackstands to have it off the ground while doing the steering adjustments. You can do it yourself but a helper makes it simpler.

There are several good threads on the forum related to the 742B for individual tasks, including tips on greasing the "U" joint (it has 3 zerks fittings. You can get them in the optimum location by using a socket and breaker bar to turn the engine over by hand. You might want to use your flashlight and inspection mirror to find them them the first time, you will need a 24-30 inch hose on your grease gun to make the job easy. The maintenance schedule recommends doing this every 250 hours. I also find it helpful to use a pad so I can lay on my belly on top of the hydraulic pump to be able to reach in and connect the grease gun hose.).

Good luck, I look forward to your updates. Sorry I'm late to the party but I will keep an eye out going forward.

John

 

[Dave1234]

Do moderators ever approve posts? What a stupid policy when clearly somebody isn't a random spammer.


I wound up getting the machine running and buying it, BTW. It's still on my trailer, but I'll get it off and into the shop soon. I need to buy a manual for it now I guess.

Can you give us an update on what you found and what it took to fix it? All of us with similar machines really appreciate hearing the details of a fix we might need to do in the future.