My slightly nicer but also terrible Bobcat (742B)

[Scott Cee AKA 2drx4]

Work was busy with dumb stuff (like, actual work), so I didn't get much done.

Glad I chose not to try running this pan gasket:

RTV'd the pan and then hosed the speed paint on it:

I tried to get a picture from the best angle. There isn't. It's hideous. I masked nothing and just used a piece of cardboard to cut down on overspray. It is glorious in how bad it is.

[Scott Cee AKA 2drx4]

The gasket annoyances continue. I bought two gasket sets for this thing to try to make sure I had everything. The Fel-Pro one is HS9874PT, and it only covers the head. The other one was made by Omni5 (no idea who that is) and is PWC-00302. The Fel-Pro one had a bunch of munched gaskets in it, but it was the last one in stock so I accepted it.

Here is the intake gaskets out of each kit:

The Omni5 is on top, Fel-pro bottom. The Fel-Pro gasket came torn and bent.

Each laid on there:

So the Omni5 one is wrong. It's close, but not right. I debated just RTVing the crap out of the water passage part that's wrong and running it. But I don't know if it's a good idea. The rest of it looks good enough.

P/N for the Fel-Pro one by itself is MS90410, but there is only some old stock out there on eBay. Doing more research, the Omni5 one is for a turbocharged car, the head is different, hmm.

I decided to order some other ones from RA. So we'll see. They won't be here for a while so yay.

Also when I had the engine upside down I noticed it was leaking from around the back here:

It turns out that half-circle plug from the Fel-Pro kit is too tall and too hard, so the rest of the valve cover wasn't sitting flush. I swapped it for the one from the Omni5 kit, it seems better, but I'm not sure. It may seat itself up more once it has run a bit. Typical crap design.

[Scott Cee AKA 2drx4]

Had some time to work on this again, because miraculously our helicopter isn't broken.

New intake gaskets came in:

Again, lots of last of stock stuff. So who knows. You can totally cut this gasket out if you had to.

The head has EGR provisions, so you can see right through it. Just a random comment.

Epoxied a stud in the carb:

Not a great repair, but it's good enough.

Thermostat:

That one has the jiggle valve and all that. Looks like it should work. The Bobcat part is NLA I believe.

Got some stuff bolted on:

Still got more odds and ends to sort out, but getting closer.

[Scott Cee AKA 2drx4]

Primed the oil system:

I used my multimeter to confirm I was tripping the oil pressure switch, so it is definitely building pressure just driving it with a drill. Plus I could hear it squirting around. So that made me happy. Always scared about pumps not priming on startup or whatever.

Timing (cam):

Timing this thing is simple. The cam gear has a dimple on it, you line that up with the notch on the very top of the timing belt cover. The crank gear has a dimple on it, plus there's on on the inside of the pulley that matches the one on the cogs (its for when you put the gear together, so you know they're matched). Those just point at the "finger" that's sticking out of the timing case beside them. You line those up, put the belt on, spin it over once, push the tensioner and tighten it. Very simple. Assuming I did it right again. Anywho.

[Scott Cee AKA 2drx4]

I guess I should have taken a better picture of the "finger".

[Joe_the_ice_man]

Maybe I'm a sucker for speed paint on four bangers, but I like it way more than i probably should

[Scott Cee AKA 2drx4]

Got it back on the mount:

It took me about 3 hours to clean all of the old oil and shit off the mount. It's amazing how bad this machine was. I still need to clean the engine compartment a lot more, not looking forward to that.

[Scott Cee AKA 2drx4]

Running out of excuses to put it back in the machine.

[Scott Cee AKA 2drx4]

Spent way too long cleaning this. Finally admitted I needed to pull the squirrely butt fan out to clean and repair it. I got about 50lbs more oil soaked mud out in the process.

Also, it turns out the pump drive is assembled wrong. So I'll have to fix that. And I found a hydraulic hose that's eaten up pretty bad. I hacked the heater lines out too because they were rotten and I don't think the heater works. I would like to install them differently, the way the factory did it is insane.

[Scott Cee AKA 2drx4]

I'm not sure what's going on with this pump drive. I suspect somebody matched the ujoints up with something in the Spicer catalog and went with it. I do endorse this, but there wasn't really a good way to assemble it because of that.

The u-joints should be lubed from the caps, not the body. There is no way to lube these with it installed in the machine:

Taking it apart there's evidence it was contacting:

I suspect this is because the engine mounts had totally disintegrated and resulted in the engine being too low. The pump mounts might also have been worn and drawn in so the pump is too high (it mounts from the top in the rear). Ultimately I just cleaned up the damage with a file and made some sort of audible comment about it being not just good, but good enough.

Back together with 45 degree zerks on it so you can grease it in situ:

Putting it together like this resulted in the bolts facing wonky and whatever. Is it right? Probably not. Does it matter? Probably not. In retrospect I should have drilled and tapped the caps that I needed instead of moving them around. Whatever. It's done. All of the grease zerks are supposed to be in a line so you can rotate the engine to the right place and grease them, they're not, and I committed the sin of moving caps around on joints that had already been in use. It's back in the machine now and I'm over it.

[Scott Cee AKA 2drx4]

I needed to fix the big squirrel fan shroud out and fix it before putting the engine back in. As you can see, it melted. Badly.

This isn't super right, but it's what I did. Basically, cut the damage out, make a patch, rough up the surfaces, put some bolts and washers through it and glue it with something that might bond to aluminum and plastic. I'm not sure what this plastic is, it's quite slippery, so I used some badly expired aviation product I had around (PS 890) and hoped for the best. I chose aluminum diamond plate because I did this on a long weekend and Crappy Tire was my option for materials, and I didn't want to use heavier steel. I should have put more bolts/screws in it, and I should have put an angled piece at the top and picked up on the flange for the opening above it. I wasn't in the mood so I didn't. This is way better than it was soooooooo

The other problem is that the cover for the access hole to get at the hydro oil cooler was totally missing. Without this the air doesn't get forced through the cooler, or through the radiator, so everything overheats. I have no idea what that piece looks like and you can't buy it, so I just decided aluminum would do again. Plus I didn't know how it attached, so I wound up putting a bunch of anchor nuts in it with rivets and everything.

My riveting skills have slipped, I don't do it as much, but I think it came out fine for not being anything that will (hopefully not) be flying. I'll probably have to adjust all the holes when the thing is actually bolted in, so I just went straight for the big assed penny washers.

[Scott Cee AKA 2drx4]

With the stupid fan shroud "fixed" I could finally put the engine back in.

Half in:

This seems unnecessarily awkward. Next time I think I'll leave the big piece off the top as it would be easier. It's odd that they welded the bar across the top so there's no way to go straight in. Anyway, hopefully I'm not doing this again, at least not soon. Oddly I didn't take a picture once I got it it in, just when I stopped to rerig to get it to go the rest of the way. Aligning the drive and pump wasn't as bad as I thought, I got it close before I jammed it in, then reached in from the left (if facing forward) side of the pump from the front and managed to get it aligned well enough, then I just turned the engine over with a bar and wiggled it until the splines engaged.

Another issue was the exhaust. The muffler it had was destroyed. The flex pipe from the manifold to it was the wrong one, and was cut down wrong so it couldn't seal. You can't buy the correct flex pipe, but I could buy the muffler and the wrong flex pipe for the same price as just the muffler, so I bought the wrong one and figured I could YOLO it. This was off Amazon and the P/Ns they list it being are "6677363 6569624 6514737 6575580", yeah, whatever, just search for 742 exhaust if you're some random googler who is reading this.

I started by doing some exploratory cuts on the flex pipe:

I knew I wouldn't need the curved part, so I cut it off. It was still too long (apparently I don't own a tape measure).

Then I wound up cutting it like this:

By cutting almost all of the end of it off, and shortening the socket it goes into on the muffler, I got it short enough. This may leak excessively, in which case I may pull it out and weld them together, but if I do that I will need to cut a bigger hole in the machine to get it through because the flange at the manifold is too big.

Installed and clamped:

I got some other stuff done up too. It's getting closer. I'm going to have to clean up the wiring too though, I went to put it back in and a couple ring terminals snapped off, so might as well face it and fix it now.

[Scott Cee AKA 2drx4]

I'm also confused why they put the battery on the right side of the machine, there is lots of space in the left, and the starter is there. I may just move it. I need some sort of hold down for it too.

Also I deleted the heater for now. I don't think it worked anyway. I just looped the hoses for it.

I still need to change the choke cable.

I need to build the heat shield that goes between the muffler and radiator. Again, might have had something to do with the machine massively overheating. Also a part you can't just get, so I'll spend a bunch of time making it. It looks like it should be simple though.

And I need to make a strap to hold the fuel and hydro oil tanks in place. I feel leaving them flopping around in there is asking for trouble.

Feels closer. Maybe I'll have it running before the last snow fall.

[Scott Cee AKA 2drx4]

P/Ns for the waterpump/alternator and governor belts:

Continental 15321 or 11AV800 (governor) and 15411 or 11AV1030.

I got lazy on the heat shield for the radiator. There is not much space for it in there, and the whole installation of the radiator is actually a total pain in the ass (more on that), so I resorted to some stick on heatshielding.

I think this will be "just as good" as the real thing. No, it won't be, I know that. It will probably be good enough.

I tried to install the radiator for good. It bolts in from the bottom. Well, it turns out the whole plate it mounts to is warped. Plus getting the bolts in from the bottom is absolute garbage. I will have to come up with some sort of pin mount or rubber mounts, or something like that. As it is if I tighten the bolts I suspect the whole radiator will split. This would partially explain why there was no bolts in it when I bought it. However, it does need to be secured somewhat at least, and some of the missing bolts hold the fan shroud in place. So, yeah, something else to figure out. Yay.

[Scott Cee AKA 2drx4]

I didn't really want to deal with the wiring harness, but a bunch of terminals were in the process of breaking off so I accepted I needed to clean it up.

I changed a few wires and removed a few others. Not sure what some of them were for, options that my machine didn't have or something. Anyway, it seems a lot nicer, I'll still need to clean the ends up a bit when I get it in. Some of the previous repairs to it had been total hackjobs.