743 Repair Questions - Bob-Tack, Coolant Tank, and Engine Connections

[Phikapjames]

Picked up a 743 and as I'm currently working through it. The first main question is if anybody has some good detailed pictures they can point me to of the engine compartment so that I can see where things that might be missing might go and be routed.

The first question is on the bob-tach, which I have the old 40's style. Pin was correct and apparently they used it for a while. On this piece, is the fix to get a new pin (6703572) and two new bushings that needed welded on (6562642)? I can't tell if the pieces that are bent up are actually bushings or not. I know there will need to be some bending of the brackets to get them back in place. Pictures:

The second question is more for the pictures mentioned above. The coolant tank was removed at some point in time and I am picking a new one up. Now I'm just trying to figure out how they re-routed the lines since currently there are no coolant lines anywhere near that side of the machine. More pictures of that area:

Finally, I'm curious if there should be lines coming off of the following places on the engine:

(the top of the engine, line pointing down)

(center of picture)

 

[OldMachinist]

Old style Bobtach bushings.

Tube on valve cover is crankcase vent. Should be a rubber line on it to direct blowby to bottom of engine bay.
Fitting on side of engine should have coolant drain valve attached.

 

[Tazza]

Old style Bobtach bushings.




Tube on valve cover is crankcase vent. Should be a rubber line on it to direct blowby to bottom of engine bay.
Fitting on side of engine should have coolant drain valve attached.

Looks mostly correct, there is a hose missing from the breather on the rocker cover. There is usually a piece of tube that slips over the breather and stops just about the lower engine mount.
Looks like some wear in the pivot bushing, they all seem to go there. I cut the old ones out, machines new ones and welded them in.

 

[Phikapjames]

Looks mostly correct, there is a hose missing from the breather on the rocker cover. There is usually a piece of tube that slips over the breather and stops just about the lower engine mount.
Looks like some wear in the pivot bushing, they all seem to go there. I cut the old ones out, machines new ones and welded them in.

Thanks for the help. Tazza, I've ran across a ton of your posts which link to your old 743, but all those links are dead. Any chance your old 743 pictures are still posted somewhere else?

Last one this time is I've been tearing pieces apart and fixing things along the way, I did run into another one the engine I'm having tracking down though. What is this so I can fix it?

 

[Tazza]

Thanks for the help. Tazza, I've ran across a ton of your posts which link to your old 743, but all those links are dead. Any chance your old 743 pictures are still posted somewhere else?

Last one this time is I've been tearing pieces apart and fixing things along the way, I did run into another one the engine I'm having tracking down though. What is this so I can fix it?

It could be a temperature sender. The correct location is in the thermostat housing though. It really doesn't look factory.

 

[Mikefromcny]

Thanks for the help. Tazza, I've ran across a ton of your posts which link to your old 743, but all those links are dead. Any chance your old 743 pictures are still posted somewhere else?

Last one this time is I've been tearing pieces apart and fixing things along the way, I did run into another one the engine I'm having tracking down though. What is this so I can fix it?

I bet your temp gauge doesnt work. Its the sender for for the temp gauge. Its a must on kubotas as they dont tolerate over heating. The new gauge will come with the lead and that fitting.

 

[NYDiggerman]

I just did the rebuild on my 743 bobtach. You can buy the replacement bushings through bobcat. As always a little pricey. As Taz said if you have the facilities to make them they aren't difficult to make. The one thing to remember when you weld them in is they need to be parallel to the bottom pivot pins. As the bobtach rotates thru it's tilt the pins have to be in line or they will bind. My suggestion is to locate the new bushings on a new pin in the cylinder link. Tack them and tilt the bobtach out to see if it binds. If it does you'll have to do a little trial and error to get it right. Good luck

 

[Tazza]

I just did the rebuild on my 743 bobtach. You can buy the replacement bushings through bobcat. As always a little pricey. As Taz said if you have the facilities to make them they aren't difficult to make. The one thing to remember when you weld them in is they need to be parallel to the bottom pivot pins. As the bobtach rotates thru it's tilt the pins have to be in line or they will bind. My suggestion is to locate the new bushings on a new pin in the cylinder link. Tack them and tilt the bobtach out to see if it binds. If it does you'll have to do a little trial and error to get it right. Good luck

NYDiggerman - you are spot on. I stuffed up on one repair i did, it wasn't straight and kept tearing the rod off the rod end. Took a bit of work to cut it out again, but i got it rite second time around.