Mysterious missing bolt on B2620 cylinder head

[seapea]

Looking in the engine compartment today of my B2620, I noticed a place on the cylinder head where a bolt is missing. I'm pretty sure there used to be a bolt there, because the area that the bolt head would normally cover is now rusted, as are the threads inside the bolt hole. If there was never a bolt there, it would have been painted gray.

I'm guessing the bolt hole is for mounting something onto the cylinder head, but since my tractor is running fine, probably nothing is mounted to it for the B2620, and instead normally there is just a bolt there to fill the hole. Probably worked itself lose and fell out. If that is the case, I can't figure out the part number. Below is parts diagram of the cylinder head. The bolt hole I'm talking about is circled in red. Anyone have any idea what part number goes in the bolt hole?



thanks,

Chris

 

[sandyc]

Just went out and looked at my 2620 and there is a "hole" cast into the head that might have been threaded in another life. Can't see any threads so I am guessing that there was never anything there on the current 2620 units. Thinking it might be a leftover from another model using the same head. Wouldn't worry about it!

 

[BeezFun]

The bolt hole I'm talking about is circled in red. Anyone have any idea what part number goes in the bolt hole?

Interesting that assembly 030 includes parts 040-080, none of which would seem to be part of an assembly. And 030 points almost right at the hole you're asking about. Maybe that hole was used to facilitate assembly of the engine, screw in some kind of little fixture to make it easier to lift the head into position during manufacture.

 

[SPYDERLK]

Looking in the engine compartment today of my B2620, I noticed a place on the cylinder head where a bolt is missing. I'm pretty sure there used to be a bolt there, because the area that the bolt head would normally cover is now rusted, as are the threads inside the bolt hole. If there was never a bolt there, it would have been painted gray.

I'm guessing the bolt hole is for mounting something onto the cylinder head, but since my tractor is running fine, probably nothing is mounted to it for the B2620, and instead normally there is just a bolt there to fill the hole. Probably worked itself lose and fell out. If that is the case, I can't figure out the part number. Below is parts diagram of the cylinder head. The bolt hole I'm talking about is circled in red. Anyone have any idea what part number goes in the bolt hole?

thanks,

Chris

P/N 0804941 Travelers Grease from TSC

 

[kuboman]

They make these engines to work in a multitude of applications hence the number of bolt holes that are not used in your tractor.

 

[oldballs]

I with BeezeFun. My B2620 has the same rusty hole. And it looks like the water pump sits about 3/4 inch in front of the hole. I'll bet there was and "eye" hanger there in the original assembly line manufacturing.....or ditto with kuboman.

 

[seapea]

Interesting that assembly 030 includes parts 040-080, none of which would seem to be part of an assembly. And 030 points almost right at the hole you're asking about. Maybe that hole was used to facilitate assembly of the engine, screw in some kind of little fixture to make it easier to lift the head into position during manufacture.

030 is pointing to the Cylinder Head. There appear to be two 030 part numbers. One is just the Cylinder Head, and the other is the Cylinder Head plus parts 040 to 080.

 

[seapea]

I with BeezeFun. My B2620 has the same rusty hole. And it looks like the water pump sits about 3/4 inch in front of the hole. I'll bet there was and "eye" hanger there in the original assembly line manufacturing.....or ditto with kuboman.

Ok. Good to know I'm not the only one. However, I'm still suspicious that there was once a bolt in there just to plug it up. The engine is painted gray after most assembly, thus when you look at it you see a bunch of painted over bolts. I would expect this bolt hole also would have received paint. Maybe because the inside was not painted, the rust eventually spread to outside the hole.

 

[s219]

That looks like a machined boss. They sometimes machine the mating surface flat and tap the threads after painting is done, which is why it was raw metal and rusted. I see these all over industrial diesel engines, which are setup to accommodate multiple different types of mounts and accessories.

If you look closely, you should see machining marks from a milling bit that is used to clean off the surface of the boss and flatten it.

Here's a shot of some machined bosses on the diesel engine that runs my generator:



Machining was clearly done after the engine was painted.