854 air filter attachment question

[FLtractor 94]

Afternoon,

Have recently installed an afternoon carburetor while I send my original to forum member who can clean it much better than I have the tools and patience for. I noticed on the new carburetor, the 2 holes on left side that should hold the air filter housing in, do not appear to be threaded for screws.. wondering if anyone has any idea solutions for holding on the air filter housing. Have attached orignal carb and aftermarket carb photos for reference. 

[ri702bill 10,567]

Pretty simple actually. The holes are "as cast" in the bosses and should be the tap drill size for those 2 screws. Identify the screw size & thread pitch and tap the holes deep enough with the proper sharp tap... it may be necessary to drill them with the tap drill first.

Not being tapped tells me that the new carb MAY not be the correct one for an 854 - the largest carb bore on the small block K series Kohlers, It may have been meant for a 5, 6, or 7 HP motor - as those did not have that arm on the side opposite the choke lever...

Edited 7 hours ago by ri702bill

[FLtractor 94]

31 minutes ago, ri702bill said:

Pretty simple actually. The holes are "as cast" in the bosses and should the tap drill size for those 2 screws. Identify the screw size & thread pitch and tap the holes deep enough with the proper sharp tap... it may be necessary to drill them with the tap drill first.

Not being tapped tells me that the new carb MAY not be the correct one for an 854 - the largest carb bore on the small block K series Kohlers, It may have been meant for a 5, 6, or 7 HP motor - as those did not have that arm on the side opposite the choke lever...

I will have to check to see if I have a tap and dye set still in the garage. Apologies ment 856. 8 HP. 

[sqrlgtr 1,310]

1 hour ago, FLtractor said:

Afternoon,

Have recently installed an afternoon carburetor while I send my original to forum member who can clean it much better than I have the tools and patience for. I noticed on the new carburetor, the 2 holes on left side that should hold the air filter housing in, do not appear to be threaded for screws.. wondering if anyone has any idea solutions for holding on the air filter housing. Have attached orignal carb and aftermarket carb photos for reference. 

I have run those before without that support being bolted to carb without narry a problem. Of course, it would be better to have them in there but not absolutely necessary.

[FLtractor 94]

1 minute ago, sqrlgtr said:

I have run those before without that support being bolted to carb without narry a problem. Of course, it would be better to have them in there but not absolutely necessary.

What about using double sided tape? Or JB weld a screw inside the side bracket holes if I don’t have a tap and dye set

[sqrlgtr 1,310]

If it was me and I didn't want to tap holes I would just not worry about them . You can always go back and tap them at a later date. They should be easy to tap (soft metal), but I would use a "bottom" tap that are designed to tap blind holes.

Edited 19 hours ago by sqrlgtr

[lynnmor 8,252]

Personally I would tap the holes but another way is to buy a pair of self tapping screws.

 

Edited 17 hours ago by lynnmor

[adsm08 3,856]

I don't know about the rest of you, but those screws in mine are self-tapping. They look like this:

 

 

That chamfer in the end of the screw tip is a self-tapping feature, these can be turned into an un-tapped hole and will cut their own threads as they go.

 

Most people are more familiar with this style: 

This is self-tapping, but also self-drilling, it will make it's own hole and cut it's own threads. They other style will only cut threads.

 

There is also this style, which is mainly found in automotive applications post 2000:

 

 

The end is triangle shaped, they self-center and self-tap but should not be used with power tools, especially if being put into an already tapped hole as it is easy to put a second set of threads in it.

Edited 16 hours ago by adsm08

[sqrlgtr 1,310]

Fillister head is what was in mine.

[kpinnc 16,181]

10 hours ago, FLtractor said:

don’t have a tap and dye set

 

If you go with self tapping screws, just be sure not to use screws that are too big in diameter. The threads should be all that "cut" into the aluminum. Otherwise you can crack the body of the carb. 

 

10 hours ago, sqrlgtr said:

have run those before without that support being bolted to carb without narry a problem.

 

 

If the air cleaner attaches to the carb with 3 screws instead of just two- you really don't need the side support anyway. 

[FLtractor 94]

1 hour ago, kpinnc said:

 

If you go with self tapping screws, just be sure not to use screws that are too big in diameter. The threads should be all that "cut" into the aluminum. Otherwise you can crack the body of the carb. 

 

 

 

If the air cleaner attaches to the carb with 3 screws instead of just two- you really don't need the side support anyway. 

Will keep diameter in mind if I go self tap.. 

The air cleaner has 2 screws on front it attaches with .. and then 2 on the side bracket 

[ri702bill 10,567]

If you do go the self-tapping screw route - do hat by hand using consistent force and straight-on alignment.

As noted, they are primarily designed for a one time use - all too easy to cut a second set of threads and ruin the hole if not careful.

Your tractor, your choice...

[FLtractor 94]

4 hours ago, ri702bill said:

If you do go the self-tapping screw route - do hat by hand using consistent force and straight-on alignment.

As noted, they are primarily designed for a one time use - all too easy to cut a second set of threads and ruin the hole if not careful.

Your tractor, your choice...

Will keep that in mind. Thank you Bill