Bearing plate / blower housing differences

[sorekiwi 761]

I've just been trying to fit a blower housing off a recoil start K161 onto a K181. And it doesnt want to fit...

It fits really well on the K161 bearing plate, but just wont go onto the 181. I always thought the bearing plates were the same on all the small block engines. The only difference I noticed was the 181 had dowels to locate the coil (magneto) whereas the 161 didnt.

Anyone else run into this? Guess I gotts pull the flywheel off again and have a look, and probably just use all the 161 bits.

[WH_Hobie 1]

when we were rebuilding my 161 we put a different bearing plate on it and flywheel. but the blower housing that was on it at first won't fit now

[TT-(Moderator) 1,131]

When Kohler changed magneto styles from the magnet rotor mounted on the crankshaft to the magnets mounted inside the flywheel, the flywheel became a little larger. The bearing plate and blower housing also grew slightly to match the increased flywheel diameter. The difference isn't much more than about 3/32", but it prohibits using an older blower housing on the newer bearing plate.

edit: changed above dimension to 3/32" - I had 3/16" for some odd reason. Too early in the day, maybe? :USA:

[sorekiwi 761]

Well that blows, but makes sense too. Thanks guys.

The difference in mine seems to be like 1/16", close enough that you cant see whats wrong, but far enough away that there's no way you can make it work.

Oh well, I wanted to take some of the end play out of that crank anyway....

[sorekiwi 761]

How to change the bearing plate without draining the oil:

I found out the PTO side seal leaks... <_<

For reference the K161 is on the left (blue), the K181 plate is on the right (red).

I really wasnt able to get any good measurements to distinguish the two, and the only differences I could see is that the K181 plate has a part No cast into the back (visible in the last photo), and also has pins to locate the coil, as mentioned above.

I wish there was an easy way to identify them, it will catch someone else out at some stage.

By the way, the motor ran OK, not a smoker, so I'll probably pretty her up a bit and use it on the Lawn Ranger.

[linen beige 14]

It appears that the timing mark sight holes are not in the same place.

[sorekiwi 761]

It appears that the timing mark sight holes are not in the same place.

Good eye Jim, yes they are indeed in a different place.

Which opens up another can of worms... I guess I have to make sure I am using the correct flywheel, since the timing marks must also be in a different place.

This was supposed to be a simple "see if she runs OK, if so paint it and put it on the tractor" exercise, which is turning into another time consuming chore....