K161

[WheelhorseBob 1,550]

Fellas,

 

I have a 161 that has a .030 piston and is badly scored. It’s a 1961 vintage and dare I say not a Horse😬. Anyway you blokes never steer me wrong. I’m being told 161’s came in two different bore sizes? Is that a true statement? If so can the smaller bore be bored out to the upper end of a large bore?

[rmaynard 16,293]

12 hours ago, WheelhorseBob said:

Fellas,

 

I have a 161 that has a .030 piston and is badly scored. It’s a 1961 vintage and dare I say not a Horse😬. Anyway you blokes never steer me wrong. I’m being told 161’s came in two different bore sizes? Is that a true statement? If so can the smaller bore be bored out to the upper end of a large bore?

The K-161 did come in two sizes. 

 

Can't tell you about how large either one can be bored. I guess a lot would depend on whether or not over-sized pistons and rings are still available.

 

 

 

 

Edited January 4, 2022 by rmaynard

[ri702bill 9,396]

17 minutes ago, rmaynard said:

I guess a lot would depend on whether or not over-sized pistons and rings are still available.

It is my understanding that there are no oversized pistons nor rings available anymore for the early small bore K161's. Not sure IF you can safely bore the early blocks to the standard bore of the later style.

Bill

[squonk 43,778]

Might be able to sleeve it and go STD.

[Pullstart 66,690]

Wait up.  The 141’s and 161’s had identical bore and stroke?  What made the difference in power?

[ri702bill 9,396]

Just a guess with no actual proof (like that never happened here before !!) perhaps a smaller bore carburetor or less lift on the cam to keep the valves open for less of the 4 stroke cycle???

Bill

[Handy Don 14,054]

The Onan P218 and P220 get much of the 2hp difference from a slightly different cam