If you have the used parts, and nothing else is busted, try fixing it. I had one that did the same thing. I installed a bunch of used pieces, and it is still running now.

Possible whoever had it apart did not get the link on its anchor when re-assembling and the link thrashed around breaking into pcs. Check for other damage. These should be readily available used from small engine shop. They do not routinely fail while the counter weights themselves, do. The bearing of the counter weights wear out as does the eccentric they ride on. The counter weight bearings are not replaceable.

Walt Conner

The bearings on the counter weights look like
they have been hot and the cam gear cut a grove
in the bottom 1/4 of the counter weight. How do
you check to know if the bearings or eccentrics
are bad.I am going to the local junk yard today
and will try and find another 11 HP for parts.

Well that is a pretty good indication that they are bad and IF bad enough, that can cause the problem with the link you mentioned.

The counter weights are not repairable, Luckily, the eccentrics on the 11 hp engine are removable, IF it is a 25 series 11 hp.

You may have a problem finding good counter weights and eccentrics in a junk engine that old.

Good luck,

Walt Conner

Thanks for the information and advice. I think
that I will store this 11 HP till I find parts
and try and see if the 8 HP or 18 HP will adapt
to this rider . It is a 38 inch cut Noma rider that
I bought for $25 for parts but now our daughter is
buying their first house and they need a mower to get
them past this summer.

Thanks again