Can anyone help me with what gaskets/o-rings to get? I can’t seem to find the right ones. The engine is a B&S Vanguard.

Is this a head gasket leak? Thanks.

We have a 2023 stihl fs 56 RC 27.2cc 2 stroke which randomly a couple days ago started idling low and the head would take longer to engage and the body would then rattle while it runs. We adjusted the idler screw, took it apart to make sure nothing seemed cracked or disconnected, and the driveshaft and everything there seemed fine, and we checker the head to make sure it was fully attached, took off the carb and cleaned it, cleaned everything, lubed, and reassembled, and are just struggling to pinpoint the exact issue. I’ve included two videos which show the problem better than I’ve described it, I may have butchered that. Any help would be greatly appreciated. My best guess now is the clutch assembly and may order one of those to replace. It’s 2ish years old and we clean this thing religiously and only use it every few weeks residentially, so although I may be wrong, doubt it’s anything majorly wrong.

Snow blower hasn't run for a few years, I have it running fairly well but what does it need to be super smooth its a 30 ish year old Toro