Below is mostly a copy and paste from the other thread...

Break-in... I let the engine run for a little over an hour at about 40% throttle with the first oil. I found lots of specks of silver metal in the first change. During the second break-in run I let it run at about 60% throttle for the first 15-20 minutes and then gradually increased the throttle over the next 40-50 minutes until it was wide open.

When I eventually increased the throttle to 100% the engine started running a bit rough so I eased up on the throttle a bit. I let it run probably another 10 minutes and tried 100% throttle...the roughness was gone and it ran fine...???

The motor bolted up pretty good, but I have an issue with the belt-guard not fastening down. The output shaft is longer than the one on the OE Briggs so it was hitting the guard when the guard was pulled into proper position...the area that it was hitting is a cup-like area formed to cover the end of the shaft. I took my dremel and cut a square hole in the end of that "cup"...the shaft protrudes through nicely...I will cover this with a tin-can or something if I feel the need to do so. The bolt that braced the belt-guard at the engine will not work...there is no corresponding bolt-hole on the Predator engine. But, with the hole cut into the guard for the shaft the cover fits snug against the side of the engine and there are two bolt holes that I think I can put bolts into and that will hold the flared edge of the guard...I think it will work quiet well.

The last semi-copy/paste from previous thread...

I ran two changes of oil through the engine yesterday afternoon and it's sitting with a fresh change of oil at the moment. I still got tiny metal glitter in the oil on the second change. I'm wondering if I should go ahead and do another break-in run with it or bring it home and see how it works in the garden. The only thing that hasn't been tested out is the transmission which has no fill-hole for grease.

Something I noticed when I unpacked the engine was that the On/Off switch was set to "On". It seems I've read a post or two where some switches have malfunctioned. I'm thinking that since the "Off" part of the circuit is a grounding switch that by moving the switch back to "On" after turning the engine off that it might take tension off the switch...saving the spring tension/contact for grounding/engine-stopping action of the "Off" part of the circuit. I have no idea how this switch really works so this is just a wild donkey thought of mine. :)

Ah well, that has caught up the 301cc Predator thread for the time being...I'll post later when the engine gets dirty.

Interesting, I just looked at my receipt and it shows the engine as being 10hp...???

I'll check the box when I get back to the shop and see what it says other than 301cc.

IMHO HP on small engines has been meaningless for quite a while now. cc at least gives something physical to compare to, but trying to work that back to HP is a waste of time. Enjoy the new engine.

Yeah, I found one "calculator" that put the 301cc at around 9.25hp. The online ad states it as being 8hp, the box itself only says 301cc, and the receipt says 10hp. One thing is for sure, it is a strong motor and worked great Saturday...now to recuperate from fighting with the tiller.<groan> I'm still trying to figure out how to till in a straight line...seems I'll hit a spot and it'll start veering to one side or the other...???

I've read that the difference in "HP" is the decal the OEM puts on them. e.g. I have a GT5000 which had the 22HP Briggs with the bad air cleaner several years ago. Warranty thing and Briggs gave me a new engine. Had to haul to a "certified Briggs repair shop" for the repair. I watched them remove the old engine and it was sitting side by side with the new one. Briggs had sent in a 26HP engine, totally, and I mean totally identical except for the decals. The shop owner was curious and looked up the engine numbers and all the parts, carb, etc. were the same. Whatever, I got a new engine with a good air cleaner.

Wild guess on tiller veering, check for bent or worn tines on one side which is deflecting you. If the tiller has a "reverse tine" position do it that way first, then go to "tines forward."

Glad things worked out with the 22hp for you. When I was reading through your message I figured it would be a displacement factor that had increased the HP but if all the parts were the same for the two engines then it must have been those high-tech decals. ;)

I like your wild guess on the veering issue...I'll look into it. I don't have a reverse-tine, only the forward-tine gear but I will give them an a good going over. Thanks for the feedback!