No experience with LRB stuff. The Hyland pop-up kit I just got for a 261 is nice but I still had to clean up some casting spots in both intake and exhaust. Saw runs great. I have used Meteor in the past…equally good, maybe better but they are hard to find now.. I do have a 261 that was given to me that has what is obviously a cheap, eBay, Chinese P/C kit and it really shows. It runs…but not that well. Compression difference: 170, cheap vs 190, Hyland.
That said…what you have is a $1500+ saw…whole different animal. The difference in a top quality OE pist/cyl is well offset. Yes, there are cheaper alternatives but they are cheap for a good reason.
if all you are looking to do is get it running for personal use then the higher end aftermarket kits will be fine. Meteor and Hyland seem to be in that group…there may be others. If the difference, however, is under $200 don’t even bother with aftermarket, IMO.
OE tens to have a lot fewer casting issues and also tends to have more “meat”. Saw builders won’t attempt full porting on aftermarket cylinders for a good reason
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