The 630 Jonsered can be anything from mild to wild from the factory....If you have one that is lacklutser powerwise then either it has the small carb and/or needs a rebuild. In my experience the thin rings suck...Jonsered tried this on a number of different models at around the same time...they all sucked....they were an effort to minimize friction and up efficiency...all they realy did was have more blowby and easily become stuck from carbon buildup...there is a reason they don't stihl do it and you can't buy a replacement thin ring to save your butt unless you find some NOS ones that someone got stuck with.. That said I like the 630...you can build them with either a single 1.5MM ring or two 1.5MM rings....with a bit of porting and MM the gains are very noticable. They are an older design and as such a bit heavier than your usual 61cc modern saw (which does not bother me much as I don't have "stick" arms..LOL) As far as handling goes, I find them to handle very well with an 18", fair with a 20", and not so good with a 24", not talking the power to run them just the handling. Of course the staight top handle that throws everyone into fits over, I feel is perfect...but in fact many of these have been pinched or run over and are bent back anyway!! As you can see by my sig I have this family in alot of it's variations ( with two more being built now) and have them in all the handle variations, straight, slanted and straight full wrap. I never give it a thought... they all work fine for me. I'm usually to busy cutting to worry about such things. Of course this is just MHO.....others may differ...
