Has anyone ported one of these? I know it only turns like 7500rpm, but I'd like to have something that will pull a 25in bar alittle better. The exhaust port looks very limited, and the opening into the muffler doesn't have a lot of room for improvement either. I was thinking of widening the intake, exhaust on the existing cylinder and maybe lowering the bottom of the transfers. I'm worried about the 40yr old chrome flaking off after I cut into it. Thoughts?
I ported my 041 Super a little bit a few weeks ago when I tore it all down. Didn't do too much to the transfers; just smoothed them out a bit. I widened the exhaust significantly but didn't do as much to the intake. As you noted, it's pretty much impossible to do a really good port matching on the muffler due to the restriction of the pipe as it comes out of the mounting plate. I rounded that area off as much as I could though. I never took any pictures of this, but I have to tear it back down again here pretty soon, because I have a better case to build it around now. I'll take some pictures when I do that. It runs great and sounds amazing, but I haven't cut with it since modding yet because this case has a stripped bar stud mount. The new one is in much better condition. My #1 tip for working on these though is to make absolutely sure every nut and bolt are as tight as you can safely get them - and don't be afraid to use some blue Loctite here and there. My Super will throw 5mm assembly bolts all over at high RPM if they don't have a lock-washer or some threadlocker.
A strong 041 should pull a 25" bar just fine. At least I always thought mine did when it was 61cc. Once I get this Super rebuilt, I'm going to try it with the 28" .404 setup I have.
Here's the non-AV 041 I just rebuilt last week in action:
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It's no slouch, that's for sure! That's a 20" 3/8" full-comp chain, and IMO it has plenty of grunt to pull more if it needed to - I can lean pretty hard on it. And while I wouldn't really want to cut all day with it, it's not all that bad for either weight or vibes.