do you guys think a 20 inch bar on a sthil 271 would be ok
It's a stretch for a 50cc. I would go 16-18 on that saw. Also, depends on the wood you're cutting. If it's all pine, deadwood, soft wood etc you could use a 20 probably. If it's hardwood don't even think about it.
Should be .325 pitch. I'm not familiar with the 271, but I recently got a new to me echo 490 that came with a 20" bar. It's a 50cc saw also. 20" isn't my first choice, but it suits my proposed use well enough, and pulls it ok. Stihl specs a 20" bar for that saw, but I'd consider it suboptimal, same as the echo.
Not a stihl guy either, but if it's 50cc saw in good tune it should pull 20" fine. I ran a husky 450 as my main all purpose saw for years with a 20" bar and it worked quite well. Still have that bar on there with an Xcut chain now, even better. I rarely buried the bar except bucking larger logs. I asses a 562 to my harem and prefer that now for bucking (also 20" bar). The 450 with a 20" bar saved some bending for firewood work, which I do a lot of.
I had a 291 with a 20" bar that did OK, but eventually I decided it was underpowered. I bought a 362 with a 20" bar and a 261 with an 18" bar. I think you will be disappointed with the 271 and 20" bar.
My dad has had a 271 for years and i have the 291, they are not pro saws. I wouldn't put a 20" on it and expect to perform. My 291 likes the 18" bar.
thanks i guess i will stick with the 18 inch i have on there now