promac850
formerly promac610
I used my 610 Saturday, and in general it seems to bog down too easily. I have done the carb adjustments, seems to run fine, just not much power in the cutting as I have read in other testimonies. So I'm thinking this would be a good candidate for porting and a muff mod. Any advice or wise words specific to this saw before I start? Appreciate any help.
Check the compression, and also check it the spark screen is clean.
Are you sure you got your carb tuning down right? If you are, then a carb kit and possibly a fuel line and filter is needed. Mine got that treatment last year, and it sure helped. It wouldn't even start after being stored for God knows how long with stale mix in it. So that little tune up woke the thing right back up, and it responds properly to tuning and does not bog down at all, even leaned on, with the 20" bar buried in hard wood.
These do not have a muffler in the sense we all are used to on Huskys, Stihls, etc. It's just a hollow metal box to redirect flow, and all it's capped off by is a spark screen.
I planned on porting one, but I heard they don't like to run over about 12,500 rpms... some guys mentioned they tend to grenade when run up there, even if it's tuned properly.
I imagine a carb kit may be all you need to get her going strong again, unless the rings are worn and it has low compression.