I was trying hard to talk myself into buying a new 661 because I've had good luck with Stihl saws in the past. (009, 026, 044, 461) However, After quite a bit of reading and asking some questions, I decided to go with the 390. Yes, the 390 is a 10-11 year old design but I felt Stihl hasn't worked out all the bugs quite yet.
Here are some of the notes I've collected/copy-pasted on the 661 from (Edit: *********) and it's members. It's pretty random/slapped together but you'll get the idea.
Pat
661 Notes
boot "straight boot" =
1144 141 2202 retail $20 (intake boot) (Solid vs Bellowed...Solid is better...washers were for bellowed boot to give it more strength, do not use) Gas cap IS NOT the problem...intake boot would collapse under vacuum without washers.
Coil: new coil "4701 A" on the actual unit. Stihl part # =
1144 400 1420 (Control Module...old one causes it to bog) This new coil "control module" fattens the saw up a bunch. The bog was caused by it being too lean on the low side.....(The new control module is
1144-400-4720 ???)
per stihl tech
"4700 C" & "4700 D" allow the saw to go too lean. They are warrant-able. Meaning if you make a stink like it's not running right. They will replace it with the new "4701 A"
"4700 E" is good and not warrantable.
4700E and 4701A have higher fuel values than 4700c 4700d.
Reset per stihl tech -
1. start saw on choke. let it run on choke 90 seconds. switch OFF. note: I personally hold the saw and keep the chain brake off cuz the chain likes to run just a little)
2. now restart saw and just let it idle. Don't touch throttle at all. 90 seconds of idling. then switch OFF
3. restart saw and make at least 5 cuts. You will feel the saw change for each cut...kinda cool.
Yes Sir.
1. Solder all wire connectors
2. 90 seconds on choke, then OFF
3. 90 seconds idle, then OFF
4. Cut big stuff
I've found a large amount of varying resistance throughout the harnesses. Soldering took away the pesky gremlins.
I've seen a bunch of these, and in one or another I've come across bad connections at just about every connector if you combine them all.
I make sure to solder everything, make sure its got the 4701 coil, and the straight boot, no problems after them steps yet
I like to put a small 20* bevel on the intake side of pistons on the skirt....instead of the sharp edge scraping the oil off the side of the cyl the bevel seems to hold it in better....also I think it helps with the incoming rush of air and fuel into the case....plus if you bevel it to half the thickness of the piston it doesn't change intake timing.....jmo