diagnose my problem with saw

[steeltowninwv]

my 460 starts easy...and as long as i stay in the throttle..its fine...but if i dont it dies.....sometimes on restart i have to feather the throttle but when it gets reved its fine.........fuel filter?..carb?...im gonna take it to the shop friday...just wanna get an idea if this is gonna be an expensive fix

 

[quads]

Idle speed adjustment. Turn the idle up a little.

 

[HittinSteel]

Yes, turn idle speed screw clockwise until the chain starts to move, then back off 1/8 turn

 

[steeltowninwv]

should i adjust idle when the saw is cold?

 

[quads]

should i adjust idle when the saw is cold?

You can, at least to start with, but then it may need a final tweaking once it's warmed up.

 

[MasterMech]

should i adjust idle when the saw is cold?

You can but you'll most likely want to re-adjust once the saw is up to temp.

 

[Whitepine2]

Might check the fuel line for a leak saw will run when trigger is pulled but stop at idle or slow speed. Just had this trouble with mine sometimes runs O.K. then no good will drive one crazy but it was gas line in the end.

 

[ScotO]

that sounds more like the low idle mix screw to me, given the fact he has to "feather' the throttle to start it. Sometimes dirt or other crap gets in that low idle mix and you gotta move the screw back and forth a little to get it cleared out, and then retune the saw. Just did that for a guy yesterday who brought his saw down (an old little Homelite 240), had the exact same problem. Ten minutes later and a little tweaking, problem solved and his saw was running better than it had in YEARS.......

 

[ScotO]

You can but you'll most likely want to re-adjust once the saw is up to temp.

+1. As a rule of thumb you should do two things BEFORE you try and tune your saw. First, clean the air filter out very good! Second, warm the saw up for 2 to 3 minutes, THEN tune it. That's the only way you should tune your saw.

 

[steeltowninwv]

adjusted the idle and now it runs great..i thinkits this weather change or something..cause my 170 did the same thing...same fix..idle screw

 

[Pallet Pete]

The idle screws will walk a little over time at least on any saws I have owned. I clean and check my saws after every tree clearing and on occasion I have to adjust the high and low mix ( not to often though ). Keep an eye on them and see if they move if they do check the springs on the screws if you have them and replace them if they are worn out too.

Pete

 

[smokinj]

Mine was doing this yesterday.......Its much warmer out now retune your saw I had to lean mine out quit a bit. It was not the idle screw it is on the "H" screw just running to Fat!

 

[skfire]

Seems. people have been finding that carbs and fuel lines get destroyed by ethanol.
If screw adjustment in Carb does not fix it, heck for hole in fuel line.
Then the carb may be a goner
Happened to one my stihls(290).

Scott

 

[Flatbedford]

I has similar problems with my MS180. I cleaned the air filter and what I could reach of the carb with out taking it apart. When I reassembled the saw it ran great. I never saw a clog, but there must have been something somewhere. My 036 was behaving like that too. I cleaned the air filter and replaced the fuel filter. I'll have to check the idle speed next time I use it.

 

[Researcher1]

I had been cutting in temps under 30 degrees for a while and my ms390 was running perfectly. This past weekend I had to adjust my idle to get it back to where it needed to be. My 261 didn't seem to be affected.

 

[greg13]

One other thing to check if all the adjusting does not take care of it, is the seals. I used to cut a piece of inner tube and seal off the carb & muffler (use it in place of the gaskets) then use LOW pressure 3-5 PSI and drop the saw in a bucket of water and look for bubbles. The use a vacuum gauge, pull a vacuum and make sure it holds it.

 

[Angelo C]

lots of good advice above. Check all and then break down carb and spray some carb cleaner through the hi-idle passage and the intake section as well. I had a 024 recently with same symptoms after new fuel line was installed. Cleaned out carb and good as new. Not even a rebuild kit needed. just some crud in the needle/seat area is all it takes. Oh, clean the needle tip off well too. should have NO wear signs or "rings".