Husky 257 problems

[03jeeptj]

My uncle gave me his husky 257 after I bought him a new 570, the 257 runs but when I try to cut anything with it it bogs way down and dies. I have had the cylinder off and have a new base gasket on the way, what else could cause this?

 

[Rockland Farm]

What made you decide to pull the jug off ? Did you go through the carb and fuel system first ? Give us a little more info .

 

[03jeeptj]

Sorry, I have went through the Carb and rebuilt it, I pulled the cylinder because I noticed mix leaking out from the base gasket after it was run, the piston and cylinder look good, except for two small scratches on the piston

 

[HiOctane]

Did you replace the fuel filter? Try opening up the H needle if you feel difference.

 

[03jeeptj]

I just did a tune up on the saw, new filters, Carb gaskets, fuel filter, it never ran right before this, when it idles it sounds fine, throttles up and runs great under no load, as soon as the chain hit wood it stalled

 

[SawTroll]

You didn't mention fuel lines and impulse?

 

[Rockland Farm]

Well the jug is off and you have a gasket on the way so your gonna do that now whether it needed it or not . Fuel leaks can fool you . You get the saw running and the fuel gets spread around making it tough to pinpoint sometimes . Do the fuel lines if you haven't already put the saw back together make sure everything is tight . Set the high and low to factory specs ( 1 1/4 turns out I think but double check ) and let us know what happens .

 

[03jeeptj]

The fuel line is good, where is the impulse?

 

[phillipmc]

The fuel line is good, where is the impulse?

There should be a 2nd line running from the carb to the saw "crank case" that is the impulse. If there is a pin hole or crack in it that will cause an air leak. or cause the carb to not pump enough fuel. The only way to really check it good is to completely remove it and bend it and such in different ways or vacuum check it while bending it in different ways because the leak may not present itself until the saw is under load. when a saw is under load the engine twist and moves slightly because of the AV system.

 

[ncfarmboy]

No impulse line on a 257. Impulse goes through carb to cylinder block. Fuel line is bad to crack right @ tank. Tank vent is another leak problem it's on the right side. They are prone to leak esp. when tank is full and turned on clutch side as fillling tank. Fuel coming from eitherspreads around the same area. If it's bogging in the cut it's a fuel delivery problem. Make sure the hole is clear in the intake block and the hole in the gasket is open. For a little boost in power you can delete cyl. gasket and use some ThreeBond 1194 or equivalent for base gasket. Check squish need around .025 or so.
Shep

 

[03jeeptj]

Thanks for the replies, ill go out and check it again when I get the chance

 

[514mach1]

I've got a 257xp also. I've replaced the fuel line twice now (went with Tygon last time so we'll see how long it lasts). The 'impulse' on these is as was mentioned, there's a little rubbery plug thing that goes in the cylinder which mates to a nipple on the manifold betwixt the carb and cylinder. Be careful tightening the two carb screws to that manifold... they love to strip out. What hasn't been mentioned yet is the muffler screen. Make sure it's not plugged up with gunky carbon soot. If it is, briefly "cook" the soot with a propane torch and then use a wire brush to clean the screen... both sides.

 

[SawTroll]

I've got a 257xp also. ....

There never was a 257xp. :msp_wink:

 

[514mach1]

Correct. I must have been thinking it in my head. Not an xp. Sure seems like an XP version of the 55 though!