MS260: Idle slows when saw picked up

[DeanBrown3D]

Every time I pick up the MS260, the idle slows down (I'd guess around 50%). Not too fussed about this unless is starts stalling. Is this normal though?

Cheers,

Dean

 

[fishhuntcutwood]

Ya know, the same thing happened to my 660 today, although barely noticable. I took the same train of thought you are...

Jeff

 

[tek9tim]

Sounds like maybe your idle is a little rich, and fuel is building up in the bottom end of your saw, and when you pick it up, it jostles it around enough to make it to the transfers and into your top end. Usually what I do when I set my idle is to let it sit for a while after I think I have it right, then roll it over on its side to check for this problem.

 

[Freakingstang]

My 2186 was doing this yesterday. I think I do in fact have the idle to rich. I noticed it toward the end of the day. I will try to readjust and post the results.

 

[Simonizer]

Sounds like maybe your idle is a little rich, and fuel is building up in the bottom end of your saw, and when you pick it up, it jostles it around enough to make it to the transfers and into your top end. Usually what I do when I set my idle is to let it sit for a while after I think I have it right, then roll it over on its side to check for this problem.

I agree.

 

[DeanBrown3D]

Ok thanks all I'll make the adjustment and test it today.

But where exactly is the fuel supposed to be collecting?

Dean

 

[Lakeside53]

I mainly collects in the carb boot - a cold environment. A good test is to tilt the saw forward, and if it then slows down, rev it up to clear the puddled fuel - it should idle normally in the "odd" position.

If you can't get it to stop doing the slowdown when tilted, i.e. you can't get a good idle when not too rich, then it's often a sign that your crank seals are marginal.

Personally, I don't sweat it too much - I find a slightly rich idle makes for easier starting and better cold idle, and that there is often no "perfect" L mixture setting from day to day anyhow.

 

[ShoerFast]

Idle speed that varys as the saw is tilted (I call it roll-out) is from pooling fuel droplets that collect in the crank and x-fer ports. Picture droplets of rain on a windsheld, stationary as the car moves a certian speed, but if the car was tilted, the droplets would leave the windsheld.

It can be caused by a rich mixture, but sometimes by a mixture that is too course.
Sometimes people get in the habit of just turning the idle screw to reset the speed they want, but if they get the carb butterfly into the transfer slot, (just after idle) the saw will be idleing with a courser mixture, as transfer slot just dosant atomize the mixture as well as the "L" ajustment screw and jet dose.

To get the carb ballanced again, what works for me, is it needs to be leaned down till the chain starts to creep, turn the speed screw down and check the accereration,,,,, keep repeting that prosses intell the accelaration just starts to hesatate a little, then fatten the "L" about an 1/8 turn out then set your speed with the butterfly screw. I dont know if this explanation is understandable, or I'm etting my point accrosed? if it is, it should have your butterfly set just just forward of the edge of the transfer slot, idleing on just fuel from the "L" jet, with out to much roll-out idle speed change.

Kevin