Stihl 261 mtronic hard starting when hot

[Sawhog]

Stihl 261 mtronic won't start after it's hot. Fuel solenoid and reset did not fix it. Has anyone used a richer mixture and found that it helps the starting after it's warm?

Edited May 29, 2021 by Sawhog

[Stubby]

6 hours ago, Sawhog said:

Stihl 261 mtronic won't start after it's hot. Fuel solenoid and reset did not fix it. Has anyone used a richer mix 80:1 and found that it helps the starting after it's warm?

I would have thought it is vapor lock if the weather is warm .

[Bob_z_l]

6 hours ago, Sawhog said:

Stihl 261 mtronic won't start after it's hot. Fuel solenoid and reset did not fix it. Has anyone used a richer mix 80:1 and found that it helps the starting after it's warm?

I had this.   Fuel solenoid, new filter and plug sorted it out.
Not had a problem since. Fingers crossed...it's my go to saw. I'd be lost without it.

 

[peatff]

6 hours ago, Sawhog said:

Stihl 261 mtronic won't start after it's hot. Fuel solenoid and reset did not fix it. Has anyone used a richer mix 80:1 and found that it helps the starting after it's warm?

 

The standard mix is 50:1, 80:1 would be less oil

[Khriss]

2 hours ago, peatff said:

 

The standard mix is 50:1, 80:1 would be less oil

Think he meant 40:1 . K

[Stubby]

1 hour ago, Khriss said:

Think he meant 40:1 . K

Don't see how more oil is going to help it start when hot .  Its vapor lock surely .

[topchippyles]

5 hours ago, Bob_z_l said:

I had this.   Fuel solenoid, new filter and plug sorted it out.
Not had a problem since. Fingers crossed...it's my go to saw. I'd be lost without it.

 

Google maps on your phone these days if all else fails 😆

[ChrisNewport]

80-1 id be whipping the exhaust off for a peek

[spudulike]

Difficult to say but would start looking at compression - guess you can't measure it so pop the muffler off and look at the piston.

I would avoid using the decomp when starting it hot, that may help otherwise it may be fuel related so check the gauze strainer, pump diaphragm and metering arm height etc.

Worth checking the tank breather as well, they do get blocked.

I have found that you can often start these AT saws with no choke when hot so worth giving this a go.

[Paddy1000111]

1 hour ago, spudulike said:

I have found that you can often start these AT saws with no choke when hot so worth giving this a go.

I've always started my 261 hot with no choke, just in the run position. I have found that putting in the decomp when hot can be annoying and effects starting like you say. Let's face it, if you need the decomp on a 261 you probably shouldn't be using it 😂