Stihl FS400

[Essexboy]

My brothers fs400 runs well until it gets to about half a tank of fuel, then it stops, its had a new coil, new plug, fuel tank is clean, new fuel filter, fuel pipe's are good new fuel bulb and the carb cleaned and fitted with new carb kit, again it will start OK and then die after half a tank of fuel (it seems) I have been working on engines for over 40 years but this one got the better of me, any help on this one would be welcome.

when it does stop if you remove the plug it is dry so its fuel related..!

[Millbert]

Any other wiring that could be cause?

[Essexboy]

Wiring from the switch to the coil is like new and find no problems, had meter on the kill switch no problems there.

[MATTMOSS]

I would change the fuel pipe to count that out All together

[Millbert]

Let us know if you sort it. I think with your experience you'll crack it!

 

I hate these mystery problems. Had same with a saw and it was hairline crack in plug.

[Essexboy]

I am happy with the job I done on the rebuild carb but I have ordered a new carb and fuel pipes to see...! its on its way and will be here next week, I'll keep you all posted.

[spudulike]

Split fuel line, possibly the breather is blocked, if the fuel cap is left a little loose, does it still stop? Check the coil to flywheel gap, a too large gap will fail when hot!

 

Check the continuity of the HT line with a multi meter.

[Essexboy]

Split fuel line, possibly the breather is blocked, if the fuel cap is left a little loose, does it still stop? Check the coil to flywheel gap, a too large gap will fail when hot!

 

Check the continuity of the HT line with a multi meter.

 

Thank you Spudulike it as a new coil from Stihl and the gap is spot on, and the fuel line looks alright but I have ordered a new one.

[Essexboy]

Update....took another look at it yesterday and would you adam and eve find that the fuel filter pipe was pig tailed and filter was not seating at the bottom of the tank, it run on a 1/3 of a tank of fuel and didn't stop, so filled the tank up and run again, all seems well at the moment, brother going to work it next week to give longer run, such a simple thing.

[MATTMOSS]

I just knew it would be the fuel pipe

Glad you got it sorted:thumbup1: