Stihl ts400 saw hard starting

[Shaun Dolman]

I have finally rebuilt my ts400 stihl saw and its runs and sounds great .

New main bearings , new crank, piston and barrel .

The trouble I am having as that it takes about 10 pulls to start it from full choke and then I take it off chock and it runs perfect and ticks over fine .

Surely it shouldn't take this many pulls to get it started . I have changed the plug as well just in case .

It's like because it's doesn't have a bleed for the petrol it takes around 10 pulls to get the petrol there but once started it's perfect .

I did take the carb of and cleaned it and also changed the fuel filter and fuel pipe why I was at it .

Maybe I need a new carb but it does run perfect once I have pulled it 10 times .

[MATTMOSS]

Ive got one thats a bit tricky to get going, ive got to pull it until it fites then put it on half choke or it just wont start. :confused1:

[Breezeblock]

is the breather on the tank ok has it got plenty of fuel in it without sounding cheeky

[MATTMOSS]

is the breather on the tank ok has it got plenty of fuel in it without sounding cheeky

 

You cheeky bxxxxxx!

Good point, could be something as simple as that.

[spudulike]

The breathers on most stihls are one way and let air in but don't let air out and generally has the effect of keeping positive pressure in the fuel tank meaning that it is easier to start. If the breather isn't working this way, you will have to pump the fuel up and 10 pulls sounds about right.

 

The other suggestion is that the low screw is set a bit lean and it needs a certain amount of fuel to get in to the engine to fire.

 

Apart from that, make sure the choke seals 100% when engaged and the fast idle does cock the throttle valve open sufficiently - normally it would be enough to produce around 1/4 throttle speed when starting and would equate to 4-5000rpm.

[JacobPitts]

I have a TS400. It wouldn’t run or when it did it was very lumpy. Installed new air filter and plug and carb kit and it ran good. Until my step dad took it on a job and wouldn’t start. Since then it’s been hit and miss. Sometimes starts sometimes doesn’t. Can smell fuel though. When it’s running and shut off it won’t start warm again and now can’t get it to fire. Any ideas?

[spudulike]

Low compression or main bearings. Owners don't look after the filters, stone dust is incredibly abrasive and this destroys pistons, cylinders and bearings.

Check the compression, you need 150+ and check the main crank bearings for play.

[Ratman]

My last one was gone on crank seals, wouldn’t hold pressure, fortunately it hadnt wrecked the crank or the bearings. Replaced them anyway, the bearings that is as tore it all down fully, piston was “ok” so just cleaned it up and fit a set of new rings, cylinder was “very” good which surprised me a bit, stuff usually goes hand in hand wear wise. Replaced the impulse line at same time along with carb kit and filters, she does a lot of work for me on the quiet so gota look after her and keep her sweet! [emoji108]

Still knocks socks off the newer 410’s etc in my opinion.

 

[spudulike]

Is it me or is the site rife with first posters asking for help and then disappearing in to the distance...perhaps they start the job and then got Covid 19 or perhaps as Elton DIDNT say...Thanks seems to be the hardest word!  

It is beginning to grate a bit - not how I was brought up!

[waterbuoy]

6 minutes ago, spudulike said:

Is it me or is the site rife with first posters asking for help and then disappearing in to the distance...perhaps they start the job and then got Covid 19 or perhaps as Elton DIDNT say...Thanks seems to be the hardest word!  

It is beginning to grate a bit - not how I was brought up!

It isn't just this forum Spud - I also frequent on that is car related and we are seeing a huge influx of first-posters who are looking for help and disappear into the ether.  Suspect it will return to near-normal once they all go back to work