Sachs Dolmar wont start hot..Help needed ?

[Swarf]

I need some advice here.please, My little top handle Sachs Dolmar 100 will start and run lovely, but once hot ,,,,Nothing.

it needs choke to start but then runs until you switch off, then wont start until cold again.

I have checked cut out switch and s/plug but don't know where to go from here.

Would anyone have the answer? Chris.

Edited August 10, 2018 by Swarf
to add "help Please"

[peatff]

That's a rear handle not a top handle  Try resetting the carb to manufacturer standard, screw the H & L screws in then something like one and a quarter turns out on each. It could be running weak on the L circuit. 

[bmp01]

18 hours ago, peatff said:

That's a rear handle not a top handle

Ya.

That was my starting point too, then ......  way too many options.

 

Saw looks clean,  low hours I'd guess but what's compression like when its hot?  Pick up the saw by the pull cord - does it drop quickly unwinding the cord or can you pick up the saw and watch the saw drop slowly as the pull cord unwinds through each compression cycle?

 

What are you doing with the choke and fast idle when you attempt to start from hot?

 

Get a new spark plug in it. 

 

If you are testing for spark you need the spark to jump a 3 mm gap in fresh air,  do that with cold and with hot engine (heat soak the coil).  If you can't come up with a scheme or tester use a known good plug and bend the outer electrode to give the 3mm gap. 

 

What happens if you drop a  tiny bit or fuel down the intake and try to start it? 

 

Something to be going on with.

 

Edited August 11, 2018 by bmp01
Missing words added

[Sawchip]

I will add to the info already given by pointing out 2 things.

1 "Starts and runs lovely" .......maybe not 100% due to my second point.

2 ..A saw that has a carb + fuel system + correct tune all working properly is very unlikely to... "Run" ...on the choke setting unless it is a Injection carb used on some happy start Dolmar saws. 

The most "likely" situation is the "High idle" on a hot start not being used, and then, the possibility of the carburettor needing a new kit and service followed by the breakdown of the coil when its hot. 

[Swarf]

THANKS, for those replies. 

On 10/08/2018 at 19:47, peatff said:

That's a rear handle not a top handle  Try resetting the carb to manufacturer standard, screw the H & L screws in then something like one and a quarter turns out on each. It could be running weak on the L circuit. 

Well Peat, It looks like it was as simple as your advice...I made a L screw adjustment of 1/4 turn in plus an idle speed screw of 1/2 turn in which completly sorted it.

So simple but I have had this hot start problem before on B&S engines and had to replace the coil.

I have always liked the Sachs Dolmar saws, and they have a reputation for sound quality without being over complicated.

Yes it was my other saw, an Alpina that was a top handle one , not this ! Thanks to all,  Chris

Edited August 13, 2018 by Swarf
To modify composition.