Ms 341 starting issues

[Gmorgan]

Evening all,

 

i have an Ms341 that has recently been bogging down a little bit in the cut on diameters close to the bar length (18")

firstly I've cleaned the air filter (which was filthy), I've changed the fuel pick up body, I've changed the fuel tank breather, changed the clutch springs, a new sprocket and finally a new exhaust muffler. basically got a little bit carried away replacing things for shiny new ones. the carb has also been lightly cleaned inside and the diaphragm looks to be in good condition.

now its all back together i can't seem to keep it running. it will run for a few seconds on throttle then as soon as i click it to idle it will cut out after a second or so. another thing that may be an issue is how hard it has been to turn over since its all back together. if i remove the plug it turns over very well, the bore is score free e.t.c.

could it be the new exhaust that may be creating too much back pressure? would this also be a possible culprit for not keeping the saw running?

i may add that all new parts are genuine apart from the muffler can.

 

thanks in advance

George

[spudulike]

The exhaust won't be causing it unless the carb has been tuned for a knackered exhaust.

 

Have you adjusted the carb low screw and idle? It should be the first thing to do. Did you inspect the piston when you changed the muffler, was it in clean un-scored condition?

[Gmorgan]

The piston is score free and generally looks in good condition, the pull cord seems to have lots more resistance since I've put it all back together even though I never actually took the recoil apart not did I do anything with the the flywheel

[Gmorgan]

And no I havnt touched the carb adjustment at all yet

[spudulike]

When you replaced the clutch drum, did you align the small cut out with the arm on the oiler worm?

 

Did the clutch come off to replace the springs? Is the clutch drum free moving?

[Gmorgan]

I made double sure that the drum was aligned with the oiler worm. The drum is free moving and I didn't remove the clutch when I changed the springs but I did remove the clutch before so that I could clean behind it with the air line

[spudulike]

Interesting one, if the saw spins over ok with the plug removed then it should be just the compression causing the difficulty in turning it over!

 

If you are stuck, pop it round and I can have a look at it as you are around 40 mins away!

[Gmorgan]

That's brilliant I may well take you up on that offer, I'm missing the fuel hose at the moment as I've managed to split it trying to see if it was perished.

[peatff]

That's brilliant I may well take you up on that offer, I'm missing the fuel hose at the moment as I've managed to split it trying to see if it was perished.

 

That's a pretty good sign that it was perished. Have you still got the old silencer if you suspect the new one of being restrictive ?

[spudulike]

That's a pretty good sign that it was perished. Have you still got the old silencer if you suspect the new one of being restrictive ?

 

The only time I have known the muffler area to restrict the saw turning over is when vacuum/pressure checking and the port is completely blocked off.

 

The last thing worth trying is to remove the clutch drum and recoil cover and then turn the engine over with no plug in by turning the flywheel by hand slowly and see if the saw is loose or tight when turning over. Repeat with the plug in and experiment with the decomp in and out.

 

I don't know why the compression should suddenly go up, a dry saw will have less compression than one that has run a few hours earlier down to the better seal the fuel creates around the piston but what you have done shouldn't effect the idle unless something is binding around the clutch area and stopping the machine idling but apart from that.......it is weird and may just need a tweak on the idle speed!