660!!!!!!!!!!

[Isabelle68]

My 660 let me down yesterday! Its a 2005 model but hasnt done much work, it starts and revs for 20 secs or so sounding good then stops abruptly, i stripped the carb today but found nothing and the problem persists, any ideas???

[Eddy_t]

Light seize? Or coil!

[Logit]

Fuel filter and/or air filter need cleaning ?

Leak in fuel pipe ?

[Jonathan O'Leary]

Had the same on my 084, turned out head bolts had come undone slightly so as it heated everything expanded and then stopped.

Could be vacuum in tank, after it stops undo tank, close and try again

Good luck sorting it

[Mortimer Firewood]

My 660 let me down yesterday! Its a 2005 model but hasnt done much work, it starts and revs for 20 secs or so sounding good then stops abruptly, i stripped the carb today but found nothing and the problem persists, any ideas???

 

If it's not done much work has it been left for long periods with fuel left in it as it goes stale and will cause problems.

[spudulike]

You need to ascertain what is missing, fuel, compression or spark.

 

You say the carb is OK - most common issues here will be fuel pipe, blocked internal gauze filter or split impulse line.

 

Compression either test or take off the muffler and look for those tell tail vertical scores on the piston.

 

Spark - change the plug and check the flywheel magnets to coil gap = a business card will be the correct gap.

 

Report back with how it goes - if you get stuck, you know where I am:thumbup:

[Isabelle68]

When i stripped the carb it all seemed clean and good, no fuel leaks, seems to be tons of compression, it starts quickly and correctly and it sounds and feels how a 660 should smooth and revving out properley etc, if any of my stuff hasnt been used for a month or so i always tip the tank out and put fresh fuel in it (i know there could be some old fuel still in carb) i use stihl two stroke and never buy my fuel from supermarkets! So god knows fella,s!!! I,m no saw doctor i cut trees down and catch lobsters for a living!! Hmmm maybe i should use it as an anchor!!

[NFG]

Hi

 

How about checking the breather from the fuel tank (I dont know a 660 but I guess its similar to other Stihls) the tube may have some info

 

If the breather was clogged then you'd pull a vacuum in your tank after a short time then run out.

 

& if you remove the spark plug & check the colour - it should be a nice biscuit brown colour if you know what I mean - not grey or white too weak & as Spud said about a CC gap - 25 thou seems to ring a bell or thereabouts.

 

Edit Googled spec for 660 seems to be .020" so 20 thou - that right Spud?

 

dont think a couple o thou here or there is going to cause your snag but worth a look as I had a strimmer that cut out like yours, took plug out & big lump of muck on plug cleaned off ran fine but I would have thought it wouldnt have started at all

 

N

Edited February 25, 2015 by NFG

[Isabelle68]

Ive had vacuum probs with outboards before when ive forgotton to open the breather screw on the tank so am i right in thinking if i can get it to run for long enough to turn it on its side and open the fuel cap if it runs then its a vac issue? I,ll try that

[swinny]

Ive had vacuum probs with outboards before when ive forgotton to open the breather screw on the tank so am i right in thinking if i can get it to run for long enough to turn it on its side and open the fuel cap if it runs then its a vac issue? I,ll try that

 

Only half / quarter fill with fuel. Leave saw on the ground then try the fuel cap