MS261 Running issue

[Matthew Arnold]

I noticed today when stump treating the MS261 i was using was running fine with no problems with the chain brake off. Yet as soon as i put the brake on it died. Any ideas whats wrong with it?

[miker]

clutch springs??

[Matthew Arnold]

clutch springs??

 

That will be first port of call tomorrow. What is strange though is the chain isnt going round at all. Havent fiddled with (idle/fuel) screws but will be dimantling drive system tomorrow morning. The saw isnt even 6 months old so may be going back to dealer.

[ecolojim]

but err the chain shouldnt be going round with the brake on anyway

[WoodED]

That will be first port of call tomorrow. What is strange though is the chain isnt going round at all. Havent fiddled with (idle/fuel) screws but will be dimantling drive system tomorrow morning. The saw isnt even 6 months old so may be going back to dealer.

 

gd idea,,, swap it for a 346xp

[Matthew Arnold]

but err the chain shouldnt be going round with the brake on anyway

 

I know that. But i thought it was running fast and it only stopped as the chainbrake went on and stopped the clutch semi-biting thus killing the engine. Will phone dealer tomorrow (in town we are based in) to see what he suggests before i take the saw half apart. My boss had a look at it and so did the tree boys and they couldn't figure it out.

[spudulike]

If the clutch springs are bad, the chain will spin at low revs without the chainbrake on, it may well stall the saw with the chain brake engaged.

 

What is probably happening if the chain isn't spinning is that when the brake is engaged, it is putting force on to the sprocket bearing/thrust washers or sprocket drum and this is transferring to the crank shaft and this is enough to stall the engine at idle.

 

Take the clutch sprocket off and give the saw a good clean, lube the sprocket bearing, make sure the brake band hasn't got gunked up etc You may have a bit of twine, grass etc around the E clip/washer on the end of the crank or the end float on the sprocket has been taken up with crap.

 

You can take it frrom me that the brake is pushing the clutch drum in to a position that is causing enough friction on the crank to stall the saw!

[spudulike]

Oh - swap it for a 346XP:thumbup:

Couldn't resist!!

[Matthew Arnold]

If the clutch springs are bad, the chain will spin at low revs without the chainbrake on, it may well stall the saw with the chain brake engaged.

 

What is probably happening if the chain isn't spinning is that when the brake is engaged, it is putting force on to the sprocket bearing/thrust washers or sprocket drum and this is transferring to the crank shaft and this is enough to stall the engine at idle.

 

Take the clutch sprocket off and give the saw a good clean, lube the sprocket bearing, make sure the brake band hasn't got gunked up etc You may have a bit of twine, grass etc around the E clip/washer on the end of the crank or the end float on the sprocket has been taken up with crap.

 

You can take it frrom me that the brake is pushing the clutch drum in to a position that is causing enough friction on the crank to stall the saw!

 

 

Thank you. If you don't mind just printed that lot off to check for various wear/heat points. We had it on an old (1993) 034 we called "Herbie" as the stop switch didnt work. After running for 15 mins at full throttle the with the chain brake on it would still creep round very slowly. It didnt matter where it went it would come back the same. Sadly it was stolen with our 2 month old 361 and 4 month old FS450 and T516 tirfor winch. Boss hit the roof but wasnt our fault.

[spudulike]

Just seen that you said the idle is running fast - if this is the case then the clutch could be opening enough to touch the sprocket lightly - if this is the case - lower the idle to "normal" before digging in to the sprocket area!